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Red Hat Linux 7.3 The Official Red Hat Linux

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1. bootproto bootp The line for static networking is more complex as you must include all network config uration information on one line You must specify e IP address e Netmask e Gateway IP address e Nameserver IP address Here is an example static line network bootproto static ip 10 0 2 15 netmask 255 255 255 0 gateway 10 0 2 254 nameserver 10 0 2 1 If you use the static method be aware of the following two restrictions All static networking configuration information must be specified on one line you cannot wrap lines using a backslash for example e You can only specify one nameserver here However you can use the kickstart file s post section described in Section 1 4 31 to add more name servers if needed 1 4 19 part part Or partition required for installs ignored for upgrades Creates a partition on the system The lt mntpoint gt is where the partition will be mounted and must be of one of the following forms lt mntpoint gt For example usr home swap The partition will be used as swap space To determine the size of the swap partition automatically use the recommended option swap recommended 1 This option is new to Red Hat Linux 7 3 Chapter 1 Kickstart Installations 31 The minimum size of the automatically generated swap partition will be no smaller than the amount of RAM in the system and no bigger than twice the amount of RAM in the system raid
2. 13 5 Performance Tuning Click on the Performance Tuning tab to configure the maximum number of child server processes you want and to configure the Apache options for client connections The default settings for these options are appropriate for most situations Altering these settings may affect the overall performance of your Web server Main Virtual Hosts Server Performance Tuning Servers Max Number of Connections 150 a Connections Connection Timeout 300 4 w Allow unlimited requests per connection A Max requests per connection 100 Requests per Connection J Allow Persistent Connections Timeout for next Connection 115 4 DoK amp Cancel Help Figure 13 14 Performance Tuning Set Max Number of Connections to the maximum number of simultaneous client requests that the server will handle For each connection a child httpd process is created After this maximum number of process is reached no one else will be able to connect to the Web server until a child server process is freed You can not set this value to higher than 256 without recompiling Apache This option corresponds to the MaxClients directive Connection Timeout defines in seconds the amount of time that your server will wait for re ceipts and transmissions during communications Specifically Connection Timeout defines how long your server will wait to receive a GET request how long it will wait to receive TCP packets on a POST or
3. 162 Chapter 17 Console Access cp etc pam d halt etc pam d foo Now when you run usr bin foo it will call consolehelper which will authenticate the user with the help of usr sbin userhelper To authenticate the user consolehelper will ask for the user s password if etc pam d foo is a copy of etc pam d halt otherwise it will do precisely what is specified in etc pam d foo and then run usr sbin foo with root permissions 17 7 The floppy Group If for whatever reason console access is not appropriate for you and you need to give non root users access to your system s diskette drive this can be done using the floppy group Simply add the user s to the floppy group using the tool of your choice Here is an example showing how gpasswd can be used to add user fred to the floppy group root bigdog root gpasswd a fred floppy Adding user fred to group floppy root bigdog root Now user fred will now be able to access the system s diskette drive from the console D reana Chapter 18 Time and Date Configuration Red Hat Linux no longer includes timetool The dateconfig utility has replaced timetool The dateconfig application allows the user to change the system date and time to configure the time zone used by the system and to setup the Network Time Protocol NTP daemon to synchronize the system clock with a time server To use dateconfig you must be running the X Window System and have root privileges To
4. 22 3 2 Configuring Batch Jobs To execute a one time task when the load average is below 0 8 use the bat ch command After typing the batch command the at gt prompt is displayed Type the command to ex ecute press Enter and type Ctrl D More than one command can be specified by typing each command followed by the Enter key After typing all the commands press Enter to go to a blank line and type Ctrl D Alternatively a shell script can be entered at the prompt pressing Enter after each line in the script and typing Ctrl D on a blank line to exit If a script is entered the shell used is the shell set in the user s SHELL environment the user s login shell or bin sh whichever is found first As soon as the load average is below 0 8 the set of command or script is executed If the set of commands or script tries to display information to standard out the output is emailed to the user Use the command atq to view pending jobs Refer to Section 22 3 3 for more information Usage of the bat ch command can be restricted Refer to Section 22 3 5 for details 22 3 3 Viewing Pending Jobs To view pending at and batch jobs use the atq command It displays a list of pending jobs with each job on a line Each line is in the format job number date hour job class and username Users can only view their own jobs If the root user executes the atq command all jobs for all users are displayed 202 Chapter 22 Automated T
5. In traditional also known as snail mail letters are usually sealed within envelopes stamped and delivered from post office branch to branch until they reach their destination But sending mail through the Internet is much less secure email is usually transmitted as unencrypted text from server to server No special steps are taken to protect your correspondence from being seen or tampered with by other people To help you protect your privacy Red Hat Linux 7 3 includes GnuPG the GNU Privacy Guard which is installed by default during a typical Red Hat Linux installation It is also referred to as GPG GnuPG is a tool for secure communication it is a complete and free replacement for the encryption technology of PGP Pretty Good Privacy a widely popular encryption applica tion Using GnuPG you can encrypt your data and correspondence and authenticate your correspondence by digitally signing your work GnuPG is also capable of decrypting and verifying PGP 5 x Because GnuPG is compatible with other encryption standards your secure correspondence will probably be compatible with email applications on other operating systems such as Windows and Macintosh GnuPG uses public key cryptography to provide users with a secure exchange of data In a public key cryptography scheme you generate two keys a public key and a private key You exchange your public key with correspondents or with a keyserver you should never reveal your private
6. e a queries all currently installed packages e f lt file gt will query the package which owns lt file gt When specifying a file you must specify the full path of the file for example usr bin 1s e p lt packagefile gt queries the package lt packagefile gt There are a number of ways to specify what information to display about queried packages The following options are used to select the type of information for which you are searching These are called Information Selection Options i displays package information including name description release size build date install date vendor and other miscellaneous information 1 displays the list of files that the package contains s displays the state of all the files in the package a displays a list of files marked as documentation man pages info pages READMEs etc c displays a list of files marked as configuration files These are the files you change after installation to adapt the package to your system for example sendmail cf passwd inittab etc For the options that display lists of files you can add v to the command to display the lists in a familiar 1s 1 format 25 2 7 Verifying Verifying a package compares information about files installed from a package with the same information from the original package Among other things verifying compares the size MD5 sum permissions type owner and group of each file The command rpm
7. 0K X Cancel Help i Figure 13 11 Name Based Virtual Hosts 13 3 1 2 SSL rote You can not use name based virtual hosts with SSL because the SSL handshake when the browser accepts the secure Web server s certificate occurs before the HTTP request which identifies the appropriate name based virtual host If you want to use name based virtual hosts they will only work with your non secure Web server If an Apache server is not configured with SSL support communications between an Apache server and its clients are not encrypted This is appropriate for websites without personal or confidential information For example an open source website that distributes open source software and documentation has no need for secure communications However an ecom merce website that requires credit card information should use the Apache SSL support to encrypt its communications Enabling Apache SSL support enables the use of the mod_ss1 security module To enable it through Apache Configuration Tool you must allow access through port 443 under the Main tab gt Available Addresses Refer to Section 13 1 for de tails Then select the virtual host name in the Virtual Hosts tab click the Edit button choose SSL from the left hand menu and check the Enable SSL Support option as shown in Figure 13 12 The SSL Configuration section is pre configured with the dummy digital certificate The digital certificate provides authentication for your secure W
8. Figure 26 6 Network Settings In Rpmfind and Distributions you will find settings and options which correspond to the Web find feature The Rpmfind system allows the user to search the Internet for packages by name summary architecture and more see Figure 26 7 The user is then given the option of downloading and installing the most appropriate packages for their system To learn more about Rpmfind go to http rpmfind net Chapter 26 Gnome RPM 237 Efon Packages not produced by Red Hat are not supported by Red Hat because Red Hat can not verify the integrity of these packages and how they interact with official Red Hat packages Use caution when installing packages downloaded using Rpmfind Behaviour Package Listing Install Window Network Rpmfind Distributions Rpmfind Options Metadata Server http Aww redhat com RDF A Download dir root rams A Browse Vendor Red Hat Inc Distrib BlueSky _ Want sources _j Want latest version No Upgrade List flibe Bok Apply X Close Help Figure 26 7 The Rpmfind Window The Metadata server sets the server to be used for searches The Download dir entry allows you to specify where you want the files to be placed You can also specify the vendor distribution name and whether to find sources and or the latest files 238 Chapter 26 Gnome RPM Behaviour Package Listing Install Window Network Rpmfind Distribution
9. cen20dJt ToAF 6fGnikeCeP105aWTbDgdAUHBRykpdWU3GJ7NS 6923 fVg5khOWg uwrAiEYEGBECAAYFAjkHP4wACgkOkOKa8YI9JamliwCfXox HjlorMKnOQRJkeBcZ iLyPH1QA0I33Ft OHBqLt qdtP4vWYORbibjW BMEc Appendix B Getting Started with Gnu Privacy Guard 257 B 4 1 Exporting to a Keyserver If you are only writing to a few correspondents you can export your public key and send it to them personally If you correspond with many people however distribution of your key can be time consuming Instead you can use a keyserver File Edit View Go Communicator Help i e2 2 22ed ss F 4 s Bookmarks A Location http www keyserver net en A E7 What s Related lt Q FIND amp KEY CHOOSE ANOTHER CRYPTO ABOUT ez EMAIL THE more settings KEY SERVER INFO THIS SERVER WEBMASTER OPENPGP PUBLIC KEY SERVER Welcome to www keyserver net je 100 Figure B 1 The Home Page of Keyserver Net A keyserver is a repository on the Internet which can store and distribute your public key to anyone who requests it Many keyservers are available and most try to remain synchronized with each other sending your key to one keyserver is like distributing it to them all A correspondent can request your public key from a from a keyserver import that key to their keyring and they are ready for secure correspondence with you rip Because most keyservers are synchronized sending your public key to one keyserver is usually as
10. 0 9 and _ They must begin with letters Queue Name test Queue Type C Local Printer LOCAL Unix Printer LPD C Windows Printer SMB C Novell Printer NCP C JetDirect Printer JETDIRECT lt Back gt Next amp Cancel 1 Figure 21 5 Adding a Remote Printer Text fields for the following options appears as shown in Figure 21 6 Server The hostname or IP address of the remote machine to which the printer is at tached e Queue The remote printer queue The default printer queue is usually 1p By default the Strict RFC1179 Compliance option is not chosen If you are having problems printing to a non Linux 1pd queue choose this option to disable enhanced LPRng printing features Click Next to continue Configure a Unix Print Queue Configure the server and queue of your remote Ipd server If no queue is specified you will use the default queue on the remote server Select strict RFC1179 compliance if you are having problems connecting to an older Ipd server Server servername Queue p P Strict RFC1179 Compliance a gt Next amp Cancel Figure 21 6 Choosing the Printer Server The next step is to select the type of printer that is connected to the remote system Skip to Section 21 6 to continue 184 Chapter 21 Printer Configuration Os The remote machine must be configured to allow the local machine to print on the desired queue As root creat
11. Allows you to specify a different scripting language such as Perl Replace usr bin per1 with the scripting language of your choice The following example uses a Perl script to replace etc HOSTNAME Spost interpreter usr bin perl replace etc HOSTNAME open HN gt HOSTNAME print HN 1 2 3 4 an ip address n More examples of post installation scripts can be found in Section 2 11 1 4 32 include Include Contents of Another File Section Use the include path to file command to include the contents of another file in the kickstart file as though the contents were at the location of the include command in the kickstart file 1 This option is new to Red Hat Linux 7 3 Chapter 1 Kickstart Installations 39 1 5 Where to Put A Kickstart File A kickstart file must be placed in one of two locations e Ona boot disk e Ona network Normally a kickstart file is copied to the boot disk or made available on the network The network based approach is most commonly used as most kickstart installations tend to be performed on networked computers Let us take a more in depth look at where the kickstart file may be placed 1 5 1 Creating a Kickstart Boot Disk To perform a diskette based kickstart installation the kickstart file must be named ks cfg and must be located in the boot disk s top level directory Note that the Red Hat Linux boot disks are in MS DOS format so it is easy to copy the kickstart file under
12. Maintainer of the Official Red Hat Linux Reference Guide John Ha Technical Writer Contributing Writer to the Official Red Hat Linux Getting Started Guide Table of Contents Tinto d Chi Oi seveasescscsctisteinsshescascaueesieebcscacaaasesucasdecaaaa icnsacashaa OEE aANT EEAS TO itet ESAS Eies aSa ix T Changes to This Ma uals sirieias iea a ix 2 Document Conventions xX 3 More to Come w eceeeccseseeeeseeseees xiii 3 1 Send in Your Feedback Xiii 4 Sign Up for Suppott 04 xiv I Installation Related Reference s sesesessossessesesescsesesescesossessosesesosesesesescoeeessssesosesssesesesesesesessese xv Te Kickstart Installieren 17 1 1 What are Kickstart Installations 0 17 1 2 How Do You Perform a Kickstart Installation 1 3 Creating the Kickstart File cccsceeees ee 1 4 Kickstart Options 0 18 1 5 Where to Put A Kickstart File we 38 1 6 Starting a Kickstart Installation 40 2 Kickstart Configuratot 0 0000 43 2 1 Basic Configuration 2 2 Boot Loader Options 2 3 Installation Method 45 2 4 Partition Information we 46 2 5 Network Configuration uw47 2 6 Authentication 48 2 7 Firewall Configuration we AO 2 8 X Configuration 50 2 9 Package Selection 53 2 10 Pre InstallatiOn Script oseyi eetis seeiis seee K E aas 53 2 11 Post Install tion Script znicit pa aea 54 2 12 S
13. The hardware based system manages the RAID subsystem independently from the host and presents to the host only a single disk per RAID array An example of a Hardware RAID device would be one that connects to a SCSI controller and presents the RAID arrays as a single SCSI drive An external RAID system moves all RAID handling intelligence into a controller located in the external disk subsystem The whole subsystem is connected to the host via a normal SCSI controller and appears to the host as a single disk RAID controllers also come in the form of cards that act like a SCSI controller to the operating system but handle all of the actual drive communications themselves In these cases you plug the drives into the RAID controller just like you would a SCSI controller but then you 64 Chapter 4 Redundant Array of Independent Disks RAID add them to the RAID controller s configuration and the operating system never knows the difference 4 3 2 Software RAID Software RAID implements the various RAID levels in the kernel disk block device code It offers the cheapest possible solution as expensive disk controller cards or hot swap chassis 1 are not required Software RAID also works with cheaper IDE disks as well as SCSI disks With today s fast CPUs Software RAID performance can excel against Hardware RAID The MD driver in the Linux kernel is an example of a RAID solution that is completely hard ware independent The performance
14. for example in an XTerm or GNOME terminal 2 1 Basic Configuration File Help Basic Configuration required asic Configuration Boot Loader Options Language English j Installation Method Partition Information Keyboard U S English Network Configuration Authentication Mouse Probe for Mouse x Firewall Configuration X Configuration Emulate 3 Buttons Package Selection Pre Installation Script Time Zone America New_York Post Installation Script Root Password I Encrypt root password Language Support Chinese Mainland a Chinese Taiwan ined Czech Danish xj IZ Reboot system after installation Perform installation in text mode graphical is default Perform installation in interactive mode Save File X Cancel 2 Help Figure 2 1 Basic Configuration Choose the language to use during the installation from the Language menu Select the system keyboard type from the Keyboard menu Choose the mouse for the system from the Mouse menu If you choose No Mouse no mouse will be configured If you choose Probe for Mouse the installation program will try to au todetect the mouse Probing works for most modern mice 44 Chapter 2 Kickstart Configurator If you have a two button button mouse you can emulate a three button mouse by selecting Emulate 3 Buttons If this option is selected simultaneously clicking the left and right mouse buttons will be recognized as a
15. good as sending it to them all You can however locate different keyservers One place to begin your search for keyservers and more information is Keyserver Net at http www keyserver net another location is Robert s Crypto amp PGP Links Keyservers at http crypto yashy com www Keyservers You can send your public key from either the shell prompt or from a browser as in Figure B 1 of course you must be online to send or receive keys from a keyserver From the shell prompt type the following gpg keyserver search keyserver net send key you yourisp net 258 Appendix B Getting Started with Gnu Privacy Guard From your browser go to Keyserver Net http www keyserver net and select the option to add your own PGP public key Your next task is to copy and paste your public key into the appropriate area on the Web page If you need instructions on how to do that use the following Open your exported public key file such as mykey asc which was created in Section B 4 with a pager for example use the less mykey asc command e Using your mouse copy the file by highlighting all the lines from the BEGIN PGP to END PGP notations see Figure B 2 e Paste the contents of the file mykey asc into the appropriate area of the page on Key server Net by middle clicking with your mouse or left and right clicking if you re us ing a two button mouse Then select the Submit button on the keyserver page If you
16. newer version You can also drag and drop packages from Nautilus Within Nautilus left click on the se lected package While still holding down the mouse button drag the file to the Install win dow and place it within the Name panel When dragging files to the Install window from Nautilus you will notice that the file is displayed as an icon while it is being dragged toward Gnome RPM Once inside the Name panel you will see that the package is checked for installation by default and its information appears in the Package Info panel to the right To install the package select the Install button You will see a progress indicator as your package is being installed 234 Chapter 26 Gnome RPM 26 4 Configuration Gnome RPM offers a wide selection of choices for installing and uninstalling packages doc umentation and other features You can customize Gnome RPM using the Preferences dia log which you can access from Operations gt Preferences on the menu To make selections in the Preferences dialog select the boxes next to the options Under the Behaviour tab you will find a number of options for configuring the way Gnome RPM installs uninstalls and upgrades packages The Behaviour tab is divided into five sec tions Install Options Upgrade Options Other Options Database Options and Architec ture Options Note that by default these boxes are not selected see Figure 26 4 Behaviour Package Listing install Window Ne
17. start dateconfig use one of the following methods On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt Date Time Properties e On the KDE desktop go to the Main Menu Button on the Panel gt System gt Date Time Properties Type the command dateconfigata shell prompt for example in an XTerm or a GNOME terminal 18 1 Time and Date Properties As shown in Figure 18 1 the first tabbed window that appears is for configuring the system date and time and the NTP daemon nt pa 1 If you type timetool at a shell prompt Dateconfig will start 164 Chapter 18 Time and Date Configuration Date amp Time Time Zone Date gt Time 4 2001 gt Current Time 17 38 11 Hour 17 3 4 5 6 7 amp 9 1 1 Ae Ws 4 1S 16 Minute 36 I el a PA ea 24 25 zt 26 293 730 Secondi j gt Network Time Protocol Your computer can synchronize its clock with a remote time server using the Network Time Protocol daemon _j Enable Network Time Protocol Server Bok X Cancel yf Apply Help Figure 18 1 Time and Date Properties To change the date use the arrows to the left and right of the month to change the month Use the arrows to the left and right of the year to change the year and click on the day of the week to change the day of the week Changes will not take place until you click the Apply button To change the time use the up and dow
18. usr share locale ru LC_MESSAGES sndconfig mo usr share locale sk LC_MESSAGES sndconfig mo usr share locale sl LC_MESSAGES sndconfig mo usr share locale sr LC_MESSAGES sndconfig mo usr share locale sv LC_MESSAGES sndconfig mo usr share locale tr LC_MESSAGES sndconfig mo usr share locale uk LC_MESSAGES sndconfig mo Chapter 25 Package Management with RPM 227 usr share man man8 pnpprobe 8 gz usr share man man8 sndconfig 8 gz usr share sndconfig sample au usr share sndconfig sample midi These are just a few examples As you use it you will find many more uses for RPM 25 5 Additional Resources RPM is an extremely complex utility with many options and methods for querying in stalling upgrading and removing packages Refer to the following resources to learn more about RPM 25 5 1 Installed Documentation e rpm help This command displays a quick reference of RPM parameters e man rpm The RPM man page will give you more detail about RPM parameters than the rpm help command 25 5 2 Useful Websites http www rpm org The RPM website http www redhat com mailing lists The RPM mailing list is archived here To sub scribe send mail to lt rpm list request redhat com gt with the word subscribe in the subject line 25 5 3 Related Books e Maximum RPM by Ed Bailey Red Hat Press An online version of the book is available at http www rpm org and http www redhat com do
19. v verifies a package You can use any of the Package Selection Options listed for querying to specify the packages you wish to verify A simple use of verifying is rpm V foo which verifies that all the files in the foo package are as they were when they were originally installed For example e To verify a package containing a particular file rpm Vf bin vi e To verify ALL installed packages rpm Va Chapter 25 Package Management with RPM 223 e To verify an installed package against an RPM package file rpm Vp foo 1 0 1 i386 rpm This command can be useful if you suspect that your RPM databases are corrupt If everything verified properly there will be no output If there are any discrepancies they will be displayed The format of the output is a string of eight characters a c denotes a configuration file and then the file name Each of the eight characters denotes the result of a comparison of one attribute of the file to the value of that attribute recorded in the RPM database A single a period means the test passed The following characters denote failure of certain tests e 5 MD5 checksum e s file size it symbolic link T file modification time e D device e U user G group M mode includes permissions and file type e unreadable file If you see any output use your best judgment to determine if you should remove or reinstall the package or fix the problem in anoth
20. 0 enter 192 168 10 in the IP Address first 3 Octets text area A new window will appear as shown in Figure 15 3 with the following options 1 IP Address The first three octets that you just entered in the previous window 2 Reverse IP Address Non editable Pre populated based on the IP Address entered 3 File Name File name of DNS database file in the var named directory 4 Primary Name Server SOA State of authority SOA record This specifies the name server that is the best resource of information for this domain The default value is which means that the SOA is the same as the domain name entered in the Name field above 5 Time Settings The Refresh Retry Expire and Minimum TTL Time to Live values that are stored in the DNS database file 6 Name Servers Add edit and delete name servers for for the reverse master zone At least one name server is required 7 Reverse Address Table List of IP addresses within the reverse master zone and their hostnames For example for the reverse master zone 1 2 3 you can add 1 2 3 100 in the Reverse Address Table with the hostname foo example com The hostname must end with a period to specify that it is a full hostname Chapter 15 BIND Configuration 153 Reverse Master Zone IP Address feo Reverse IP Address 3 2 1 in addr arpa File Name 3 2 1 in addr arpazone Primary Name Server 50A ie Time Settings Name Servers Rever
21. 0 0 0 0 SW 0 0 0 0 0 29 kswapd 347 root 0 0 556 556 460 S 0 0 0 2 0 00 syslogd 357 root 0 0 MEZ AAZ 360 S 0 0 0 2 0 00 klogd 372 bin 0 0 692 692 584 S 0 0 0 2 0 00 portmap 388 root 0 0 0 0 0 SW 0 0 0 0 0 00 lockd 389 root 0 0 0 0 0 SW 0 0 0 0 0 00 rpciod 414 root 0 0 436 432 372 8 0 0 O 1 0 00 apmd 476 root 0 0 592 3592 496 S 0 0 0 2 0 00 automount To exit top press the q key Useful interactive commands that you can use with top include the following 172 Chapter 20 Gathering System Information Table 20 1 Interactive top commands Space Immediately refresh the display Display a help screen h k In Kill a process You will be prompted for the process ID and the signal to send to it Change the number of processes displayed You will be prompted to enter the number u Sort by memory usage Sort by CPU usage If you would like to use a graphical interface for top you can use the GNOME System Monitor To start it on the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt System Monitor or type gtop at a shell prompt from within any X Window System desktop File View Settings Windows Help root 9 63620 63620 1 3 1 03h fetc K11 tfox 0 3064 3064 5 04m magicdey tfox 4388 4388 R 3 38m gtop tfox 41132 41132 1 15m usr lib netscape ne tfox 11008 11008 5 43 97s emacs root 0 0 SU 29 58s kswapd root 0 0 SU 2481s kupdate tfox 6772 6772 23 69s emacs tfox 3584
22. 11 2 Useful Websites http www modssl org The mod_ss1 website is the definitive source for information about mod_ss1 The website includes a wealth of documentation including a User Manual at http www modssl org docs 14 11 3 Related Books Apache The Definitive Guide 2nd edition by Ben Laurie and Peter Laurie O Reilly amp Asso ciates Inc reana Chapter 15 BIND Configuration This chapter assumes that you have a basic understanding of BIND and DNS it does not attempt to explain the concepts of BIND and DNS This chapter does explain how to use the BIND Configuration Tool bindconf to configure basic BIND server zones for BIND ver sion 8 The BIND Configuration Tool creates the etc named conf configuration file and the zone configuration files in the var named directory each time you apply your changes If you require more functionality than this tool provides you can create the etc named conf configuration file using the BIND Configuration Tool and then add your customized settings However once you manually modify the configuration file you cannot use BIND Configuration Tool to edit the custom configuration settings that were added manually Oimportant Do not edit the etc named conf configuration file BIND Configuration Tool generates this file after you apply your changes If you want to configure settings that are not configurable using BIND Configuration Tool then do not use it The BIND Configur
23. 128 Mirage 2 128 zj Video Card RAM 32 MB x T Save File X Cancel Figure 2 10 X Configuration Video Card 2 8 3 Monitor After configuring the video card click on the Monitor tab shown in Figure 2 11 Probe for monitor is selected by default Accept this default if you want the installation pro gram to probe for the monitor during installation Probing works for most modern monitors If you select this option and the installation program can not successfully probe the moni tor the installation program will stop at the monitor configuration screen To continue the installation process select your monitor from the list and click Next Alternatively you can select your monitor from the list You can also specify the horizontal and vertical sync rates instead of specifying a monitor by checking the Specify hysnc and vsync instead of monitor option This option is useful if the monitor for the system is not listed Notice that when this option is enabled the monitor list is disabled Chapter 2 Kickstart Configurator File Help X Configuration Basic Configuration Boot Loader Options IZ Configure the X Window System Installation Method Partition Information General Video Card Monitor Network Configuration Authentication T Probe for monitor Firewall Configuration Select a Monitor el Package Selection Pre Installation Script Dell P790 Post Installation Scrip
24. 215 25 Package Management With RPM cccscsessessesesesseeseesesteseeseeesseseesessesesesseesesees 217 25 1 RPM Design Goals 25 2 Using RPM ccccccsceseeeseeeees 25 3 Checking a Package s Signature cccccsecsessesseseesesesteseeseeestesteseeseaneseess 223 25 4 Impressing Your Friends with RPM c ccccscsssssesesseesesseseesesteseeseeneane 224 25 5 Additional Resources 26 Gnome RPM ccceceeeeeseeeees 26 1 Starting Gnome RPM c cecccsccsccs esses sees eeseesessesseseeseeseseseesesseaneseseaseasens 26 2 The Package Display ccscesccsessecsesseseessssesteseeessestssneseesessseeseeseasssneseeseanens 26 3 Installing New Packages n 26 4 Configuration 26 5 Package Manipulation 27 Red Hat Network cc0c00 V Appendixes cccecsessssssseessesesseseenessessssssncsncsssssneensssessenesnssncssencsnsensseenesnessssneaeencsnsseneensensseneenes A Building a Custom Kernel c ccccsccscsssessssesseseesseseesessesseseesesseseesesseasssesesseeseaneseeseenes A 1 Building a Modularized Kernel 5 A 2 Making an initrd Image ccccescescsesseesesteseeseesesseseeseeseesesteseesessesesneseanesnens A 3 Configuring the Boot Loader sssini A A Building a Monolithic Kernel z A 5 Additional Resources B Getting Started with Gnu Privacy Guard B 1 An Introduction to GnuPG B 2 Generating a Keypair
25. 4 5 Configuring ssh agent The ssh agent can be used to store your passphrase so that you do not have to enter it each time you make a ssh or scp connection If you are not running the X Window System follow these steps from a shell prompt If you are running GNOME but you do not want to configure it to prompt you for your passphrase when you log in see Section 9 3 4 4 this procedure will work in a terminal window such as an xterm If you are running X but not GNOME this procedure will work in a terminal window such as an xterm However your passphrase will only be remembered for that terminal window it is not a global setting 1 Ata shell prompt type the following command exec usr bin ssh agent SHELL Then type the command ssh add and enter your passphrase s If you have more than one key pair configured you will be prompted for each one 2 When you log out your passphrase s will be forgotten You must execute these two commands each time you log in to a virtual console or open a terminal window 9 4 Additional Resources The OpenSSH and OpenSSL projects are in constant development so the most up to date information for them will be found on their websites The man pages for OpenSSH and OpenSSL tools are also good sources of detailed information 9 4 1 Installed Documentation e The ssh scp sftp sshd and ssh keygen commands These man pages include infor mation on how to use these commands as well as all th
26. 85 rote The name servers section does not configure the system to be a name server If the DNS server names are retrieved from DHCP or retrieved from the ISP of a modem connection do not add primary secondary or tertiary DNS servers 86 Chapter 6 Network Configuration reana Chapter 7 Basic Firewall Configuration Just as a firewall in a building attempts to prevent a fire from spreading a computer fire wall attempts to prevent computer viruses from spreading to your computer and to prevent unauthorized users from accessing your computer A firewall exists between your computer and the network It determines which services on your computer remote users on the net work can access A properly configured firewall can greatly increase the security of your system It is recommended that you configure a firewall for any Red Hat Linux system with an Internet connection During the Firewall Configuration screen of the Red Hat Linux installation you were given the option to choose a high medium or no security level as well as allow specific devices incoming services and ports These levels are based on the GNOME Lokkit firewall config uration application After installation you can change the security level of your system by using GNOME Lokkit GNOME Lokkit allows you to configure firewall settings for an average user by construct ing basic ipchains networking rules Instead of having to write the rules this program asks you
27. 9 and _ They must begin with letters Queue Name test5 Queue Type C Local Printer LOCAL C Unix Printer LPD C Windows Printer SMB C Novell Printer NCP JetDirect Printer JETDIRECT lt q Back gt Next X amp Cancel Figure 21 11 Adding a JetDirect Printer Text fields for the following options appear below the Queue Type menu as shown in Figure 21 12 Printer IP The hostname or IP address of the JetDirect printer Port The port on the JetDirect printer that is listening for print jobs 188 Chapter 21 Printer Configuration Configure a Jetdirect Printer Enter the IP address of the JetDirect printer Use the default port of 9100 unless you know the printer is using a different port Printer IP printer example com Port 9100 lt Back gt Next X amp Cancel Figure 21 12 Choosing a Print Server The next step is to select the type of printer that is connected to the JetDirect system Skip to Section 21 6 to continue 21 6 Selecting the Print Driver and Finishing After selecting the queue type of the printer the next step in adding a printer is to select the print driver You will see a window similar to Figure 21 13 If you are configuring a local printer select the print driver from the list The printers are divided by manufacturers Click the arrow beside the manufacturer for your printer Find your printer from the expanded list and click the ar
28. B 3 Generating a Revocation Certificate B 4 Exporting your Public Key B 5 Importing a Public Key 1258 B 6 What Are Digital Signatures 259 B 7 Additional Resources 25 5 18 askiei ides RAPA AR i A 259 3 redhat Welcome to the Official Red Hat Linux Customization Guide The Official Red Hat Linux Customization Guide contains information on how to customize your Red Hat Linux system to fit your needs If you are looking for a step by step task oriented guide for configuring and customizing your system this is the manual for you This manual discusses many intermediate topics such as the following Introduction Setting up a network interface card NIC Performing a Kickstart installation Configuring Samba shares e Managing your software with RPM e Determining information about your system Upgrading your kernel This manual is divided into the following main categories Installation Related Reference e Network Related Reference e System Configuration e Package Management This guide assumes you have a basic understanding of your Red Hat Linux system If you need reference material which covers more basic issues such as configuring your desktop or playing audio CD RPMs please refer to the Official Red Hat Linux Getting Started Guide If you need more advanced documentation such as an overview of the Red Hat Linux filesystem please refer to the Official Red Hat Linux Reference Guide HTML
29. Chapter 9 OpenSSH OpenSSH is a free open source implementation of the SSH Secure SHell protocols It re places telnet ftp rlogin rsh and rcp with secure encrypted network connectivity tools OpenSSH supports versions 1 3 1 5 and 2 of the SSH protocol Since OpenSSH version 2 9 the default protocol is version 2 which uses RSA keys as the default 9 1 Why Use OpenSSH If you use OpenSSH tools you are enhancing the security of your machine All commu nications using OpenSSH tools including passwords are encrypted Telnet and ftp use plaintext passwords and send all information unencrypted The information can be inter cepted the passwords can be retrieved and then your system can be compromised by an unauthorized person logging in to your system using one of the intercepted passwords The OpenSSH set of utilities should be used whenever possible to avoid these security problems Another reason to use OpenSSH is that it automatically forwards the DISPLAY variable to the client machine In other words if you are running the X Window System on your local machine and you log in to a remote machine using the ssh command when you execute a program on the remote machine that requires X it will be displayed on your local machine This is convenient if you prefer graphical system administration tools but do not always have physical access to your server 9 2 Configuring an OpenSSH Server To run an OpenSSH server you must first
30. Figure 21 16 will appear The window contains the current values for the printer that you selected to edit Make any changes and click OK Click Apply in the main printconf window to save the changes and restart the printer daemon Chapter 21 Printer Configuration 191 Name and Aliases Queue Type Driver Driver Options Queue Name test 4 oK amp Cancel Help Figure 21 16 Editing a Printer 21 8 1 Names and Aliases If you want to rename a printer change the value of Queue Name in the Names and Aliases tab Click OK to return to the main window The name of the printer should change in the printer list Click Apply to save the change and restart the printer daemon A printer alias is an alternate name for a printer To add an alias for an existing printer click the Add button in the Name and Aliases tab enter the name of the alias and click OK Click OK again to return to the main window Click Apply to save the aliases and restart the printer daemon A printer can have more than one alias 21 8 2 Queue Type The Queue Type tab shows queue type that you selected when adding the printer and its settings You can change the queue type of the printer or just change the settings After mak ing modifications click OK to return to the main window Click Apply to save the change and restart the printer daemon Depending on which queue type you choose you will see different different options Refer to the app
31. Fri Jan 26 05 13 26 GMT 2001 Build Host porky devel redhat cam Build Date Wed Jan 24 11 59 17 GMT 2001 Distribution Red Hat Linux Vendor Red Hat Inc Group Applications Editors Packager Red Hat Inc Emacs is a powerful customizable self documenting modeless text editor Emacs contains special code editing features a scripting language elisp and the capability to read mail news and more without leaving the editor G fetc skel emacs fusr bin b2m fust bingfemacsclient cy Verify 5 Uninstall X Close Figure 26 9 Query Window The name of the package is centered at the top of the box Below the box is divided into two columns of listed information below this information you will see a display area showing package files In the left column in the information list you will find the size of the file the machine on which the file is found the name of the package distribution and its group In the right column you will find the date that the package was installed on your machine the date the package was built the name of the vendor and the name of the group who packaged the software If the package has not been installed on your machine that space will simply read not installed Below the description is a list of the files contained in the package If a D appears in its related column to the left of the path that file is a documentation file and would be a good thing to read for help on using the application
32. Linux using the mcopy command mcopy ks cfg a Alternatively you can use Windows to copy the file You can also mount the MS DOS boot disk and cp the file over 1 5 2 Making the Kickstart File Available on the Network Network installations using kickstart are quite common because system administrators can easily automate the installation on many networked computers quickly and painlessly In general the approach most commonly used is for the administrator to have both a BOOTP DHCP server and an NFS server on the local network The BOOTP DHCP server is used to give the client system its networking information while the actual files used during the installation are served by the NFS server Often these two servers run on the same physical machine but they are not required to To perform a network based kickstart installation you must have a BOOTP DHCP server on your network and it must include configuration information for the machine on which you are attempting to install Red Hat Linux The BOOTP DHCP server will provide the client with its networking information as well as the location of the kickstart file If a kickstart file is specified by the BOOTP DHCP server the client system will attempt an NFS mount of the file s path and will copy the specified file to the client using it as the kickstart file The exact settings required vary depending on the BOOTP DHCP server you use Here is an example of a line from the dhcpd co
33. Name lt you yourisp net gt sub 1024g E12AF9C4 2000 04 18 B 3 Generating a Revocation Certificate Once you have created your keypair you should create a revocation certificate for your pub lic key If you forget your passphrase or if it has been compromised you can publish this certificate to inform users that your public key should no longer be used ote When you generate a revocation certificate you are not revoking the key you just created Instead you re giving yourself a safe way to revoke your key from public use Let s say you create a key then you forget your passphrase switch ISPs addresses or suffer a hard drive crash The revocation certificate can then be used to disqualify your public key Your signature will be valid to others who read your correspondence before your key is re voked and you will be able to decrypt messages received prior to its revocation To generate a revocation certificate use the gen revoke option gpg output revoke asc gen revoke lt you yourisp net gt Note that if you omit the output revoke asc option from the above your revocation certificate will be returned to the standard output which is your monitor screen While you can copy and paste the contents of the output into a file of your choice using a text editor such as Pico it is probably easier to send the output to a file in your login directory That way you can keep the certificate for use later or move it to a floppy
34. Setup haz haas des 2996 MB 2996 me 15429 M6 Drive devidb Geom 2482 25 63 Model Maxtor 5204913 Drive devmda Geom 2462 25 63 Model Maxtor 52049H3 hab hab 1992 ME fevco me New Edit Delete Reset Make RAID Device star Endl size ae Type Mount Point Format dev hda dev hdal 1 6 47 ext3 boot Yes fdew hdaz 7 366 2996 software RAID devindas 389 770 2998 software RAID fdevindad 771 2482 13429 Extended Lydewhdas 771 2482 13429 ext3 tusr Yes dev hdb dev hdb1 1 254 1992 swap Yes fdev hdb2 255 381 996 ext3 dar Yes 382 2482 1 Figure 5 3 Creating a RAID Array 70 Chapter 5 Software RAID Configuration Network Related References reana Chapter 6 Network Configuration To communicate with other computers computers need a network connection This is ac complished by having the operating system recognize an interface card such as Ethernet ISDN modem or token ring and configuring the interface to connect to the network The Red Hat Network Administration Tool can be used to configure the following types of network interfaces e Ethernet e ISDN e modem e xDSL e token ring CIPE e wireless devices To use the Red Hat Network Administration Tool you must be running the X Window System and have root privileges To start the application use one of the following methods e On the GNOME desktop go to the M
35. The first step for configuring a DHCP client is to make sure the kernel recognizes the network interface card Most cards are recognized during the installation process and the system is configured to use the correct kernel module for the card If you install a card after instal lation Kudzu should recognize it and prompt you to configure the corresponding kernel module for it Be sure to check the Red Hat Linux Hardware Compatibility List available at http hardware redhat com hcl If the network card is not configured by the installation program or Kudzu and you know which kernel module to load for it refer to Chapter 24 for details on loading kernel modules To configure a DHCP client manually you need to modify the etc sysconfig network file to enable networking and the configuration file for each network device in the etc sysconfig network scripts directory In this directory each device should have a configuration file named ifcfg eth0 where eth0 is the network device name The etc sysconfig network file should contain the following line NETWORKING yes You might have more information in this file but the NETWORKING variable must be set to yes if you want networking to start at boot time The etc sysconfig network scripts ifcfg eth0 file should contain the following lines DEVICE eth0 BOOTPROTO dhcp ONBOOT yes You need a configuration file for each device that you want to configure to use DHCP If you prefer a grap
36. The mod_ss1 module is a security module for the Apache Web server The mod_ss1 module uses the tools provided by the OpenSSL Project to add a very important feature to Apache the ability to encrypt communications In contrast using regular HTTP communications between a browser and a Web server are sent in plaintext which could be intercepted and read by someone along the route between the browser and the server This chapter is not meant to be complete and exclusive documentation for any of these pro grams When possible this guide will point you to appropriate places where you can find more in depth documentation on particular subjects This chapter will show you how to install these programs You will also learn the steps necessary to generate a private key and a certificate request how to generate your own self signed certificate and how to install a certificate to use with your secure Web server 14 2 An Overview of Security Related Packages To enable the secure server you need to have the following packages installed at a minimum apache The apache package contains the httpd daemon and related utilities configuration files icons Apache modules man pages and other files used by the Apache Web server mod_ssl The mod_ss1 package includes the mod_ss1 module which provides strong cryptogra phy for the Apache Web server via the Secure Sockets Layer SSL and Transport Layer Security TLS protocols openssl The openssl packa
37. Upgradability Using RPM you can upgrade individual components of your system without com pletely reinstalling When you get a new release of an operating system based on RPM such as Red Hat Linux you don t need to reinstall on your machine as you do with operating systems based on other packaging systems RPM allows intelligent fully automated in place upgrades of your system Configuration files in packages are pre served across upgrades so you won t lose your customizations There are no special upgrade files need to upgrade a package because the same RPM file is used to install and upgrade the package on your system Powerful Querying RPM is designed to provide powerful querying options You can do searches through your entire database for packages or just for certain files You can also easily find out what package a file belongs to and from where the package came The files an RPM package contains are in a compressed archive with a custom binary header containing useful information about the package and its contents allowing you to query individual packages quickly and easily 218 Chapter 25 Package Management with RPM System Verification Another powerful feature is the ability to verify packages If you are worried that you deleted an important file for some package simply verify the package You will be no tified of any anomalies At that point you can reinstall the package if necessary Any configuration files that
38. Window System e make oldconfig This is a non interactive script that will set up your configura tion file to contain the default settings If you are using the default Red Hat Linux kernel it will create a configuration file for the kernel that shipped with Red Hat Linux for your architecture This is useful for setting up your kernel to known work ing defaults and then turning off features that you do not want rote To use kmod see Chapter 24 for details and kernel modules you must answer Yes to kmod support and module version CONFIG_MODVERSIONS support during the configuration 6 After creating a usr src linux 2 4 config file use the command make dep to set up all the dependencies correctly 7 Use the command make clean to prepare the source tree for the build 8 Edit usr src linux 2 4 Makefile so that you do not overwrite your existing kernel The method described here is the easiest to recover from in the event of a mishap If you are interested in other possibilities details can be found at http www redhat com mirrors LDP HOWTO Kernel HOWTO html or in the Makefile in usr src linux 2 4 on your Linux system Edit usr src linux 2 4 Makefile and modify the line beginning with EXTRAVER SION to match a unique name by appending the date to the end of the string For example if you are compiling kernel version 2 4 18 0 12 you can append the flag to Appendix A Building a Custom Kernel 249 look similar to EXTR
39. a button Red Hat Update Agent use the Red Hat Update Agent to download the latest software packages for your system with optional package installation Access to the Red Hat Network website to manage multiple systems downloaded indi vidual packages and schedule actions such as Errata Updates To start using Red Hat Network follow these three basic steps 1 Create a System Profile by running the Red Hat Network Registration Client crhn_register on the system that you want to register 2 Log in to RHN at http rhn redhat com and entitle the system to a service offering Everyone receives a free Red Hat Network account for one system Additional accounts can be purchased 3 Start scheduling updates through the RHN website or download and install Errata Updates with the Red Hat Update Agent For more detailed instructions read the Red Hat Network User Reference Guide available at http www redhat com docs manuals RHNetwork 244 Chapter 27 Red Hat Network Appendixes 3 redhat Appendix A Building a Custom Kernel Many people new to Linux often ask Why should I build my own kernel Given the ad vances that have been made in the use of kernel modules the most accurate response to that question is Unless you already know why you need to build your own kernel you probably do not need to In the past you had to recompile the kernel if you added new hardware on your system In other words the kernel was st
40. a default virtual host as shown in Figure 13 8 Refer to Section 13 3 1 1 1 for details about the default virtual host 128 Chapter 13 Apache Configuration Main Virtual Hosts Server Performance Tuning Virtual Hosts wane o Default Virtual Host _default_ Edit Default Settings oK X Cancel Help Figure 13 8 Virtual Hosts http www apache org docs vhosts and the Apache documentation on your machine provides more information about virtual hosts 13 3 1 Adding and Editing a Virtual Host To add a virtual host click the Virtual Hosts tab and then click the Add button You can also edit a virtual host by selecting it in the list and clicking the Edit button 13 3 1 1 General Options The General Options settings only apply to the virtual host that you are configuring Set the name of the virtual host in the Virtual Host Name text area This name is used by Apache Configuration Tool to distinguish between virtual hosts Set the Document Root Directory value to the directory that contains the root document such as index html for the virtual host This option corresponds to the DocumentRoot di rective within the VirtualHost directive Before Red Hat Linux 7 0 Apache provided with Red Hat Linux used home httpd htm1 as the DocumentRoot In Red Hat Linux 7 3 how ever the default DocumentRoot is var www html The Webmaster email address corresponds to the ServerAdmin directive within the vir tualHo
41. a series of questions about how you use your system and then writes it for you in the file etc sysconfig ipchains You should not try to use GNOME Lokkit to generate complex firewall rules It is intended for average users who want to protect themselves while using a modem cable or DSL In ternet connection To configure specific firewall rules refer to the Firewalling with iptables chapter in the Official Red Hat Linux Reference Guide To disable specific services and deny specific hosts and users refer to Chapter 8 To start GNOME Lokkit type the command gnome lokkit at a shell prompt as root If you do not have the X Window System installed or if you prefer a text based program use the command lokkit to start the text mode version of GNOME Lokkit 88 Chapter 7 Basic Firewall Configuration 7 1 Basic Basic Configuration Lokkit can set up either a low or high security configuration A high security configuration blocks all incoming accesses but requires you use specific ftp configurations and blocks irc dec The lower security option blacks system services but is not so intrusive A High Security more intrusive wv Low Security less intrusive wv Disable Firewall no protection lt Back amp Cancel Figure 7 1 Basic After starting the program choose the appropriate security level for your system High Security This option disables almost all network connects except DNS replies and DHCP so that
42. add a local printer such as one attached to the parallel port or USB port of your computer click the New button in the main printconf window The window shown in Figure 21 2 will appear Click Next to proceed Add A New Print Queue On the following screens you will be asked to provide information for adding a new print queue Nothing will be done to your settings untill you hit Finish on the last screen lt Back gt Next X Cancel Figure 21 2 Adding a Printer You will then see the screen shown in Figure 21 3 Enter a unique name for the printer in the Queue Name text field This can be any descriptive name for your printer The printer name cannot contain spaces and must begin with a letter a through z or A through Z The valid characters are a through z A through zZ 0 through 9 and _ Select Local Printer from the Queue Type menu and click Next Set the Print Queue Name and Type Enter the Queue s name and select the Queue s Type Valid names can contain the characters a z A Z 0 9 and _ They must begin with letters Queue Name test Queue Type Local Printer C Unix Printer C Windows Printer C Novell Printer NCP C JetDirect Printer JETDIRECT MEES D Next X amp Cancel Figure 21 3 Adding a Local Printer printconf attempts to detect your printer device and display it as shown in Figure 21 4 If your printer device is not shown click Custom Device Type the name of
43. and PDF versions of the Official Red Hat Linux manuals are available on the Docu mentation CD and online at http www redhat com docs rote Although this manual reflects the most current information possible you should read the Red Hat Linux Release Notes for information that may not have been available prior to our documentation being finalized They can be found on the Red Hat Linux CD 1 and online at http www redhat com docs manuals linux 1 Changes to This Manual This manual has been expanded to include new features in Red Hat Linux 7 3 as well as topics requested by our readers Changes to this manual include Kickstart Options The kickstart options have been updated to include the new options in Red Hat Linux 7 3 x Introduction Network Configuration This chapter has been written to discussed the revised Red Hat Network Administra tion Tool It is now more task oriented Samba This chapter now includes how to use pam_smbpass to sync users Samba passwords with their system passwords when the passwd command is used Squid Configuration This new chapter discusses the Red Hat Squid Configurator a graphical tool for con figuring the Squid Web Proxy Cache server Mail Transport Agent MTA Configuration This new chapter discusses the Red Hat Mail Transport Agent Switcher application which allows users to select either sendmail or postfix as the default MTA for the system Monitoring Filesystems The Gathering
44. and allow you to choose where to save the file The default file name to save it as is ks cfg After saving the file refer to Section 1 6 for information on how to start the kickstart instal lation 58 Chapter 2 Kickstart Configurator reana Chapter 3 Rescue Mode When things go wrong there are ways to fix problems However these methods require that you understand the system well This chapter describes how to boot into rescue mode and single user mode where you can use your own knowledge to repair the system 3 1 What is Rescue Mode Rescue mode provides the ability to boot a small Linux environment entirely from a diskette CD ROM or using some other method As the name implies rescue mode is provided to rescue you from something During normal operation your Red Hat Linux system uses files located on your system s hard drive to do everything run programs store your files and more However there may be times when you are unable to get Linux running completely enough to access its files on your system s hard drive Using rescue mode you can access the files stored on your system s hard drive even if you cannot actually run Linux from that hard drive Normally you will need to get into rescue mode for one of two reasons e You are unable to boot Linux e You are having hardware or software problems and you want to get a few important files off your system s hard drive Next we take a close
45. cancel the print job in Example 21 1 You must have proper permissions to cancel a print job You can not cancel print jobs that were started by other users unless you are logged in as root on machine to which the printer is attached You can also print a file directly from a shell prompt For example the command lpr sam ple txt will print the text file sample txt The print filter determines what type of file it is and converts it a format the printer can understand 21 11 Configuring the CUPS Printing System CUPS Common UNIX Printing System can be used instead of the default LPRng printing system Some of the advantages of CUPS include 194 Chapter 21 Printer Configuration Support for IPP next generation network printing protocol e Autodetection of network printers e Web interface configuration tool e Support for PPD printer description files e Support for a wide range of printers 21 11 1 Switching Print Systems To use the CUPS printing system instead of LPRng run the redhat switch printer applica tion using one of the following methods On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt redhat switch printer On the KDE desktop go to the Main Menu Button on the Panel gt System gt redhat switch printer e Type the command redhat switch printer at a shell prompt for example in an XTerm or GNOME terminal The program automatically detect if the X Wind
46. change the Start at Boot value of an xinetd service you must click the Save Changes button to restart xinetd and disable enable the xinetd services that you changed To enable a service at boot time for the currently selected runlevel check the checkbox beside the name of the service under the Start at Boot column After configuring the runlevel you must apply the changes Select File gt Save Changes from the pulldown menu or click the Save Changes button warning When you save changes to xinetd services xinetd is restarted When you save changes to other services the runlevel is reconfigured but the changes do not take effect immediately If you check or uncheck the Start at Boot value for a service in etc rc d init d the Save Changes button will become active Click it to reconfigure the currently selected runlevel The changes do not affect the system immediately For example assume you are configuring runlevel 3 If you change the Start at Boot value for the anacron service from checked to unchecked and then click the Save Changes button the runlevel 3 configuration changes so that anacron is not started at boot time However runlevel 3 is not reinitialized so anacron is still running Select one of following options at this point 1 Stop the anacron service Stop the service by selecting it from the list and clicking the Stop the selected service button A message will be displayed stating that the service was stopped su
47. configuration file in Red Hat Linux 7 3 as a starting point and then add your own custom configuration options to it Copy it to its proper location with the command cp usr share doc dhcp lt version number gt dhcpd conf sample etc dhcpd conf where lt version number gt is the DHCP version you are using For a complete list of option statements and what they do refer to the dhcp options man page 12 2 2 Lease Database On the DHCP server the file var 1lib dhcp dhcpd leases stores the DHCP client lease database This file should not be modified by hand DHCP lease information for each re cently assigned IP address is automatically stored in the lease database The information includes the length of the lease to whom the IP address has been assigned the start and end dates for the lease and the MAC address of the network interface card that was used to retrieve the lease All times in the lease database are in Greenwich Mean Time GMT not local time The lease database is recreated from time to time so that it is not too large First all known leases are saved in a temporary lease database The dhcpd leases file is renamed dhcpd leases and the temporary lease database is written to dhcpd leases The DHCP daemon could be killed or the system could crash after the lease database has been renamed to the backup file but before the new file has been written If this happens there is no dhcpd leases file that is required to st
48. description of each service Chapter 8 Controlling Access to Services 95 warning Changes do not take effect immediately after using ntsysv You must stop or start the individual service with the command service daemon stop In the previous example replace daemon with the name of the service you want to stop for example httpd Replace stop with start or restart to start or restart the service If you want to start or stop a service which is managed by xinetd use the command service xinetd restart 8 5 chkconfig The chkconfig command can also be used to activate and deactivate services If you use the chkconfig list command you will see a list of system services and whether they are started on or stopped off in runlevels 0 6 at the end of the list you will see a section for the services managed by xinetd If you use chkconfig list to query a service managed by xinetd you will see whether the xinetd service is enabled on or disabled off For example the following command shows that finger is enabled as an xinetd service chkconfig list finger finger on As shown above if xinetd is running finger is enabled If you use chkconfig list to query a service in etc rc d you will see the service s settings for each runlevel like the following chkconfig list anacron anacron O off Hob api 2 o0n 3 0n 4 on Sron 6 off More importantly chkconfig can be used to set a service to be started or not in a spe
49. disk and store it someplace safe To create a revocation certificate use the command gpg output revoke asc gen revoke lt you yourisp net gt The output will look similar to the following sec 1024D 823D25A9 2000 04 26 Your Name lt you yourisp net gt Create a revocation certificate for this key y You need a passphrase to unlock the secret key for user Your Name lt you yourisp net gt 256 Appendix B Getting Started with Gnu Privacy Guard 1024 bit DSA key ID 823D25A9 created 2000 04 26 ASCII armored output forced Revocation certificate created Once your revocation certificate has been created revoke asc it will be located in your login directory You should copy the certificate to a floppy diskette and store it in a secure place If you don t know how to copy a file to a diskette in Red Hat Linux see the Official Red Hat Linux Getting Started Guide B 4 Exporting your Public Key Before you can use public key cryptography other people must have a copy of your public key To send your key to correspondents or to a keyserver you must export the key To export your key so you can display it on a Web page or paste it in email type the follow ing command gpg armor export lt you yourisp net gt gt mykey asc You will not see any output because not only did you export your public key you redirected the output to a file called for example mykey asc Without the addition of gt mykey asc the
50. drop down box next to Format for saved document choose Text Then you can import the key but remember the name of the file you saved For example if you saved a key as a text file called newkey txt to import the file at a shell prompt type the following command gpg import newkey txt The output will look similar to the following gpg key F78FFE84 public key imported gpg Total number processed 1 gpg imported 1 To check that the process was successful use the gpg list keys command you should see your newly imported key listed on your keyring B 6 What Are Digital Signatures Digital signatures can be compared to your written signature Unlike traditional correspon dence in which it might be possible to tamper with your written signature digital signatures can not be forged That is because the signature is created with your unique secret key and can be verified by your recipient using your public key A digital signature timestamps a document essentially that means that the time you signed the document is part of that signature So if anyone tries to modify the document the ver ification of the signature will fail Some email applications such as Exmh or KDE s KMail include the ability to sign documents with GnuPG within the application s interface Two useful types of digital signatures are clearsigned documents and detached signatures Both types of signatures incorporate the same security of authenticit
51. etc printcap file is dynamically created If you want to add a printer without using printconf edit the etc printcap local file The entries in etc printcap local are not displayed in printconf but are read by the printer daemon If you upgrade your system from a previous version of Red Hat Linux your existing configuration file is converted to the new format used by printconf Each time a new configuration file is generated by printconf the old file is saved as etc printcap old 1 If you type printtool ata shell prompt printconf will start 180 Chapter 21 Printer Configuration File Test Help S H y a New Edit Belgie Default na LOCAL fdev lp0 Ip servername fmachinename sharename queue servername JETDIRECT _ printer example com 9100 Figure 21 1 printconf Five types of print queues can be configured with printconf Local Printer a printer attached directly to your computer through a parallel or USB port In the main printer list as shown in Figure 21 1 the Queue Type for a local printer is set to LOCAL Unix Printer Ipd Spool a printer attached to a different UNIX system that can be accessed over a TCP IP network or example a printer attached to another Red Hat Linux system on your network In the main printer list as shown in Figure 21 1 the Queue Type for a remote UNIX printer is set to LPD Windows Printer SMB a printer attached to a different system which is sharing a printer over a SMB n
52. following options appear below the Queue Type menu as shown in Figure 21 10 Server The hostname or IP address of the NCP system to which the printer is attached e Queue The remote queue for the printer on the NCP system User The name of the user you must log in as to access the printer e Password The password for the user specified in the User field above Configure a Novell Print Queue Configure the remote server and queue of your NCP printer Server User servername username Queue Password ee gt Next amp Cancel Figure 21 10 Choosing the Print Server The next step is to select the type of printer that is connected to the remote NCP system Skip to Section 21 6 to continue Chapter 21 Printer Configuration 187 21 5 Adding a JetDirect Printer To add a JetDirect printer click the New button in the main printconf window The window shown in Figure 21 1 will appear Click Next to proceed You will see the screen shown in Figure 21 11 Enter a unique name for the printer in the Queue Name text field The printer name cannot contain spaces and must begin with a letter a through z or A through Z The valid characters are a through z A through z 0 through 9 and _ Select JetDirect Printer from the Queue Type menu and click Next Set the Print Queue Name and Type Enter the Queue s name and select the Queue s Type Valid names can contain the characters a z A Z 0
53. from a reputable CA guarantees that a website is associated with a particular company or organization Alternatively you can create your own self signed certificate Note however that self signed certificates should not be used in most production environments Self signed certificates will not be automatically accepted by a user s browser the user will be asked by the browser if they want to accept the certificate and create the secure connection See Section 14 5 for more information on the differences between self signed and CA signed certificates Once you have a self signed certificate or a signed certificate from the CA of your choice you will need to install it on your secure Web server 14 4 Using Pre Existing Keys and Certificates If you already have an existing key and certificate for example if you are installing the se cure Web server to replace another company s secure Web server product you will probably be able to use your existing key and certificate with the secure Web server In the following two situations you will not be able to use your existing key and certificate If you are changing your IP address or domain name You can not use your old key and certificate if you are changing your IP address or domain name Certificates are issued for a particular IP address and domain name pair You will need to get a new certificate if you are changing your IP address or domain name If you have a certificat
54. generic generic3 genericps 2 generic3ps 2 genericusb generic3usb geniusnm geniusnmps 2 geniusprops 2 geniusscrollps 2 geniusscrollps 2 thinking thinkingps 2 logitech logitechcc logibm logimman logimmanps 2 logimmant logimmant ps 2 logimmusb microsoft msnew msintelli msintellips 2 msintelliusb msbm mousesystems mmseries mmhittab sun none If the mouse command is given without any arguments or it is omitted the in stallation program will attempt to autodetect the mouse This procedure works for most modern mice Chapter 1 Kickstart Installations 29 1 4 18 network network optional Configures network information for the system If the kickstart installation does not require networking in other words it is not installed over NFS HTTP or FTP net working is not configured for the system If the installation does require networking and network information is not provided in the kickstart file the Red Hat Linux instal lation program assumes that the installation should be done over eth0 via a dynamic IP address BOOTP DHCP and configures the final installed system to determine its IP address dynamically The net work option configures networking information for kick start installations via a network as well as for the installed system bootproto One of dhcp bootp or static defaults to DHCP and dhcp and bootp are treated the same Must be static for static IP information to be used dev
55. is detected properly A 4 Building a Monolithic Kernel To build a monolithic kernel follow the same steps as building a modularized kernel with a few exceptions When configuring the kernel do not compile anything as a module In other words only answer Yes or No to the questions Also you should answer No to kmod support and module version CONFIG_MODVERSIONS support Omit the following steps make modules make modules_install Edit lilo conf to include the line append nomodules or append the kernel line in grub conf with nomodules A 5 Additional Resources For more information on the Linux kernel refer to these resources A 5 1 Installed Documentation e usr src linux 2 4 Documentat ion Advanced documentation on the Linux kernel and its modules These documents are written for people interested in contributing to the kernel source code and understanding how the kernel works A 5 2 Useful Websites http www redhat com mirrors LDP HOWTO Kernel HOWTO html The Linux Kernel HOWTO from the Linux Documentation Project http www kernel org pub linux docs Ikm1 The linux kernel mailing list 2 ae Appendix B Getting Started with Gnu Privacy Guard B 1 An Introduction to GnuPG Have you ever wondered if your email can be read during its transmission from you to other people or from other people to you Unfortunately complete strangers could conceivably intercept or even tamper with your email
56. key Encryption depends upon the use of keys In conventional or symmetric cryptography both ends of the transaction have the same key which they use to decode each other s transmis sions In public key cryptography two keys co exist a public key and a private key A person or an organization keeps their private key a secret and publishes their public key Data en coded with the public key can only be decoded with the private key data encoded with the private key can only be decoded with the public key Oa Remember that your public key can be given to anyone with whom you want to communicate securely but you must never give away your private key For the most part cryptography is beyond the scope of this publication volumes have been written about the subject In this chapter however we hope you will gain enough under standing about GnuPG to begin using cryptography in your own correspondence For more information about GnuPG including an online users guide visit http www gnupg org If you want to learn more about GnuPG PGP and encryption technology see Section B 7 254 Appendix B Getting Started with Gnu Privacy Guard B 2 Generating a Keypair To begin using GnuPG you must first generate a new keypair a public key and a private key To generate a keypair at a shell prompt type the following command gpg gen key Since you work with your user account most frequently you should perform this action while l
57. kickstart how the file is found 40 Kickstart Configurator 43 kickstart file include 38 auth 19 authconfig 19 autostep 19 bootloader 21 clearpart 22 creating 18 device 23 23 263 deviceprobe 23 diskette based 39 driverdisk 23 firewall 23 format of 18 include contents of another file 38 install 24 installation methods 24 interactive 26 keyboard 26 lang 26 langsupport 27 lilo 27 lilocheck 28 mouse 28 network 29 network based 39 options 18 package selection specification 35 part 30 partition 30 post installation configuration 37 pre installation configuration 37 raid 32 reboot 33 rootpw 33 skipx 33 text 34 timezone 34 upgrade 34 what it looks like 18 xconfig 34 zerombr 35 kickstart installations 17 diskette based 39 file format 18 file locations 39 network based 39 starting 40 kmod 211 ksconfig See Kickstart Configurator L loading kernel modules 211 Ipd 180 LPRng 179 Ismod 211 lspci 176 264 Mail Transport Agent See MTA Maximum RPM 227 memory usage 173 modem connection See network configuration modprobe 212 modules conf 211 monitoring filesystems 175 mounting NFS filesystems 103 MTA Red Hat Mail Transport Agent Switcher 155 setting default 155 mtools and the floppy group 162 N named conf 149 neat See network configuration netcfg See network configuration network configuration CIPE connection 81 activa
58. lt id gt The partition will be used for software RAID see the Section 1 4 20 below 8128 oa Ze gt The minimum partition size in megabytes Specify an integer value here such as 500 Do not append the number with MB grow Tells the partition to grow to fill available space if any or up to the maximum size setting maxsize lt size gt The maximum partition size in megabytes when the partition is set to grow Specify an integer value here and do not append the number with MB noformat Tells the installation program not to format the partition for use with the onpart command onpart lt part gt oOr usepart lt part gt Tells the installation program to put the partition on the already existing device lt part gt For example partition home onpart hdal will put home on dev ndal which must already exist If you use onpart you still must specify a size with size for the file to be parsed correctly The size will be ignored since the partition already exists ondisk lt disk gt or ondrive lt drive gt Forces the partition to be created on a particular disk For example ondisk sdb will put the partition on the second disk on the system asprimary Forces automatic allocation of the partition as a primary partition or the partition ing will fail bytes per inode lt N gt lt N gt represents the number of bytes per inode on the filesystem when it is created It must be given in decimal for
59. message linear default linux image boot vmlinuz 2 4 18 0 12 label linux initrd initrd 2 4 18 0 12 img read only root dev hda5 The kernel RPM package activates the changes by running the command sbin 1lilo It is a good idea to run it again otherwise the system will not boot the new kernel After running it you will see output similar to the following Added linux The after Linux means that the section labeled 1inux is the default kernel that LILO will boot You can begin testing your new kernel by rebooting your computer and watching the mes sages to ensure your hardware is detected properly 210 Chapter 23 Ugrading the Kernel redhat Chapter 24 Kernel Modules The Linux kernel has a modular design At boot time only a minimal resident kernel is loaded into memory Thereafter whenever a user requests a feature that is not present in the resident kernel a kernel module is dynamically loaded into memory After a specified period of inactivity the module may be removed from memory The mechanism that supports dynamic loading of modules is a kernel thread called kmod Modules are not loaded unless they are needed When the kernel requests a module the module is loaded along with all its module dependencies Red Hat Linux also includes a cron task that removes all unused modules every ten min utes The cron task is located in the file etc cron d kmod Refer to Section 22 1 for more information on cron task
60. network interfaces can be activated IRC ICQ and other instant messaging services as well as RealAudio will not work without a proxy Low Security This option will not allow remote connections to the system including NFS connections and remote X Window System sessions Services that run below port 1023 will not accept connections including FTP SSH Telnet and HTTP Disable Firewall This option does not create any security rules It is recommended that this option only be chosen if the system is on a trusted network not on the Internet if the system is behind a larger firewall or if you write your own custom firewall rules If you choose this option and click Next proceed to Section 7 5 The security of your system will not be changed 7 2 Local Hosts If there are Ethernet devices on the system the Local Hosts page allows you to configure whether the firewall rules apply to connection requests sent to each device If the device connects the system to a local area network behind a firewall and does not connect directly to the Internet select Yes If the Ethernet card connects the system to a cable or DSL modem it is recommended that you select No Chapter 7 Basic Firewall Configuration Local Hosts Figure 7 2 Local Hosts 7 3 DHCP You seem to have an ethernet eth0 attached to your machine Shall trust the hosts that are connected via this card If this connection is your link to the internet e
61. normally be asked during a typical Red Hat Linux installation Kickstart files can be kept on single server system and read by individual computers dur ing the installation This installation method can support the use of a single kickstart file to install Red Hat Linux on multiple machines making it ideal for network and system admin istrators Kickstart lets you automate most of a Red Hat Linux installation including Language selection Mouse configuration Keyboard selection Boot loader installation Disk partitioning Network configuration NIS LDAP Kerberos Hesiod and Samba authentication Firewall configuration Package selection X Window System configuration 1 2 How Do You Perform a Kickstart Installation Kickstart installations can be performed using a local CD ROM a local hard drive or via NFS FTP or HTTP To use kickstart you must 1 Create a kickstart file 2 Create a boot disk with the kickstart file or make the kickstart file available on the network 3 Start the kickstart installation This chapter explains these steps in detail 18 Chapter 1 Kickstart Installations 1 3 Creating the Kickstart File The kickstart file is a simple text file containing a list of items each identified by a keyword You can create it by editing a copy of the sample ks file found in the RH Docs directory of the Red Hat Linux Documentation CD using the Kickstart Configurator application or writi
62. of a software based array is dependent on the server CPU performance and load For information on configuring Software RAID in the Red Hat Linux installation program refer to the Chapter 5 For those interested in learning more about what Software RAID has to offer here is a brief list of the most important features Threaded rebuild process Fully kernel based configuration e Portability of arrays between Linux machines without reconstruction e Backgrounded array reconstruction using idle system resources e Hot swappable drive support e Automatic CPU detection to take advantage of certain CPU optimizations 4 4 RAID Levels and Linear Support RAID supports various configurations including levels 0 1 4 5 and linear These RAID types are defined as follows Level 0 RAID level 0 often called striping is a performance oriented striped data mapping technique This means the data being written to the array is broken down into strips and written across the member disks of the array allowing high I O performance at low inherent cost but provides no redundancy The storage capacity of a level 0 array is equal to the total capacity of the member disks in a Hardware RAID or the total capacity of member partitions in a Software RAID e Level 1 RAID level 1 or mirroring has been used longer than any other form of RAID Level 1 provides redundancy by writing identical data to each member disk of the array leaving a m
63. provide correct information for all of the fields but especially for the organization Name and the Common Name CAs check the information provided in the CSR to determine whether your organization is re sponsible for what you provided as the Common Name CAs will reject CSRs which include information they perceive as invalid e For Common Name make sure you type in the real name of your secure Web server a valid DNS name and not any aliases which the server may have e The Email Address should be the email address for the webmaster or system administra tor e Avoid any special characters like amp etc Some CAs will reject a certificate request which contains a special character So if your company name includes an ampersand amp spell it out as and instead of amp Chapter 14 Apache Secure Server Configuration 145 Do not use either of the extra attributes A challenge passwordand An optional com pany name To continue without entering these fields just press Enter to accept the blank default for both inputs When you have finished entering your information a file named server csr will be created This file is your certificate request ready to send to your CA After you have decided on a CA follow the instructions they provide on their website Their instructions will tell you how to send your certificate request any other documentation that they require and your payment to them After you have f
64. sbin bin usr sbin usr bin MAILTO root HOME run parts 01 root run parts etc cron hourly 02 4 root run parts etc cron daily 22 4 0 root run parts etc cron weekly 42 4 1 root run parts etc cron monthly The first four lines are variables used to configure the environment in which the cron tasks are run The value of the SHELL variable tells the system which shell environment to use in this example the bash shell and the PATH variable defines the path used to execute com mands The output of the cron tasks are emailed to the username defined with the MAILTO variable If the MAILTO variable is defined as an empty string MAILTO email will not be sent The HOME variable can be used to set the home directory to use when executing commands or scripts Each line in the etc crontab file represents a task and has the format minute hour day month dayofweek command 198 Chapter 22 Automated Tasks e minute any integer from 0 to 59 e hour any integer from 0 to 23 e day any integer from 1 to 31 must be a valid day if a month is specified month any integer from 1 to 12 or the short name of the month such as jan feb and so on e dayofweek any integer from 0 to 7 where 0 or 7 represents Sunday or the short name of the week such as sun mon and so on e command the command to execute The command can either be a command such as 1s proc gt gt tmp proc or the command to e
65. size C Fill all space up to MB an Fill to maximum allowable size I Force to be a primary partition asprimary Make partition on specific drive andisk I Use existing partition anpart Panttior __ F Format partition Bow amp Cancel Figure 2 5 Creating Partitions To edit an existing partition select the partition from the list and click the Edit button The same Partitions Options window that appears when you add a partition appears except it contains the values for the selected partition Modify the partition options and click OK To delete an existing partition select the partition from the list and click the Delete button 48 Chapter 2 Kickstart Configurator 2 5 Network Configuration File Help Network Configuration Basic Configuration Boot Loader Options Installation Method Network Type DHCP C Static IP C None Partition Information Network Configuration Authentication Firewall Configuration X Configuration IP Address Packi Selecti pre nsaiaton Sgt Nemask J Post Installation Script GEWAN m fe olen Name Server Save File X Cancel Help Figure 2 6 Network Configuration There are three network configuration options DHCP Static IP and None If there is not an Ethernet card in the system choose None Networking is only required if you choose a networking type installation method NFS or FTP If
66. that is providing the Web pages to the browser If your secure server is being accessed by the public at large your secure Web server needs a certificate signed by a CA so that people who visit your website can rely that the website is owned by the organization who claims to own it Before signing a certificate a CA verifies that the organization requesting the certificate was actually who they claimed to be Most Web browsers that support SSL have a list of CAs whose certificates they will automat ically accept If a browser encounters a certificate whose authorizing CA is not in the list the browser will ask the user to choose whether to accept or decline the connection You can generate a self signed certificate for your secure Web server but be aware that a self signed certificate will not provide the same functionality as a CA signed certificate A self signed certificate will not be automatically recognized by users browsers and a self signed certificate does not provide any guarantee concerning the identity of the organization that is providing the website A CA signed certificate provides both of these important capabilities for a secure server If your secure server will be used in a production environment you will probably need a CA signed certificate The process of getting a certificate from a CA is fairly easy A quick overview is as follows 1 Create an encryption private and public key pair 2 Create a certificate re
67. the boot file provided by DHCP is looked for in the kickstart directory on the NFS server If DHCP did not specify a bootfile then the installation program tries to read the file kickstart 1 2 3 4 kickstart where 1 2 3 4 is the numeric IP address of the machine being installed ksdevice lt device gt The installation program will use this network device to connect to the network For example to start a kickstart installation with the kickstart file on an NFS server that is connected to the system through the eth1 device use the command ks nfs lt server gt lt path gt ksdevice eth1 at the boot prompt 42 Chapter 1 Kickstart Installations redhat Chapter 2 Kickstart Configurator Kickstart Configurator allows you to create a kickstart file using a graphical user interface so that you do not have to remember the correct syntax of the file After choosing the kick start options click the Save File button verify the options you have chosen and save the kickstart file to a desired location To use Kickstart Configurator you must by running the X Window System To start Kick start Configurator use one of the following methods e On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt Kickstart Configurator On the KDE desktop go to the Main Menu Button on the Panel gt System gt Kickstart Configurator e Type the command usr sbin ksconfig at a shell prompt
68. the disk label to the default for your architecture msdos for x86 and gpt for Itanium It is useful so that the installation program does not ask if it should initialize the disk label if installing to a brand new hard drive ote If the clearpart command then the onpart command cannot be used on a logical partition 1 This option is new to Red Hat Linux 7 3 Chapter 1 Kickstart Installations 23 1 4 5 device device optional On most PCI systems the installation program will autoprobe for Ethernet and SCSI cards properly On older systems and some PCI systems however kickstart needs a hint to find the proper devices The device command which tells Anaconda to install extra modules is in this format device lt type gt lt moduleName gt opts lt options gt lt type gt should be scesi or eth and lt moduleName gt is the name of the kernel mod ule which should be installed opts Options to pass to the kernel module Note that multiple options may be passed if they are put in quotes For example opts aicl52x 0x340 io 11 1 4 6 deviceprobe deviceprobe optional Forces a probe of the PCI bus and loads modules for all the devices found if a module is available 1 4 7 driverdisk driverdisk optional Driver disks can be used during kickstart installations You will need to copy the driver disk s contents to the root directory of a partition on the system s hard drive Then you will need
69. through ssh select this option Telnet Telnet allows you to log into your machine remotely however it is not secure It sends plain text including passwords over the network It is recommended that you use SSH to log into your machine remotely If you are required to have telnet access to your system select this option To disable other services that you do not need use Serviceconf see Section 8 3 or ntsysv see Section 8 4 or chkconfig see Section 8 5 7 5 Activating the Firewall Clicking Finish on the Activate the Firewall page will write the firewall rules to etc sysconfig ipchains and start the firewall by starting the ipchains service It is highly recommended that you run GNOME Lokkit from the machine not from a remote X session If you disable remote access to your system you will no longer be able to access it or disable the firewall rules Click Cancel if you do not want to write the firewall rules 7 5 1 Mail Relay A mail relay is a system that allows other systems to send email through it If your system is a mail relay someone can possibly use it to spam others from your machine If you chose to enable mail services after you click Finish on the Activate the Firewall page you will be prompted to check for mail relay If you choose Yes to check for mail re lay GNOME Lokkit will attempt to connect to the Mail Abuse Prevention System website at http www mail abuse org and run a mail relay test pr
70. to allow UDP packets on port 1234 through specify 1234 udp To specify multiple ports sepa rate them by commas 1 4 9 install install optional Tells the system to install a fresh system rather than upgrade an existing system This is the default mode 1 4 10 Installation Methods You must use one of these four commands to specify what type of kickstart installation is being performed Chapter 1 Kickstart Installations 25 nfs Install from the NFS server specified server lt server gt Server from which to install hostname or IP e dir lt dir gt Directory containing the Red Hat installation tree For example nfs server lt server gt dir lt dir gt cdrom Install from the first CD ROM drive on the system For example cdrom harddrive url Install from a Red Hat installation tree on a local drive which must be either vfat or ext2 e partition lt partition gt Partition to install from such as sdb2 e dir lt dir gt Directory containing the Red Hat installation tree For example harddrive partition lt partition gt dir lt dir gt Install from a Red Hat installation tree on a remote server via FTP or HTTP For example url url http lt server gt lt dir gt url url ftp lt username gt lt password gt lt server gt lt dir gt 26 Chapter 1 Kickstart Installations 1 4 11 interactive interact ive optional Uses the information provi
71. user configuration and group config uration redhat switch printer 194 redhat switchmail 155 rescue mode 59 definition of 59 from CD diskette 59 using 59 utilities available 61 rmmod 212 RPM 217 additional resources 227 book about 227 checking package signatures 223 dependencies 219 design goals 217 determining file ownership with 225 documentation with 225 file conflicts resolving 219 finding deleted files with 225 freshen 221 freshening packages 221 GnuPG 223 installing 218 md5sum 223 preserving configuration files 220 querying 221 querying for file list 226 querying uninstalled packages 226 tips 225 uninstalling 220 upgrading 220 using 218 verifying 222 website 227 runlevels 91 266 S Samba 107 additional resources 110 configuration 107 smb conf 107 encrypted passwords 108 pam_smbpass 108 reasons for using 107 share connecting to 109 connecting to with Nautilus 109 syncing passwords with passwd 108 with Windows 2000 108 with Windows NT 4 0 108 scp See OpenSSH secure server accessing 147 books 148 connecting to 147 documentation installed 148 explanation of security 139 finding help with 148 installing 137 key generating 142 problems during installation 148 providing a certificate for 139 URLs for 147 websites 148 security 91 explanation of 139 Serviceconf 93 services controlling access to 91 sftp See OpenSSH shutdown dis
72. username and password to use the printer should be different from the username and password used for the user s account on the local Red Hat Linux system If they are different then the only possible security compromise would be unauthorized use of the printer If there are file shares from the SMB server it is recommended that they also use a different password than the one for the print queue 21 4 Adding a Novell NetWare NCP Printer To add a Novell NetWare NCP printer click the New button in the main printconf window The window shown in Figure 21 1 will appear Click Next to proceed You will see the screen shown in Figure 21 9 Enter a unique name for the printer in the Queue Name text field The printer name cannot contain spaces and must begin with a letter a through z or A through Z The valid characters are a through z A through zZ 0 through 9 and _ Select Novell Printer from the Queue Type menu and click Next 186 Chapter 21 Printer Configuration Set the Print Queue Name and Type Enter the Queue s name and select the Queue s Type Valid names can contain the characters a z A Z 0 9 and _ They must begin with letters Queue Name testa Queue Type C Local Printer LOCAL C Unix Printer LPD C Windows Printer SMB Novell Printer NCP C JetDirect Printer JETDIRECT lt Back gt Next X amp Cancel j Figure 21 9 Adding an NCP Printer Text fields for the
73. warning The mount point directory on local machine mnt loca1 in the above example must exist In this command shadowman example com is the hostname of the NFS fileserver mnt export is the filesystem that shadowman is exporting and mnt 1ocal is the location to mount the filesystem on the local machine After the mount command runs and if the client has proper permissions from the shadowman example com NFS server the client user can execute the command 1s mnt local to display a listing of the files in mnt export On shadowman example com 10 2 1 Mounting NFS Filesystems using etc fstab An alternate way to mount an NFS share from another machine is to add a line to the etc fstab file The line must state the hostname of the NFS server the directory on the server being exported and the directory on the local machine where the NFS share is to be mounted You must be root to modify the etc fstab file The general syntax for the line in etc fstab is as follows server usr local pub pub nfs rsize 8192 wsize 8192 timeo 14 intr The mount point pub must exist on the client machine After adding this line to etc fstab on the client system type the command mount pub ata shell prompt and the mount point pub will be mounted from the server 104 Chapter 10 Network File System NFS 10 2 2 Mounting NFS Filesystems using autofs A third option for mounting an NFS share is the use of autofs Autofs uses the automount daemon t
74. webmaster and directed to the website s domain should reach the appropriate person For example if you experienced problems while visiting www example com you should send e mail to webmaster example com al Figure 14 1 The Default Home Page 14 10 Accessing Your Secure Server To access your secure server use a URL like this https your_domain Note that URLs which are intended to connect to your secure Web server should begin with the https protocol designator instead of the more common http protocol designator Your non secure server can be accessed using an URL like this http your_domain The standard port for secure Web communications is port 443 The standard port for non secure Web communications is port 80 The secure Web server default configuration listens on both of the two standard ports Therefore you will not need to specify the port number in a URL the port number is assumed However if you configure your server to listen on a non standard port i e anything besides 80 or 443 you will need to specify the port number in every URL which is intended to connect to the server on the non standard port For example you may have configured your server so that you have a virtual host running non secured on port 12331 Any URLs intended to connect to that virtual host must specify the port number in the URL The following URL example will attempt to connect to a non secure Web server listening
75. whole All of the individual connections made to look up each hostname add up Therefore for your own Web server s benefit as well as for the Internet s benefit you should leave this option set to No Reverse Lookup 13 2 3 Environment Variables Apache can use the mod_env module to configure the environment variables which are passed to CGI scripts and SSI pages Use the Environment Variables page to configure the directives for this Apache module Chapter 13 Apache Configuration 125 Site Configuration Set for CGI Scripts Logging Environment Variables Directories Delete Pass to CGI Scripts Unset for CGI Scripts Detete 0K Cancel Help Figure 13 5 Environment Variables Use the Set for CGI Scripts section to set an environment variable that is passed to CGI scripts and SSI pages For example to set the environment variable MAXNuM to 50 click the Add button inside the Set for CGI Script section as shown in Section 13 2 3 and type MAXNUM in the Environment Variable text field and 50 in the Value to set text field Click OK The Set for CGI Scripts section configures the Set Env directive Use the Pass to CGI Scripts section to pass the value of an environment variable when Apache was first started to CGI scripts To see this environment variable type the command env at a shell prompt Click the Add button inside the Pass to CGI Scripts section and enter the name of the environment variable in the resulting dia
76. you are unsure which to choose choose None Networking can always be configured after installation with the Red Hat Network Configurator using the command redhat config network If you select Static IP you must provide additional networking information in the table below the network types Chapter 2 Kickstart Configurator 2 6 Authentication File Help Authentication Configuration Basic Configuration Boot Loader Options Authentication 7 Use Shadow Passwords 7 Use MDS Installation Method Partition Information Network Configuration Authentication Firewall Configuration NIS LDAP Kerberos 5 Hesiod SMe Name Switch Cache NIS Authentication X Configuration Jenene NS Package Selection NIS Domain J Pre Installation Script ci Post Installation Script Use broadcast to find NIS server NIS Server X Cancel Help Save File Figure 2 7 Authentication 49 In the Authentication section select whether to use shadow passwords and md5 encryption for user passwords These options are highly recommended and chosen by default The Authentication Configuration options allows you to configure the following methods of authentication NIS LDAP e Kerberos 5 Hesiod e SMB e Name Switch Cache They are not enabled by default To enable one or more of these methods click the appropri ate tab click the checkbutton next to Enable and enter the appropriat
77. you modified are preserved during reinstallation Pristine Sources A crucial design goal was to allow the use of pristine software sources as distributed by the original authors of the software With RPM you have the pristine sources along with any patches that were used plus complete build instructions This is an important advantage for several reasons For instance if a new version of a program comes out you do not necessarily have to start from scratch to get it to compile You can look at the patch to see what you might need to do All the compiled in defaults and all of the changes that were made to get the software to build properly are easily visible using this technique The goal of keeping sources pristine may only seem important for developers but it results in higher quality software for end users too We would like to thank the folks from the BOGUS distribution for originating the pristine source concept 25 2 Using RPM RPM has five basic modes of operation not counting package building installing uninstalling upgrading querying and verifying This section contains an overview of each mode For complete details and options try rpm help or turn to Section 25 5 for more information on RPM 25 2 1 Finding RPM Packages Before using an RPM you must know where to find them An Internet search will return many RPM repositories but if you are looking for RPM packages built by Red Hat they can be found at the fo
78. your printer 182 Chapter 21 Printer Configuration device and click OK to add it to the printer device list A printer device attached to the parallel port is usually referred to as dev 1p0 A printer device attached to the USB port is usually referred to as dev usb1p0 After selecting your printer device click Next Configure a Local Printer Select the printer device to use or use the custom option if it is not listed Device Rescan Devices Custom Device gt Next X amp Cancel Figure 21 4 Local Printer Device Next printconf will try to detect which printer is attached to the printer device Skip to Section 21 6 to continue 21 2 Adding a Remote UNIX Printer To add a remote UNIX printer such as one attached to a different Linux system on the same network click the New button in the main printconf window The window shown in Figure 21 2 will appear Click Next to proceed You will then see the screen shown in Figure 21 5 Enter a unique name for the printer in the Queue Name text field The printer name cannot contain spaces and must begin with a letter a through z or A through Z The valid characters are a through z A through zZ 0 through 9 and _ Select Unix Printer from the Queue Type menu and click Next Chapter 21 Printer Configuration 183 Set the Print Queue Name and Type Enter the Queue s name and select the Queue s Type Valid names can contain the characters a z A Z
79. 3584 S 16 52s sawfish root 364 356 S 13 39s gpm tfox 6292 6292 S 13 15s panel root 544 544 6 49s init tfox 4416 4416 6 33s tasklist_applet tfox 3932 3932 S 5 89s deskguide_applet tfox 21132 21132 S 5 45s gimp tfox 1840 1840 5 4 59s xscreensaver xfs 5532 4780 5 4 52s xfs tfox 4244 4244 2 288 gnome terminal tfox 4096 4096 1 46s gnome terminal tfox 2124 2124 1 43s gnome smproxy foofy chinfox CPU 8 37 user 7 57 system 5 44pm up 2 days loadavg 0 08 0 15 0 25 MOD oOWMON BRR WOOON ONE 9 0 0 0 0 0 1 0 0 0 0 0 3 1 0 0 0 0 SRR RPOMRRONOENOOBTHEE Figure 20 1 GNOME System Monitor Chapter 20 Gathering System Information 173 20 2 Memory Usage The free command displays the total amount of physical memory and swap space for the system as well as the amount of memory that are used free shared in kernel buffers and cached total used free shared buffers cached Mem 256812 240668 16144 105176 50520 81848 buffers cache 108300 148512 Swap 265032 780 264252 The command free mshows the same information in megabytes which are easier to read total used free shared buffers cached Mem 250 235 15 102 49 719 buffers cache 105 145 Swap 258 0 258 If you would like to use a graphical interface with free you can use the GNOME System Monitor To start it on the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt System Monitor or type
80. 4 18 0 12 1386 rpm rpm Uvh kernel docs 2 4 18 0 12 i386 rpm rpm Uvh kernel utils 2 4 18 0 12 1386 rpm 208 Chapter 23 Ugrading the Kernel If you are using PCMCIA for example a laptop you also need to install the kernel pemcia cs and keep the old version If you use the i switch it will probably return a conflict because the older kernel needs this package to boot with PCMCIA support To work around this use the force switch as follows the version might vary rpm ivh force kernel pcmcia cs 3 1 24 2 1386 rpm If you are using the ext3 file system or a SCSI controller you need an initial RAM disk The purpose of the initial RAM disk is to allow a modular kernel to have access to modules that it might need to boot from before the kernel has access to the device where the modules normally reside The initial RAM disk is created by using the mkinitrd command However the Red Hat kernel RPM package performs this step for you To verify that it was created use the com mand 1s 1 boot You should see the file initrd 2 4 18 0 12 img the version should match the version of the kernel you just installed Now that you have installed the new kernel you need to configure the boot loader to boot the new kernel Refer to Section 23 5 for details 23 5 Configuring the Boot Loader The kernel RPM package configures the GRUB or LILO boot loader to boot the newly in stalled kernel if either boot loader is installed However it is alwa
81. 7 xDSL Settings 5 If the Select Ethernet Adapter window appears select the manufacturer and model of the Ethernet card Select the device name If this is the system s first Ethernet card select eth0 as the device name if this is the second Ethernet card select eth1 and so on The Network Administration Tool also allows you to configure the resources for the NIC Click Next to continue 6 Enter the Provider Name Login Name and Password 7 Click Next 8 On the Create DSL Connection page click Finish After configuring the DSL connect it appears in the device list as shown in Figure 6 6 Devices Hardware Hosts ONS You may configure network devices associated Fi 2 with physical hardware here Multiple logical 1 devices can be associated with a single piece i of hardware Status Device Nickname Type Add Edit Copy Delete Activate Deactivate Monitor Help y Apply X Close Figure 6 8 xDSL Device Be sure to click Apply to save the changes After adding the xDSL connection you can edit its configuration by selecting the device from the device list and clicking Edit For example when the device is added it is configured not to start at boot time by default Edit its configuration to modify this setting When the device is added it is not activated as seen by its Inactive status To activate the device select it from the device list and click the Activate bu
82. ADSL IDSL and SDSL Network Administration Tool uses the term xDSL to mean all types of DSL connections Some DSL providers require you to configure your system to obtain an IP address through DHCP with an Ethernet card Some DSL providers require you to configure a PPPoE Point to Point Protocol over Ethernet connection with an Ethernet card Ask your DSL provider which method to use If you are required to use DHCP refer to Section 6 2 to configure your Ethernet card If you are required to use PPPoE follow these steps 1 Click the Devices tab 2 Click the Add button 3 Select xDSL connection from the Device Type list and click Next 4 If your Ethernet card is already in the hardware list select the Ethernet Device from the pull down menu from the page shown in Figure 6 7 Otherwise the Select Ethernet Adapter window appears rote The installation program usually detects supported Ethernet devices and prompts you to con figure them If you configured any Ethernet devices during the installation they will already appear in the hardware list on the Hardware tab Chapter 6 Network Configuration 79 Configure DSL connection Select the ethemet device for this account Ethernet Device eth0 Intel EtherExpress Pre Enter the provider name for this account Provider Name Enter the login name for this account Login Name Enter the password for this account Password lt Back X Cancel Figure 6
83. AVERSION 0 1 21 ju12001 This will allow you to have the old working kernel and the new kernel version 2 4 18 0 12 jul2001 on your system at the same time 9 Build the kernel with make bzImage 10 Build any modules you configured with make modules 11 Use the command make modules_instal11 to install the kernel modules even if you did not build any Make sure that you type the underscore _ This will install the ker nel modules into the directory path 1ib modules KERNELVERSION kernel drivers where KERNELVERSION is the version specified in the Makefile In the example it would be lib modules 2 4 18 0 12 4ju12001 kernel drivers 12 If you have a SCSI adapter and you made your SCSI driver modular build a new initrdimage Also if you build your kernel with ext3 support as a module the default in Red Hat Linux you must create an initrd image Refer to Section A 2 for details 13 Use make install to copy your new kernel and its associated files to the proper direc tories 14 The kernel is built and installed now The next step is configuring the boot loader to boot the new kernel Refer to Section A 3 for more information A 2 Making an initrd Image An initrd image is needed for loading your SCSI module at boot time or if you are compil ing the kernel with ext3 support as a module If you do not need an initrd image do not make one and do not edit 1ilo conf or grub conf to include this image Use the sbin mkinitrd
84. DHCP daemon Efon Do not perform routine tasks as root use a regular user account unless you need to use the root account for system administration tasks warning If you choose not to partition manually a server installation will remove all existing partitions on all installed hard drives Do not choose this installation class unless you are sure you have no data you need to save 3 More to Come The Official Red Hat Linux Customization Guide is part of Red Hat s growing commitment to provide useful and timely support to Red Hat Linux users As new tools and applications are released this guide will be expanded to include them xiv Introduction 3 1 Send in Your Feedback If you spot a typo in the Official Red Hat Linux Customization Guide or if you have thought of a way to make this manual better we would love to hear from you Please submit a report in Bugzilla http www redhat com bugzilla against the component rhl cg Be sure to mention the manual s identifier rhl cg EN 7 3 HTML RHI 2002 04 05T14 34 0400 By mentioning this manual s identifier we will know exactly which version of the guide you have If you have a suggestion for improving the documentation try to be as specific as possible If you have found an error please include the section number and some of the surrounding text so we can find it easily 4 Sign Up for Support If you have an official edition of Red Hat Linux 7 3 please r
85. Help Boot Loader Options F Install Boot Loader Partition Information Network Configuration Choose Boot Loader GRUB C LILO Authentication Firewall Configuration Install Boot Loader on MBR C First sector of boot partition X Configuration Kernel parameters Package Selection Pre Installation Script Post Installation Script LILO F Use its Force use of Iba32 mode GRUB Options Use GRUB Password Encrypt GRUB password Save File X Cancel Help Figure 2 2 Boot Loader Options You have the option of installing GRUB or LILO as the boot loader If you do not want to install a boot loader uncheck Install Boot Loader If you choose not to install a boot loader make sure you create a boot disk or have another way to boot such as a third party boot loader your Red Hat Linux system Chapter 2 Kickstart Configurator 45 If you choose to install a boot loader you must also choose which boot loader to install GRUB or LILO and where to to install the boot loader the Master Boot Record or the first sector of the boot partition Install the boot loader on the MBR if you plan to use it as your boot loader If you are using a different boot loader install LILO or GRUB on the first sector of the boot partition and configure the other boot loader to boot Red Hat Linux If you need to pass any special parameters to the kernel to be used when the system boots enter them in the Kernel parameters text fiel
86. If a c appears in its respective column the file is a configuration file Under the s column you can view the state of the package here you will see if any files are missing from the package this probably means that there is a problem with the package If you are querying a package that is already installed you will also find two additional buttons at the bottom of this window Verify and Uninstall If you are performing a query on a package that has not been installed yet the buttons on the bottom will be labeled Install Upgrade and Check Sig To close the query window without performing any action left click on the X at the top right of the window bar 26 5 2 Verifying Packages Verifying a package checks all of the files in the package to ensure they match the ones present on your system The checksum file size permissions and owner attributes are all checked against the database This check can be used when you suspect that one of the program s files has become corrupted for some reason Choosing the packages to verify is like choosing the packages to query Select the packages in the display window and use the Verify button on the toolbar or from Packages gt Verify on the menu A window opens like the one in Figure 26 10 240 Chapter 26 Gnome RPM emacs 20 7 30 No problems found Package File Problem Figure 26 10 Verify Window As the package is being checked you will see the progress in the Verify w
87. O O O l Confirm Password a Home Directory nomefsmith Login Shell einas o YC Pox X Cancel Figure 19 3 User Properties The User Properties window is divided into tabbed pages e User Data Basic user information configured when you added the user Use this tab to change the user s full name password home directory or login shell Account Info Select Enable account expiration if you want the account to expire on a certain date Enter the date in the provided fields Select User account is locked to lock the user account so that the user can not log in to the system Password Info This tab shows the date that the user lasted changed his password To force the user to change his password after a certain number of days select Enable pass word expiration You can also set the number of days before the user is allowed to change his password the number of days before the user is warned to change his password and days before the account become inactive e Groups Select the groups that you want the user to be a member of and the user s primary group 19 3 Adding a New Group To add a new user group click the New Group button A window similar to Figure 19 4 will appear Type the name of the new group to create To specify a group ID for the new group select Specify group ID manually and select the GID Red Hat Linux reserves group IDs lower than 500 for system groups Click OK to create the group The new g
88. PUT request and how long it will wait between ACKs responding to TCP packets By default Connection Timeout is set to 300 seconds which is appropriate for most situations This option corresponds to the TimeOut directive Set the Max requests per connection to the maximum number of requests allowed per per sistent connection The default value is 100 which should be appropriate for most situations This option corresponds to the MaxRequest sPerChild directive If you check the Allow unlimited requests per connection option the MaxKeepAliveRequests directive to 0 and unlimited requests are allowed If you uncheck the Allow Persistent Connections option the KeepAlive directive is set to false If you check it the KeepAlive directive is set to true and the KeepAliveTimeout directive is set to the number that is selected as the Timeout for next Connection value This directive sets the number of seconds your server will wait for a subsequent request after a Chapter 13 Apache Configuration 135 request has been served before it closes the connection Once a request has been received the Connection Timeout value applies instead Setting the Persistent Connections to a high value may cause a server to slow down de pending on how many users are trying to connect to it The higher the number the more server processes waiting for another connection from the last client that connected to it 13 6 Saving Your Settings If you do not want
89. Red Hat Linux 7 3 The Official Red Hat Linux Customization Guide 3 redhat Red Hat Linux 7 3 The Official Red Hat Linux Customization Guide Copyright 2002 by Red Hat Inc gt Red Hat Inc 1801 Varsity Drive Raleigh NC 27606 2072 USA Phone 1 919 754 3700 Phone 888 733 4281 Fax 1 919 754 3701 PO Box 13588 Research Triangle Park NC 27709 USA rhl cg EN 7 3 HTML RHI 2002 04 05T14 34 0400 Copyright 2002 by Red Hat Inc This material may be distributed only subject to the terms and conditions set forth in the Open Publication License V1 0 or later the latest version is presently available at http www opencontent org openpub Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder Distribution of the work or derivative of the work in any standard paper book form for commercial purposes is prohibited unless prior permission is obtained from the copyright holder The admonition graphics note tip and so on were created by Marianne Pecci lt goddess ipass net gt They may be redistributed with written permission from Marianne Pecci and Red Hat Inc Red Hat Red Hat Network the Red Hat Shadow Man logo RPM Maximum RPM the RPM logo Linux Library PowerTools Linux Undercover RHmember RHmember More Rough Cuts Rawhide and all Red Hat based trademarks and logos are trademarks or registered trademarks of Red Hat Inc in t
90. Samba SMB Printev 184 21 4 Adding a Novell NetWare NCP Printer 185 21 5 Adding a JetDirect Printer 0cccecee 186 21 6 Selecting the Print Driver and Finishing 188 21 7 Printing a Test Page inasin teti aineinaan i aian ia aeaeaei iienaa 190 21 8 Modifying Existing Printers sss ssssssssssssssserssstsssstsessststssstrtesntssssnssteessstt 190 21 9 Saving the Configuration File 192 21 10 Managing Your Print Jobs 04 193 21 11 Configuring the CUPS Printing System 193 21 12 Additional Resources ceccseeceseeees 195 22 Automated Tasks cccseee 197 22 1 Cron 197 22 2 Anacron 199 22 3 At and Batch wes 200 22 4 Additional Resources 202 23 Ugrading the Kernel 205 23 1 The 2 4 Kernel 205 23 2 Preparing to Upgrade 205 23 3 Downloading the Upgraded Kernel c ccecccsecessesesseeseeeseessesestesneseeneans 206 23 4 Performing the Upgrade ccccescescsssssessessesseseesessesseseesseesneseesesesteseeneaneanens 207 23 5 Configuring the Boot Loader 208 24 Kernel Modules ccccscescessesteseeeeseees 211 24 1 Kernel Module Utilities Peed 24 2 Additional Resources cccceesesessesesseseeseseescseceeseesesceseecseeseseeseeeseeseeeseeees 212 IV Package Management ssssssssssssssssssseesssesesssessssssnessenssnssneseencensssssensensenssseaeeaeeneseeneeneeneene
91. System Information chapter has been expanded to include a Monitoring Filesystems section which covers the diskcheck utility Printer Configuration This chapter has been expanded to include information on the alternative printing sys tem called CUPS Automated Tasks The at and batch commands have been added to this chapter Upgrading the Kernel The Upgrading the Kernel chapter has been expanded to include information on Red Hat Linux kernels built for different x86 architecture chips such as the AMD Athlon and the Intel Pentium 4 Building a Custom Kernel The Building a Custom Kernel chapter included instructions for using the Red Hat con fig files to recompile the kernel with the existing configuration options Kerberos All the Kerberos information has been merged into one location in the Official Red Hat Linux Reference Guide 2 Document Conventions When you read this manual you will see that certain words are represented in different fonts typefaces sizes and weights This highlighting is systematic different words are rep resented in the same style to indicate their inclusion in a specific category The types of words that are represented this way include the following Introduction xi command Linux commands and other operating system commands when used are represented this way This style should indicate to you that you can type the word or phrase on the command line and press Enter to invoke a comma
92. T 4 0 Service Pack 3 or higher you can either edit your Windows registry to use plaintext passwords or configure Samba on your Linux system to use encrypted passwords If you choose to modify your registry you must do so for all your Windows NT or 2000 machines this is risky and may cause further conflicts To configure Samba on your Red Hat Linux system to use encrypted passwords follow these steps BR Create a separate password file for Samba To create one based on your existing etc passwd file at a shell prompt type the following command cat etc passwd mksmbpasswd sh gt etc samba smbpasswd If the system uses NIS type the following command ypcat passwd mksmbpasswd sh gt etc samba smbpasswd The mksmbpasswd sh script is installed in your usr bin directory with the samba package 2 Use the command chmod 600 etc samba smbpasswd to change permissions on the Samba password file so that only root has read and write permissions 3 The script does not copy user passwords to the new file To set each Samba user s pass word use the command smbpasswd username replace username with each user s username A Samba user account will not be active until a Samba password is set for it 4 Encrypted passwords must be enabled in the Samba configuration file In the file smb conf verify that the following lines are not commented out encrypt password yes smb passwd file etc samba smbpasswd 5 Make sure the s
93. The default boot entry is set to number 0 To make your new kernel the default either place its section first or change the default entry number to the appropriate number remember that it starts counting with 0 For GRUB you do not need to run any commands after mod ifying the configuration file From now on when the system boots you will see the following GRUB boot options Red Hat Linux 2 4 18 0 12 ju12001 Red Hat Linux 2 4 18 0 12 To boot the default kernel press Enter or wait for it to time out If you want to boot the old kernel select it and press Enter You can begin testing your new kernel by rebooting your computer and watching the mes sages to ensure that your hardware is detected properly Appendix A Building a Custom Kernel 251 A 3 2 LILO To configure LILO to boot the new kernel you need to update the etc lilo conf file and run the command sbin lilo v The default etc 1ilo conf file looks similar to the following boot dev hda map boot map install boot boot b prompt timeout 50 message boot message linear default linux image boot vmlinuz 2 4 18 0 12 label linux initrd initrd 2 4 18 0 12 img read only root dev hda5 To add your new kernel to LILO copy the existing image section to a new one and modify it to boot your new kernel image and initrd image if you have any SCSI devices and have created an initrd image Also rename the label of the old kernel to something such as linux
94. a DHCP Clients iseasi raie iis 116 12 4 Additional Resources ccescecesseseesessestesestesesseeseseeseesessesseseeseaseensseeseeneenes 116 13 Apache Configuration 119 13 1 Basic Settings 119 13 2 Default Settings 121 13 3 Virtual Hosts Settings 127 13 4 Server Settings 132 13 5 Performance Tuning 134 13 6 Saving Your Settings 135 13 7 Additional Resources 135 14 Apache Secure Server Configuration 137 141 Introduction insna p 137 14 2 An Overview of Security Related Packages 14 3 An Overview of Certificates and Security 139 14 4 Using Pre Existing Keys and Certificates ccccccesesceseeseeesesteseeseeness 140 14 5 Types of Certificates dhs dinen teiro iiare eai iE ear RE 141 14 6 Generating a Key ssssssssssssssssssssssrssrtsssssssesssstese 142 14 7 Generating a Certificate Request to Send toa CA 143 14 8 Creating a Self Signed Certificate sccccee 145 14 9 Testing Your Certificate 146 14 10 Accessing Your Secure Server 147 14 11 Additional Resources 148 15 BIND Configuration ccccseseeseeceees 149 15 1 Adding a Forward Master Zone c scsccssescesesseseeseetesteseeseeessesnesesseanesnesees 150 15 2 Adding a Reverse Master Zone c sccsessessesseseeseesestsseeseesesssstesesseanesnesees 152 15 3 Adding a Slave Zone 0 0 154 16 Ma
95. a printer on the remote Windows machine Notice the syntax of machinename sharename e User The name of the user you must log in as to access the printer This user must exist on the Windows system and the user must have permission to access the printer The user name is typically guest for Windows servers or nobody for Samba servers Host IP The hostname or IP address of the remote system that is sharing the SMB printer e Password The password if required for the user specified in the User field Chapter 21 Printer Configuration 185 Workgroup The name of the workgroup on the machine running Samba Click the Translate n gt r n button to translate the end of line characters to a form that is readable by a Microsoft Windows system Click Next to continue Configure a Windows Print Queue Configure the SMB share of your remote printer Share User machinename sharename guest Host IP Password Workgroup devel I Translate n gt rin lt q Back gt Next X amp Cancel Figure 21 8 Choosing the Print Server The next step is to select the type of printer that is connected to the remote SMB system Skip to Section 21 6 to continue rote If you require a username and password for an SMB LAN Manager or NCP NetWare print queue they are stored unencrypted in a local script Thus it is possible for another person to learn the username and password To avoid this the
96. aY 19 Jam iwlfXox Hj lorMKnORIkeBcZ iLyPHLOA0I33Ft OHBaLtqdtP4vll ORbibjli BMEc END PGP PUBLIC KEY BLOCK mykey asc END Figure B 2 Copying Your Public Key Note that if you are submitting your key to another Web based keyserver the above trans action will be essentially the same That is all you need to do Regardless of whether you use the shell prompt or the Web you will see a message that your key was successfully submitted either at the shell prompt or at the keyserver s website From now on users who want to communicate securely with you can import your public key and add it to their keyring Appendix B Getting Started with Gnu Privacy Guard 259 B 5 Importing a Public Key The other end of key exchange importing other people s public keys to your keyring is just as simple as exporting keys When you import someone s public key you can decrypt their mail and check their digital signature against their public key on your keyring One of the easiest ways to import a key is to download the key or save it from a website To learn how to import Red Hat s key refer to Section 25 3 1 After downloading a key use the command gpg import key asc to add it to your keyring Another way to save a key is to use a browser s Save As feature If you are using a browser such as Navigator and you locate a key at a keyserver you can save the page as a text file go to File gt Save As In the
97. ab specifies that your system is set to shutdown and reboot the sys tem in response to a Ctrl Alt Del key combination used at the console If you would like to completely disable this ability you will need to comment out the following line in etc inittab by putting a hash mark in front of it ca ctrlaltdel sbin shutdown t3 r now Alternatively you may just want to allow certain non root users the right to shutdown the system from the console using Ctrl Alt Del You can restrict this privilege to certain users by taking the following steps 1 Add a a option to the etc inittab line shown above so that it reads ca ctrlaltdel sbin shutdown a t3 r now The a flag tells shutdown to look for the etc shutdown allovw file which you will create in the next step 2 Create a file named shutdown allowin etc The shutdown allovw file should list the usernames of any users who are allowed to shutdown the system using Ctrl Alt Del The format of the etc shut down allow file is a list of usernames one per line like the following stephen jack sophie According to this example shutdown allow file stephen jack and sophie are allowed to shutdown the system from the console using Ctrl Alt Del When that key combination is used the shutdown a in etc inittab checks to see if any of the users in etc shutdown allow or root are logged in on a virtual console If one of them is the 160 Chapter 17 Co
98. able types The lt partitions gt which denotes that multiple partitions can be listed lists the RAID identifiers to add to the RAID array level lt level gt RAID level to use 0 1 or 5 device lt mddevice gt Name of the RAID device to use such as md0 or md1 RAID devices range from md0 to md7 and each may only be used once spares N Specifies that there should be N spare drives allocated for the RAID array Spare drives are used to rebuild the array in case of drive failure fstype Sets the filesystem type for the RAID array Valid values are ext2 ext3 swap and vfat Chapter 1 Kickstart Installations 33 noformat Do not format the RAID array The following example shows how to create a RAID level 1 partition for and a RAID level 5 for usr assuming there are three SCSI disks on the system It also creates three swap partitions one on each drive part raid 01 size 60 ondisk sda part raid 02 size 60 ondisk sdb part raid 03 size 60 ondisk sde part swap size 128 ondisk sda part swap size 128 ondisk sdb part swap size 128 ondisk sdc part raid 11 size 1 grow ondisk sda part raid 12 size 1 grow ondisk sdb part raid 13 size 1 grow ondisk sdg raid level 1 device md0 raid 01 raid 02 raid 03 raid usr level 5 device md1 raid 11 raid 12 raid 13 1 4 21 reboot reboot optional Reboot after the installation is complete no arguments Normall
99. ablingCtrlAltDel 159 SMB protocol 107 smb conf 107 Software RAID See RAID ssh See OpenSSH striping RAID fundamentals 63 system information filesystems 174 monitoring 175 gathering 171 hardware 175 memory usage 173 processes 171 T TCP wrappers 92 telinit 92 telnet 97 testing certificates 146 time configuration 163 time zone configuration 165 timetool 163 token ring connection See network configuration top 171 U upgrading from secure server 1 0 or 2 0 140 packages with Gnome RPM 241 URLs for your secure server 147 user configuration adding users 167 adding users to groups 169 changing full name 169 changing home directory 169 changing login shell 169 changing password 169 filtering list of users 167 locking user accounts 169 modify groups for a user 168 modifying users 168 password expiration 169 setting user account expiration 169 viewing list of users 167 User Manager See user configuration users See user configuration V VeriSign using existing certificate 140 Ww Windows file and print sharing 107 Windows 2000 connecting to shares using Samba 108 Windows NT 4 0 connecting to shares using Samba 108 X See network configuration xDSL connection xinetd 92
100. ackage is processed by RPM s freshen option it will be upgraded to the newer version However RPM s freshen option will not install a package if no previously installed package of the same name exists This differs from RPM s upgrade option as an upgrade will install packages whether or not an older version of the package was already installed RPM s freshen option works for single packages or a group of packages If you have just downloaded a large number of different packages and you only want to upgrade those packages that are already installed on your system freshening will do the job If you use freshening you will not have to deleting any unwanted packages from the group that you downloaded before using RPM In this case you can simply issue the following command rpm Fvh rpm RPM will automatically upgrade only those packages that are already installed 25 2 6 Querying Use the rpm q command to query the database of installed packages The rpm q foo com mand will print the package name version and release number of the installed package foo rpm q foo foo 2 0 1 222 Chapter 25 Package Management with RPM rote Notice that we used the package name foo To query a package you will need to replace foo with the actual package name Instead of specifying the package name you can use the following options with q to specify the package s you want to query These are called Package Specification Options
101. ad the configuration files You can also choose File gt Exit and click Yes to Do you want to apply your changes before exiting 15 1 Adding a Forward Master Zone To add a forward master zone also known as a primary master click the Add button select Forward Master Zone and enter the domain name for the master zone in the Domain name text area A new window as shown in Figure 15 2 will appear with the following options Name Domain name that was just entered in the previous window e File Name File name of the DNS database file relative to var named e Contact Email address of the main contact for the master zone Primary Name Server SOA State of authority SOA record This specifies the name server that is the best resource of information for this domain The default value is which means that the SOA is the same as the domain name entered in the Name field above Serial Number The serial number of the DNS database file This number must be in cremented each time the file is changed so that the slave name servers for the zone will retrieve the latest data The BIND Configuration Tool increments this number each time Chapter 15 BIND Configuration 151 the configuration changes It can also be incremented manually by clicking the Set button next to the Serial Number value Time Settings The Refresh Retry Expire and Minimum TTL Time to Live values that are stored in the DNS database f
102. ain Menu Button on the Panel gt Programs gt System gt Network Configuration e On the KDE desktop go to the Main Menu Button on the Panel gt System gt Network Configuration e Type the command redhat config network at a shell prompt for example in an XTerm or a GNOME terminal If you prefer modifying the configuration files directly refer to the Official Red Hat Linux Reference Guide for information on their location and contents rip Go to the Red Hat Hardware Compatibility List http hardware redhat com hcl to determine if Red Hat Linux supports your hardware device 6 1 Overview To configure a network connection with the Network Administration Tool perform the following steps 1 Add the physical hardware device to the hardware list 2 Add a network device associated with the physical hardware device 3 Configure any hosts that can not be looked up through DNS 4 Configure the hostname and DNS settings 74 Chapter 6 Network Configuration This chapter will discuss each of these steps for each type of network connection 6 2 Establishing an Ethernet Connection To establish an Ethernet connection you need a network interface card NIC a network cable usually a CAT5 cable and a network to connect to There are different speeds to networks make sure your NIC is compatible with the network to which you want to connect To add an Ethernet connection follow these steps 1 Click the D
103. al of all member disks the array which wastes drive space For example if you have RAID level 1 set up so that your root partition exists on two 40G drives you have 80G total but are only able to access 40G of that 80G The other 40G acts like a mirror of the first 40G 3 This information can then be used to reconstruct data when one disk in the array fails The recon Parity information is calculated based on the contents of the rest of the member disks in the array structed data can then be used to satisfy I O requests to the failed disk before it is replaced and to repopulate the failed disk after it has been replaced 4 than level 4 For this reason level 4 is not supported RAID level 4 takes up the same amount of space as RAID level 5 but level 5 has more advantages 66 Chapter 4 Redundant Array of Independent Disks RAID 3 redhat Chapter 5 Software RAID Configuration Read Chapter 4 first to learn about RAID the differences between Hardware and Software RAID and the differences between RAID 0 1 and 5 Software RAID can be configured during the graphical installation of Red Hat Linux or during a kickstart installation You can use fdisk or Disk Druid to create your RAID con figuration but these instructions will focus mainly on using Disk Druid to complete this task Before you can create a RAID device you must first create RAID partitions using the fol lowing step by step instructions Qr
104. appropriate for most situations Chapter 13 Apache Configuration 133 Main Virtual Hosts Server Performance Tuning Lock File varf lock httpd lock Browse PID File ivar run hitpd pid E Browse Core Dump Directory etc httpd A Browse User apache Group apache oK X Cancel Help Figure 13 13 Server Configuration The Lock File value corresponds to the LockFi1le directive This directive sets the path to the lockfile used when Apache is compiled with either USELFCNTL_SERIALIZED_ACCEPT or USE_FLOCK_SERIALIZED_ACCEPT It must be stored on the local disk It should be left to the default value unless the logs directory is located on an NFS share If this is the case the default value should be changed to a location on the local disk and to a directory that is readable only by root The PID File value corresponds to the PidFile directive This directive sets the file in which the server records its process ID pid This file should only be readable by root In most cases it should be left to the default value The Core Dump Directory value corresponds to the CoreDumpDirectory directive Apache tries to switch to this directory before dumping core The default value is the ServerRoot However if the user that the server runs as can not write to this directory the core dump can not be written Change this value to a directory writable by the user the server runs as if you want to write the core dumps to dis
105. aracters beyond the basic ASCII set but they are not printing correctly such as Japanese characters This option will prerender non standard PostScript fonts so that they are printed correctly If your printer does not support the fonts you are trying to print try selecting this option For example you should select this option if you are printing Japanese fonts to a non Japanese printer Extra time is required to perform this action Do not choose it unless you are having prob lems printing the correct fonts Convert Text to Postscript is selected by default If your printer can print plain text try unselecting this when printing plain text documents to decrease the time it takes to print Page Size allows you to select the paper size for your printer such as US Letter US Legal A3 and A4 Effective Filter Locale defaults to C If you are printing Japanese characters select ja_JP Otherwise accept the default of C If you modify the driver options click OK to return to the main window Click Apply to save the change and restart the printer daemon 21 9 Saving the Configuration File When you save your printer configuration using printconf it creates its own configuration file that is used to create the etc printcap file that the printer daemon 1pd reads You can use the command line options to save or restore this file If you save your etc printcap file and overwrite your existing etc printcap file with the saved file y
106. are quite a few fields but you can leave some blank For some fields there will be a default value If you enter the field will be left blank Country Name 2 letter code AU US State or Province Name full name Some State North Carolina Locality Name eg city Durham Organization Name eg company Internet Widgits Test Company Organizational Unit Name eg section Testing Common Name your name or server s hostname test example com Email Address admin example com Please enter the following extra attributes to be sent with your certificate request A challenge password An optional company name The default answers appear in brackets immediately after each request for input For example the first information required is the name of the country where the certificate will be used shown like the following Country Name 2 letter code AU The default input in brackets is AU To accept the default just press Enter or fill in your country s two letter code You will have to type in the rest of the inputs State or Province Name Locality Name Organization Name Organizational Unit Name Common Name and Email address All of these should be self explanatory but you need to follow these guidelines Do not abbreviate the locality or state Write them out for example St Louis should be written out as Saint Louis e If you are sending this CSR to a CA be very careful to
107. art the service Do not create a new lease file if this occurs If you do all the old leases will be lost and cause many problems The correct solution is to rename the dhcpd leases backup file to dhcpd leases and then start the daemon 12 2 3 Starting and Stopping the Server Occ Before you start the DHCP server for the first time it will fail unless there is an existing dhcpd leases file Use the command touch var lib dhcp dhcpd leases to create the file if it does not exist Chapter 12 Dynamic Host Configuration Protocol DHCP 115 To start the DHCP service use the command sbin service dhcpd start To stop the DHCP server use the command sbin service dhcpd stop If you want the daemon to start automatically at boot time see Chapter 8 for information on how to manage services If you have more than more network interface attached to the system but you only want the DHCP server to start on one of the interface you can configure the DHCP server to start only on that device In etc sysconfig dhcpd add the name of the interface to the list of DHCPDARGS Command line options here DHCPDARGS eth0 This is useful if you have a firewall machine with two network cards One network card can be configured as a DHCP client to retrieve an IP address to the Internet The other network card can be used as a DHCP server for the internal network behind the firewall Specifying only the network card connected to the internal network make
108. asks 22 3 4 Additional Command Line Options Additional command line options for at and batch include Table 22 1 at and batch Command Line Options Option Description o f Read the commands or shell script from a file instead of specifying them at the prompt Send email to the user when the job has been completed Display the time that the job will be executed 22 3 5 Controlling Access to At and Batch The etc at allow and etc at deny files can be used to restrict access to the at and batch commands The format of both access control files is one username on each line Whitespace is not permitted in either file The at daemon atd does not have to be restarted if the access control files are modified The access control files are read each time a user tries to execute the at or batch commands The root user can always execute at and batch commands regardless of the access control files If the file at allow exists only users listed in it are allowed to use at or batch and the at deny file is ignored If at allow does not exist all users listed in at deny are not allowed to use at or batch 22 3 6 Starting and Stopping the Service To start the at service use the command sbin service atd start To stop the service use the command sbin service atd stop It is recommended that you start the service at boot time Refer to Chapter 8 for details on starting the cron service automatically at boot time 22 4 A
109. at serve requests for the realm If you have multiple KDCs in your realm separate their names with commas krb5adminserver The KDC in your realm that is also running kadmind This server handles password changing and other administrative requests This server must be run on the master KDC if you have more than one KDC enablehesiod Enable Hesiod support for looking up user home directories UIDs and shells More information on setting up and using Hesiod on your network is in usr share doc glibc 2 x x README hesiod which is included in the glibc package Hesiod is an extension of DNS that uses DNS records to store information about users groups and various other items hesiodlhs The Hesiod LHS left hand side option set in etc hesiod conf This option is used by the Hesiod library to determine the name to search DNS for when looking up information similar to LDAP s use of a base DN hesiodrhs The Hesiod RHS right hand side option set in etc hesiod conf This option is used by the Hesiod library to determine the name to search DNS for when look ing up information similar to LDAP s use of a base DN rip To look up user information for jim the Hesiod library looks up jim passwd lt LHS gt lt RHS gt which should resolve to a TXT record that looks like what his passwd entry would look like jim 501 501 Jungle Jim home jim bin bash For groups the situation is identical except jim group
110. atic Improvements in the Linux 2 0 x kernels allowed for many hardware drivers to be modularized into components that are loaded on demand How ever major problems existed when users had multiple kernels that had been compiled for different configuration options on their system for example SMP versus UP kernels Fur ther Linux 2 4 x kernel modularization advancements allow for multiple kernels to co exist more easily but they can not share modules For information on handling kernel modules see Chapter 24 Unless you are recompiling a customized kernel for your system you will not see many changes in how kernel modules are handled A 1 Building a Modularized Kernel The instructions in this section apply to building a modularized kernel If you are interested in building a monolithic kernel instead see Section A 4 for an explanation of the different aspects of building and installing a monolithic kernel The following steps will guide you through building a custom kernel for the x86 architecture rote This example uses 2 4 18 0 12 as the kernel version Your kernel version might differ To determine your kernel version type the command uname r Replace 2 4 18 0 12 with your kernel version BR The most important step is to make sure that you have a working emergency boot disk in case you make a mistake If you did not make a boot disk during the installation use the mkboot disk command to make one now The standard command is s
111. ation Tool requires the X Window System and root access To start the BIND Configuration Tool use one of the following methods On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt DNS Configuration e On the KDE desktop go to the Main Menu Button on the Panel gt System gt DNS Configuration e Type the command bindcon at a shell prompt for example in an XTerm or GNOME terminal 150 Chapter 15 BIND Configuration File Help H e example com E localhost E 0 0 127 in addr arpa 3 3 2 1 in addr arpa E forward example com H 3 2 1 in addr arpa Figure 15 1 bindconf The BIND Configuration Tool configures the default zone directory to be var named All zone files specified are relative to this directory The BIND Configuration Tool also includes basic syntax checking when values are entered For example if a valid entry is an IP address you are only allowed to type numbers and the dot character into the text area The BIND Configuration Tool allows you to add a forward master zone a reverse master zone and a slave zone After adding the zones you can edit or delete them from the main window as shown in Figure 15 1 After adding editing or deleting a zone you must choose File gt Apply to write the etc named conf configuration file and all the individual zone files in the var named di rectory Applying your changes will also have the named service relo
112. ature of an RPM file after importing the builder s GnuPG key use the following command replace coolapp with the filename of your RPM package rpm checksig coolapp 1 1 1 rpm If all goes well you will see the message md5 gpg OK That means that the package is not corrupt 25 3 3 More about GnuPG For more information about GnuPG see Appendix B Chapter 25 Package Management with RPM 225 25 4 Impressing Your Friends with RPM RPM is a useful tool for both managing your system and diagnosing and fixing problems The best way to make sense of all of its options is to look at some examples e Perhaps you have deleted some files by accident but you are not sure what you deleted If you want to verify your entire system and see what might be missing you could try the following command rpm Va If some files are missing or appear to have been corrupted you should probably either re install the package or uninstall then re install the package e At some point you might see a file that you do not recognize To find out which package owns it you would enter rpm qf usr X11R6 bin ghostview The output would look like the following gv 3 5 8 10 e We can combine the above two examples in the following scenario Say you are having problems with usr bin paste You would like to verify the package that owns that pro gram but you do not know which package owns paste Simply enter the following com mand rpm Vf usr b
113. aving the File 3 Rescue Mode ceseeccscecceseescees ee 3 1 What is Rescue Mod e ccccccsessessessesesseesestessesesessesnesesseeseseesseseasssnesesseaseseenees 59 3 2 Booting Rescue Mode sccsessessesessesseseeesteseesestessessesesseesesseseeseaneseseseaseanenees 60 3 3 Booting Single User Mode 00 61 4 Redundant Array of Independent Disks RAID v 63 4 1 What is RAID erie ne oeiee daas E aeea ieta EEE EEEE A E EAER 63 4 2 Who Should Use RAID insin ne i aE EEE EERE iasi 63 4 3 Hardware RAID versus Software RAID 63 4 4 RAID Levels and Linear Support we 64 5 Software RAID Configuration 167 II Network Related References scssesssssssseressessessensssssncssescsssssssseneessscsneneeacsncsseseesssnesseseeneens 71 6 Network Configuratii pie e a 73 6 1 OVOLVICW iisi 73 6 2 Establishing an Ethernet Connection 6 3 Establishing an ISDN Connection 7d 6 4 Establishing a Modem Connection 76 6 5 Establishing an xDSL Connection 78 6 6 Establishing a Token Ring Connection old 6 7 Establishing a CIPE Connection we 81 6 8 Establishing a Wireless Connection sabl 6 9 Managing Hosts 0 83 6 10 Managing DNS Settings 84 7 Basic Firewall Configuration 87 7 1 BaSiC iiine 87 7 2 Local Hosts 88 PD wen A ns hue Simmons lected gil a TAs Configuring SOLVICES enice i eeoa i Ei eeke AEREE Sa E 89 7 5 Activating the Fir wall Sanrion
114. bout CUPS redhat Chapter 22 Automated Tasks In Linux tasks can be configured to run automatically within a specified period of time on a specified date or when the system load average is below a specified number Red Hat Linux comes preconfigured to run important system tasks to keep the system updated For example the slocate database used by the locate command is updated daily A system administrator can use automated tasks to perform periodic backups monitor the system run custom scripts and more Red Hat Linux comes with four automated tasks utilities cron anacron at and batch 22 1 Cron Cron is a daemon that can be used to schedule the execution of recurring tasks according to a combination of the time day of the month month day of the week and week Cron assumes that the system is on continuously If the system is not on when a task is scheduled it is not executed To configure tasks based on time periods instead of exact times refer to Section 22 2 To schedule one time tasks refer to Section 22 3 To use the cron service you must have the vixie cron RPM package installed and the crond service must be running To determine if the package is installed use the rpm q vixie cron command To determine if the service is running use the command sbin service crond status 22 1 1 Configuring Cron Tasks The main configuration file for cron etc crontab contains the following lines SHELL bin bash PATH
115. ccessfully 2 Re initialize the runlevel Reinitialize the runlevel by going to a shell prompt such as an XTerm or GNOME terminal and typing the command telinit 3 where 3 is the runlevel number This option is recommended if you change the Start at Boot value of more than one service and want to activate the changes immediately 3 Do nothing else You do not have to stop the anacron service You can wait until the system is rebooted for the service to stop The next time the system is booted the runlevel will be initialized without the anacron service running 8 4 ntsysv The ntsysv utility provides a simple interface for activating or deactivating services You can use ntsysv to turn an xinetd managed service on or off You can also use ntsysv to start or stop a service in the etc rc d hierarchy in that case the nt sysv command without op tions is used to configure current runlevel If you want to configure a different runlevel use something like ntsysv levels 016 In this example you would be setting the services for runlevels 0 1 and 6 The ntsysv interface works like the text mode installation program Use the up and down arrows to navigate up and down the list The space bar selects unselects services and is also used to press the Ok and Cancel buttons To move between the list of services and the Ok and Cancel buttons use the Tab key An signifies that a service is set to on The F1 key will pop up a short
116. ccurred may leave some files around To clean up after this error reinstall the package after you have made more disk space available 242 Chapter 26 Gnome RPM redhat Chapter 27 Red Hat Network Red Hat Network is an Internet solution for managing a Red Hat Linux system or a network of Red Hat Linux systems All Security Alerts Bug Fix Alerts and Enhancement Alerts col lective known as Errata Alerts can be downloaded directly from Red Hat using the Red Hat Update Agent standalone application or through the RHN Web interface available at http rhn redhat com Red Hat Network saves Red Hat Linux users time because they receive email when updated packages are released Users do not have to search the Web for updated packages or security alerts By default Red Hat Network installs the packages as well Users do not have to learn how to use RPM or worry about resolving software package dependencies RHN does it all Each Red Hat Network account comes with Errata Alerts learn when Security Alerts Bug Fix Alerts and Enhancement Alerts are issued for all the systems in your network through the Basic interface e Automatic email notifications receive an email notification when an Errata Alert is is sued for your system Scheduled Errata Updates schedule delivery of Errata Updates with optional automatic installation e Package installation Schedule package installation on one or more systems with the click of
117. choosing a CA 141 CIPE connection See network connection configuration console access 159 Gnome RPM 234 NES 103 console making files accessible from 161 console access configuring 159 defining 160 disabling 160 disabling all 160 enabling 161 conventions document x Cron 197 additional resources 202 262 configuration file 197 example crontabs 198 user defined tasks 198 crontab 197 CtrlAltDel shutdown disabling 159 D date configuration 163 decryption with GnuPG 253 devel package 138 df 174 DHCP 111 additional resources 117 client configuration 116 command line options 115 connecting to 116 dhepd conf 111 dhcpd leases 114 dhcrelay 115 global parameters 112 group 112 options 111 reasons for using 111 Relay Agent 115 server configuration 111 shared network 112 starting the server 114 stopping the server 114 subnet 112 dhepd conf 111 dhcpd leases 114 dhcrelay 115 diskcheck 175 DSA keys 99 DSOs loading 138 du 174 dual boot configuring GRUB 250 configuring LILO 251 Dynamic Host Configuration Protocol See DHCP E encryption with GnuPG 253 Ethernet connection See network configuration exporting NFS filesystems 105 F eedback xiv ilesystem NFS See NFS ilesystems 174 irewall See GNOME Lokkit irewall configuration during installation 87 floppy group use of 162 ree 173 tp 97 G GNOME Lokkit activati
118. cific runlevel For example to turn nscd off in runlevels 3 4 and 5 use the command chkconfig level 345 nscd off See the chkconfig man page for more information on how to use it warning Services managed by xinetd are immediately affected by chkconfig For example if xinetd is running finger is disabled and the command chkconfig finger on s executed finger is im mediately enabled without having to restart xinetd manually Changes for other services do not take effect immediately after using chkconfig You must stop or start the individual service with the command service daemon stop In the previous example replace daemon with the name of the service you want to stop for example httpd Replace stop with start or restart to start or restart the service 8 6 Additional Resources For more information on xinetd refer to the following resources 96 8 6 1 e man e man e man e man e man Chapter 8 Controlling Access to Services Installed Documentation nt sysv The ntsysv man page chkconfig The chkconfig man page xinetd The xinetd man page xinetd conf The man page for the xinetd conf configuration file 5 hosts_access The man page for the format of host access control files in sec tion 5 of the man pages 8 6 2 Useful Websites http www xinetd org The xinetd webpage It contains the a more detailed list of features and sample configuration files reana
119. cons that represent the packages You can change that view to a list view by selecting Operations gt Preferences from the pull down menu clicking on the Package Listing tab and selecting View as list Refer to Section 26 4 for more information about customizing Gnome RPM settings 26 2 1 Selecting Packages To select a single package click on it with the left mouse button When a package is selected its title will be highlighted as shown in Figure 26 2 To unselect a package either click on an empty space in the display panel with the left mouse button or click on the Unselect button on the toolbar When you unselect a package the highlighting will disappear 232 Chapter 26 Gnome RPM Packages Operations Help o aje QUe B Install Unselect Uninstall Query Verify Find Web find G Packages E Amusements amp Be p amp p S G 8 Applications rchiving vim vim minimal 6 CPAN comman B 0 0 21 2 E Communications Cryptography Databases jed jed 0 ied xied 0 Engineering common 99 12 1 99 12 1 GFile 99 121 Galnternet e e888 Productivity A EAT ioe 2 nvi mi7n vim vim X11 6 xemacs 21 semi Packages selected 7 Figure 26 2 Selecting Packages in Gnome RPM You can select and unselect multiple packages in more than one folder in the tree panel To select more than one package hold down the Ctrl key and left click on packages each selected package will be highlighted To select a g
120. cs books 228 Chapter 25 Package Management with RPM 3 redhat Chapter 26 Gnome RPM If you do not want to use the command line version of RPM you can use Gnome RPM a graphical interface for Red Hat Package Manager RPM To learn more about RPM tech nology turn to Chapter 25 Gnome RPM which is also referred to as gnorpm allows users to easily work with RPM technology and features a friendly interface It is GNOME compliant meaning that it seamlessly integrates into GNOME a graphical X Window System desktop environment provided with Red Hat Linux Using Gnome RPM you can easily accomplish the following tasks Install RPM packages Uninstall RPM packages Upgrade RPM packages e Find new RPM packages e Query RPM packages e Verify RPM packages The Gnome RPM interface provides a menu a toolbar a tree and a window which displays currently installed packages To perform a Gnome RPM task you usually find and select packages then choose the type of operation to perform using either a button on the toolbar from the menu or by right clicking with the mouse Installing a package places all of the components of that package on your system in the correct locations Uninstalling a package removes all components of the package except for configuration files you have modified e Upgrading a package installs the new version and uninstalls all other versions that were previously installed You can also use the Web
121. ct ISDN connection from the Device Type list and click Next 4 Select the ISDN adapter from the pulldown menu Then configure the resources and D channel protocol for the adapter Click Next to continue 76 Chapter 6 Network Configuration Select ISDN Adapter ISDN Adapters ACER P10 Resource D Channel Protocol IRQ Euro ISON EDSS1 Mew lo oxao0 101 lt Back D Next X Cancel Figure 6 3 ISDN Settings 5 If your ISP is in the pre configured list select it Otherwise enter the required infor mation about your ISP account If you do not know the values contact your ISP Click Next 6 On the Create Dialup Connection page click Finish After configuring the ISDN device it appears in the device list as an ippp device as shown in Figure 6 4 Devices Hardware Hosts DNS You may configure network devices associated with physical hardware here Multiple logical devices can be associated with a single piece of hardware Status Device Nickname Type Add Edit 4 oo Copy Delete Activate Deactivate Monitor i GE PERE Pep _ v ay Figure 6 4 ISDN Device Be sure to click Apply to save the changes After adding the modem device you can edit its configuration by selecting the device from the device list and clicking Edit For example when the device is added it is configured not to start at boot time by defaul
122. d 130 Chapter 13 Apache Configuration Basic Setup Site Configuration Virtual Host Name ipbased SSL Logging Document Root Directory varAwww html ipbased 4 Browse Enylronment Variables Webmaster email address ipbased me com Directories i Host Information IP based Virtual Host IP Address 192 166 100 100 Server Host Name Jipbased me com 0K X Cancel Help Figure 13 10 IP Based Virtual Hosts 13 3 1 1 3 Name based Virtual Host If you choose Name based Virtual Host Figure 13 11 appears to configure the Namevir tualHost directive based on the host name of the server Specify the IP address in the IP address field To specify more than one IP address separate each IP address with spaces To specify a port use the syntax IP Address Port Use to configure all ports for the IP address Specify the host name for the virtual host in the Server Host Name field In the Aliases section click Add to add a host name alias Adding an alias here adds a Server Alias directive within the NameVirtualHost directive Chapter 13 Apache Configuration 131 Basic Setup Site Configuration SSL Logging Document Root Directory varAwww html namebased A Browse Enylronment Variables Webmaster email address namebased me com Directories ae Host Information Name based Virtual Host IP Address 192 168 100 200 Host Name namebased me com Aliases I gt Qa 2 Im 2 Delete
123. d Anaconda will probe the PCI bus for the card Since AGP is part of the PCI bus AGP cards will be detected if supported The probe order is determined by the PCI scan order of the motherboard videoram lt vram gt Specify the amount of video RAM the video card has Chapter 1 Kickstart Installations 35 monitor lt mon gt Use monitor lt mon gt this monitor name should be from the list of monitors in Xconfigurator This is ignored if hsync or vsync is provided If no monitor information is provided the installation program tries to probe for it automatically hsyne lt sync gt Specifies the horizontal sync frequency of the monitor vsyne lt sync gt Specifies the vertical sync frequency of the monitor defaultdesktop GNOME or defaultdesktop KDE Sets the default desktop to either GNOME or KDE and assumes that GNOME and or KDE has been installed through packages startxonboot Use a graphical login on the installed system resolution lt res gt Specify the default resolution for the X Window System on the installed system Valid values are 640x480 800x600 1024x768 1152x864 1280x1024 1400x1050 1600x1200 Be sure to specify a resolution that is compatible with the video card and monitor depth lt cdepth gt Specify the default color depth for the X Window System on the installed system Valid values are 8 16 24 and 32 Be sure to specify a color depth that is compatible with the v
124. d For example if you have an IDE CD ROM burner you can tell the kernel to use the SCSI emulation driver that must be loaded before using cdrecord by typing hdd ide scsi as a kernel parameter where hdd is the CD ROM device If you choose LILO as the boot loader choose whether you want to use linear mode and whether you want to force the use of lba32 mode If you choose GRUB as the boot loader you can password protect it by configuring a GRUB password Enter a password in the Use GRUB Password text entry area If you want to save the password as an encrypted password in the file select Encrypt GRUB password When the file is saved the plaintext password that you typed will be encrypted and written to the kickstart file Do not type an already encrypted password and select to encrypt it 2 3 Installation Method File Help Installation Method required Basic Configuration Boot Loader Options Installation Method Install C Upgrade Partition Information Network Configuration Authentication Choose the Installation Method Firewall Configuration X Configuration CD ROM C NFS C FTP C HTP C Hard Drive Package Selection Pre Installation Script Post Installation Script Save File X Cancel Help Figure 2 3 Installation Method The Installation Method screen allows you to choose whether you want to perform a full installation or an upgrade If you choose upgrade the Partition Informatio
125. d Name or a DN There are quite a few fields but you can leave some blank For some fields there will be a default value If you enter the field will be left blank Country Name 2 letter code AU US State or Province Name full name Some State North Carolina Locality Name eg city Durham Organization Name eg company Internet Widgits My Company Inc Organizational Unit Name eg section Documentation Common Name your name or server s hostname myhost example com Email Address myemail example com 146 Chapter 14 Apache Secure Server Configuration After you provide the correct information a self signed certificate will be created and placed in etc httpd conf ssl crt server crt You will need to restart your secure server after generating the certificate with following the command sbin service httpd restart 14 9 Testing Your Certificate When the secure server is installed by the Red Hat Linux installation program a random key and a generic certificate are installed for testing purposes You can connect to your secure server using this certificate For any purposes other than testing however you need to get a certificate from a CA or generate a self signed certificate See Section 14 5 if you need more information on the different types of certificates available If you have purchased a certificate from a CA or generated a self signed certificate you should have a file named etc httpd co
126. d directory ote The directory mnt must exist on the local filesystem There should be no subdirectories to mnt on the local filesystem Autofs is a service To start the service at a shell prompt type the following commands service autofs restart To view the active mount points type the following command at a shell prompt service autofs status If you modify the etc auto master configuration file while autofs is running you must tell the automount daemon s to reload by typing the following command at a shell prompt service autofs reload To learn how to configure autofs to start at boot time refer to Chapter 8 for information on managing services Chapter 10 Network File System NFS 105 10 3 Exporting NFS Filesystems The etc exports file controls what filesystems the NFS server exports Its format is as follows directory hostname options The options are not required For example mnt export speedy redhat com would allow users from speedy redhat com to mount mnt export with the default read only permissions but mnt export speedy redhat com rw would allow users from speedy redhat com to mount mnt export with read write privi leges Efon Be careful with spaces in the etc exports file If there are no spaces between the hostname and the options in parentheses the options apply only to the hostname If there is a space between the hostname and the options the options apply to the re
127. d domain name or IP address of the HTTP server For the HTTP directory en ter the name of the HTTP directory that contains the RedHat directory For example if your HTTP server contains the directory mirrors redhat i386 RedHat enter mir rors redhat i386 for the HTTP directory Hard Drive Choose this option if you wish to install Red Hat Linux from a hard drive Two text entry boxes for hard drive partition and hard drive directory will appear Hard drive installations require the use of ISO or CD ROM images Be sure to verify that the ISO images are intact before you start the installation To verify them use an md5sum program Enter the hard drive partition that contains the ISO images for exam ple dev hda1 in the Hard Drive Partition text box and enter the directory that contains the ISO images in the Hard Drive Directory text box 2 4 Partition Information File Help Basic Configuration Partition Information required Boot Loader Options Clear Master Boot Record C Yes No Installation Method Remove Partitions None C All C Linux Network Configuration Authentication Initialize the Disk Label C Yes No Firewall Configuration Package Selection ext3 50 Pre Installation Script swap 128 Post Installation Script i ext3 2048 50 Add Edit Delete Save File X Cancel Help Figure 2 4 Partition Information To clear the Master Boot Record select Yes beside the option on th
128. d of its expiration and supplied with a new public key Your next task is to provide a user ID with your name your email address and an optional comment When you are finished you will be presented with a summary of the information you entered Once you accept your choices you will have to enter a passphrase rip Like your account passwords a good passphrase is essential for optimal security in GnuPG For example mix your passphrase with uppercase and lowercase letters use numbers or punctuation marks Once you enter and verify your passphrase your keys will be generated You will see a message similar to the following We need to generate a lot of random bytes It is a good idea to perform some other action type on the keyboard move the mouse utilize the Appendix B Getting Started with Gnu Privacy Guard 255 disks during the prime generation this gives the random number generator a better chance to gain enough entropy pEr it ktt kett ttt E a EAEE E Eo tt a FHE HE Attest ttt Gaa aia aa a aia a aia a aia ada aia ada a mia al aa aia si aa sla aia ala sia da aia ada aa ala da a mla mla aia ada aa aia ada aa aia da PO When the activity on the screen ceases your new keys will be made and placed in the direc tory gnupg in your home directory To list your keys use the command gpg list keys You will see something similar to the following home newuser gnupg pubring gpg pub 1024D B7085C8A 2000 04 18 Your
129. dditional Resources To learn more about configuring automated tasks refer to the following resources 22 4 1 Installed Documentation cron man page overview of cron e crontab man pages in sections 1 and 5 The man page in section 1 contains an overview of the crontab file The man page in section 5 contains the format for the file and some example entries e usr share doc at lt version gt timespec contains more detailed information about the times that can be specified for cron jobs e anacron man page description of anacron and its command line options Chapter 22 Automated Tasks 203 e anacrontab man page brief overview of the anacron configuration file e usr share doc anacron lt version gt README describes Anacron and why it is useful e at man page description of at and batch and their command line options 204 Chapter 22 Automated Tasks redhat Chapter 23 Ugrading the Kernel The Red Hat Linux kernel is custom built by the Red Hat kernel team to ensure its integrity and compatibility with supported hardware Before Red Hat releases a kernel it must pass a rigorous set of quality assurance tests Official Red Hat Linux kernels are packaged in RPM format so that they are easy to upgrade and verify For example the kernel RPM package creates the initrd image it is not neces sary to use the mkinitrd command after installing a different kernel if you install the kernel from the Red Hat RPM
130. ded in the kickstart file during the installation but allow for inspection and modification of the values given You will be presented with each screen of the installation program with the values from the kickstart file Either accept the values by clicking Next or change the values and click Next to continue See also Section 1 4 1 1 4 12 keyboard keyboard required Sets system keyboard type Here is the list of available keyboards on i386 Itanium and Alpha machines azerty be latinl be2 latinl fr latinO fr latinl fr pc fr wangbe ANSI dvorak dvorak 1l dvorak r dvorak pc dvorak latinl tr_f latin5 trf bg br abnt2 cf cz lat2 prog cz lat2 defkeymap defkeymap_V1 0 dk latinl dk emacs emacs2 es fi latinl fi gr pc gr hebrew hul01 is latinl it ibm it it2 jp106 la latinl lt 1t 14 nl no latinl no PELLO pl pt latinl pt old ro ru cpl251 ru ms ru yawerty ru rul ru2 ru_win se latinl sk prog qwerty sk prog sk qwerty tr_q latin5 tralt trf trd ua uk us croat cz us qwertz de latinl nodeadkeys de latinl de fr_CH latinl fr_CH hu sg latinl 1k450 sg latinl sg sk prog qwertz sk qwertz slovene Here is the list for SPARC machines sun pl altgraph sun pl sundvorak sunkeymap sunt4 es sunt4 no latinl sunt5 cz us sunt5 de latinl sunt5 es sunt5 fi latinl sunt5 fr latinl sunt5 ru sunt5 uk sunt5 us cz 1 4 13 lang lang required Sets the language to use during ins
131. default home page as shown in Figure 14 1 Chapter 14 Apache Secure Server Configuration 147 File Edit View Go Window Help A Back Forward Reload Home Print stop a Bookmarks amp Location https localhost z EI What s Related Test Page This page is used to test the proper operation of the Apache Web server after it has been installed If you can read this page it means that the Apache Web server installed at this site is working properly If you are the administrator of this website You may now add content to this directory and replace this page Note that until you do so people visiting your website will see this page and not your content If you have upgraded from Red Hat Linux 6 2 and earlier then you are seeing this page because the default DocumentRoot set in etc httpd conf httpd conf has changed Any subdirectories which existed under home httpd should now be moved to var www Altematively the contents of var winr can be moved to home httpd and the configuration file can be updated accordingly If you are a member of the general public The fact that you are seeing this page indicates that the website you just visited is either experiencing problems or is undergoing routine maintenance If you would like to let the administrators of this website know that you ve seen this page instead of the page you expected you should send them e mail In general mail sent to the name
132. deo card is selected by default Accept this default if you want the installation program to probe for the video card during installation Probing works for most modern video cards If you select this option and the installation program can not successfully probe the video card the installation program will stop at the video card configuration screen To continue the installation process select your video card from the list and click Next Alternatively you can select the video card from the list on the Video Card tab as shown in Figure 2 10 Also select the amount of video RAM the selected video card has from the Video Card RAM pulldown menu These values will be used by the installation program to configure the X Window System 52 Chapter 2 Kickstart Configurator File Help X Configuration Basic Configuration Boot Loader Options IZ Configure the X Window System Installation Method Partition Information General Video Card Monitor Network Configuration Authentication Probe for video card Firewall Configuration Select a Video Card al Proper roe ooo Machspeed Raptor i740 AGP 4600 Magic Pro MP 740DVD Matrox Comet Matrox Marvel Il Matrox Millennium Matrox Millennium G200 Package Selection Pre Installation Script Post Installation Script M ennium G400 Matrox Millennium G450 Matrox Millennium II Matrox Mystique Matrox Mystique G200 Matrox Productiva G100 Mediavision Proaxcel
133. drives reach 90 capacity e cutoff dev partition Override the defaultCutoff for the partition For example if cutoff dev hda3 50 is specified diskcheck will alert the system administrator when the partition dev hda3 reaches 50 capacity e cutoff mountpoint Override the defaultCutoff for the mount point For exam ple if cutoff home 50 is specified diskcheck will alert the system administrator when the mount point home reaches 50 capacity exclude Specify one or more partitions for diskcheck to ignore For example if ex clude dev sda2 dev sda4 is specified diskcheck will not alert the system ad ministrator if dev sda2 or dev sda4 reaches the specified cutoff percentage e ignore Specify one or more filesystem types to ignore in the format x filesystem type For example if ignore x nfs x iso9660 is specified the system adminis trator will not be alerted about nfs or iso9660 filesystems reaching capacity e mailTo Email address of the system administrator to alert when partitions and mount points reach the specified capacity For example ifmailTo webmaster example com is specified webmaster example com will be emailed alerts e mailFrom Specify the identity of the email sender This is useful if the system adminis trator wants to filter the mail from diskcheck For example ifmailFrom Disk Usage Monitor is specified email will be sent to the system admi
134. ds to the ServerAdmin directive in httpd conf If you configure the server s error pages to contain an email address this email address will be used so that users can report a problem by sending email to the server s administrator The default value is root localhost Use the Available Addresses area to define the ports on which Apache will accept incoming requests This option corresponds to the Listen directive in httpd conf By default Red Hat configures Apache to listen to port 80 for non secure Web communications Click the Add button to define additional ports on which to accept requests A window as shown in Figure 13 2 will appear Either choose the Listen to all addresses option to listen to all IP addresses on the defined port or specify a particular IP address over which the server will accept connections in the Address field Only specify one IP address per port number If you want to specify more than one IP address with the same port number create an entry for each IP address If at all possible use an IP address instead of a domain name to prevent a DNS lookup failure Refer to http httpd apache org docs dns caveats html for more information about Issues Regarding DNS and Apache Entering an asterisk in the Address field is the same as choosing Listen to all addresses Clicking the Edit button shows the same window as the Add button except with the fields populated for the selected entry To delete an entry select it and click
135. e The Common UNIX Printing System CUPS and the CUPS logo are the trademark property of Easy Software Products CUPS is copyright 1997 2002 by Easy Software Products All Rights Reserved 5 J Figure 21 18 CUPS Configuration Tool To add a printer click Manage Printers and then click the Add Printer button For more information click the Help button 21 12 Additional Resources To learn more about printing on Red Hat Linux refer to the following resources 21 12 1 Installed Documentation e man printcap The manual page for the etc printcap printer configuration file e map lpr The manual page for the 1pr command that allows you to print files from the command line man lpd The manual page for the LPRng printer daemon man lprm The manual page on the command line utility to remove print jobs from the LPRng spool queue man mpage The manual page on the command line utility to print multiple pages on one sheet of paper man cupsd The manual page for the CUPS printer daemon man cupsd conf The manual page for the CUPS printer daemon configuration file man classes conf The manual page for the class configuration file for CUPS 196 Chapter 21 Printer Configuration 21 12 2 Useful Websites e http www linuxprinting org GNU Linux Printing contains a large amount informa tion about printing in Linux http www cups org Documentation FAQs and newsgroups a
136. e file Cee Do not remove the localhost entry 84 Chapter 6 Network Configuration Devices Hardware Hosts DNS You may specify static computer hostname to IP address mappings here If DNS is in use these settings will take precedence over any information it may provide IP Name Aliases Add Edit 172 16 56 53 ijin devel redhat com Eat Delete Help Apply X Close Figure 6 14 Hosts Configuration rip To change lookup order edit the etc host conf file The line order hosts bind specifies that the etc hosts takes precedence over the name servers Changing the line to order bind hosts configures your system to resolve hostnames and IP addresses using the name servers first If the IP address can not be resolved through the name servers your system looks for the IP address in the etc hosts file 6 10 Managing DNS Settings The DNS tab allows you to configure the system s hostname domain name servers and search domain Name servers are used to look up other hosts on the network Devices Hardware Hosts ONS Hostname example redhat com Domain Primary DNS 172 116 48 1 Secondary DNS 172 16 48 2 Tertiary DNS DNS Search Path Domain Name Edit co Delete A Up V Down Search Domain ydd PHep vay x close Figure 6 15 DNS Configuration Chapter 6 Network Configuration
137. e from VeriSign and you are changing your server software VeriSign is a widely used CA If you already have a VeriSign certificate for another purpose you may have been considering using your existing VeriSign certificate with your new secure Web server However you will not be allowed to because VeriSign issues certificates for one particular server software and IP address domain name combination If you change either of those parameters for example if you previously used another secure Web server product and now you want to use the secure Web server the VeriSign certificate you obtained to use with the previous configuration will not work with the new configuration You will need to obtain a new certificate If you have an existing key and certificate that you can use you will not have to generate a new key and obtain a new certificate However you may need to move and rename the files which contain your key and certificate Move your existing key file to etc httpd conf ssl key server key Move your existing certificate file to etc httpd conf ssl crt server crt After you have moved your key and certificate skip to Section 14 9 If you are upgrading from the Red Hat Secure Web Server versions 1 0 and 2 0 your old key httpsd key and certificate httpsd crt will be located in etc httpd conf You will need to move and rename your key and certificate so that the secure Web server can use them Use the following two commands t
138. e in Figure 22 1 anacron for Red Hat Linux is configured to make sure the daily weekly and monthly cron tasks are run 22 2 2 Starting and Stopping the Service To start the anacron service use the command sbin service anacron start To stop the service use the command sbin service anacron stop It is recommended that you start the service at boot time Refer to Chapter 8 for details on starting the anacron service automatically at boot time 22 3 At and Batch While cron and anacron are used to schedule recurring tasks the at command is used to schedule a one time task at a specific time The bat ch command is used to schedule a one time task to be executed when the systems load average drops below 0 8 To use at or batch you must have the at RPM package installed and the ata service must be running To determine if the package is installed use the rpm q at command To determine if the service is running use the command sbin service atd status 22 3 1 Configuring At Jobs To schedule a one time job at a specific time type the command at time where time is the time to execute the command The argument t ime can be one of the following e HH MM format For example 04 00 specifies 4 00AM If the time is already pasted it is executed at the specified time the next day e midnight Specifies 12 00AM e noon Specifies 12 00PM Chapter 22 Automated Tasks 201 teatime Specifies 4 00PM month name day y
139. e information for the authentication method 50 Chapter 2 Kickstart Configurator 2 7 Firewall Configuration File Help Firewall Configuration Basic Configuration Boot Loader Options Installation Method Partition Information Network Configuration Authentication Customize Firewall Configuration Use default firewall rules Security Level C High Medium C Disabled X Configuration Package Selection C Customize Pre Installation Script Post Installation Script Trusted device Allow incoming Save File X Cancel Help Figure 2 8 Firewall Configuration The Firewall Configuration window is identical to the screen in the Red Hat Linux instal lation program and provides the same functionality Choose between High Medium and Disabled security levels Refer to the Official Red Hat Linux Installation Guide for detailed information about these security levels 2 8 X Configuration If you are installing the X Window System you can configure it during the kickstart in stallation by checking the Configure the X Window System button on the X Configuration window as shown in Figure 2 9 If this option is not chosen the X configuration options will be disabled and the skipx option will be written to the kickstart file Chapter 2 Kickstart Configurator 51 2 8 1 General File Help X Configuration Basic Con
140. e parameters that can be used with them 9 4 2 Useful Websites e http www openssh com The OpenSSH FAQ page bug reports mailing lists project goals and a more technical explanation of the security features http www openssl org The OpenSSL FAQ page mailing lists and a description of the project goal http www freessh org SSH client software for other platforms reana Chapter 10 Network File System NFS Network File System NFS is a way to share files between machines on a network as if the files were located on the client s local hard drive Red Hat Linux can be both an NFS server and an NFS client which means that it can export filesystems to other systems and mount filesystems exported from other machines 10 1 Why Use NFS NFS is useful for sharing directories of files between multiple users on the same network For example a group of users working on the same project can have access to the files for that project using a shared directory of the NFS filesystem commonly known as an NFS share mounted in the directory myproject To access the shared files the user goes into the myproject directory on his machine There are no passwords to enter or special commands to remember Users work as if the directory is on their local machines 10 2 Mounting NFS Filesystems Use the mount command to mount an NFS filesystem from another machine mount shadowman example com mnt export mnt local
141. e probably will not run correctly use the nodeps option 25 2 3 Uninstalling Uninstalling a package is just as simple as installing one Type the following command at a shell prompt rpm e foo rote Notice that we used the package name foo not the name of the original package file foo 1 0 1 i386 rpm To uninstall a package you will need to replace foo with the actual package name of the original package You can encounter a dependency error when uninstalling a package if another installed package depends on the one you are trying to remove For example rpm e foo removing these packages would break dependencies foo is needed by bar 1 0 1 To cause RPM to ignore this error and uninstall the package anyway which is also a bad idea since the package that depends on it will probably fail to work properly use the nodeps option 25 2 4 Upgrading Upgrading a package is similar to installing one Type the following command at a shell prompt rpm Uvh foo 2 0 1 i386 rpm foo Hae a HH IE IE IE AE FE AE a a E a AE AE EHH FE AE AE aR aR EH HH HH E What you do not see above is that RPM automatically uninstalled any old versions of the foo package In fact you may want to always use u to install packages since it will work even when there are no previous versions of the package installed Since RPM performs intelligent upgrading of packages with configuration files you may see a message like the follo
142. e proper architecture for the kernel kernel smp and kernel bigmem packages Use the i386 versions of the other packages Chapter 23 Ugrading the Kernel 207 23 3 Downloading the Upgraded Kernel There are several ways to determine if there is an updated kernel available for your system Go to http www redhat com apps support errata choose the version of Red Hat Linux you are using and view the errata for it Kernel errata are usually under the Security Advisories section From the list of errata click the kernel errata to view the detailed errata report for it In the errata report there is a list of required RPM packages and a link to download them from the Red Hat FTP site You can also download them from a Red Hat FTP mirror site A list of mirror sites is available at http www redhat com download mirror html Use Red Hat Network You can use Red Hat Network to download the kernel RPM pack ages and then manually upgrade to the latest kernel Or if you have elected to let the Red Hat Update Agent upgrade packages for you Red Hat Network can download the lastest kernel upgrade the kernel on your system create an initial RAM disk if needed and con figure the boot loader to boot the new kernel All you have to do is reboot into the new kernel For more information refer to the Red Hat Network User Reference Guide available at http www redhat com docs manuals RHNetwork If there is an updated kernel for the version of Red Ha
143. e the file etc hosts 1pa on the remote machine to which the printer is attached On separate lines in the file add the IP address or hostname of each machine which should have printing privileges 21 3 Adding a Samba SMB Printer To add printer which is accessed using the SMB protocol click the New button in the main printconf window The window shown in Figure 21 2 will appear Click Next to proceed You will see the screen shown in Figure 21 7 Enter a unique name for the printer in the Queue Name text field The printer name cannot contain spaces and must begin with a letter a through z or A through Z The valid characters are a through z A through zZ 0 through 9 and _ Select Windows Printer from the Queue Type menu and click Next If the printer is attached to a Microsoft Windows system choose this queue type Set the Print Queue Name and Type Enter the Queue s name and select the Queue s Type Valid names can contain the characters a z A Z 0 9 and _ They must begin with letters Queue Name test3 Queue Type C Local Printer LOCAL C Unix Printer LPD Windows Printer C Novell Printer NCP C JetDirect Printer JETDIRECT Che gt Next X amp Cancel Figure 21 7 Adding a SMB Printer Text fields for the following options appear as shown in Figure 21 8 e Share The name of the shared printer on which you want to print This name must be the same name defined as the Samb
144. e top of the window You can choose to keep the existing partitions remove all the existing partitions or remove all the existing Linux partitions by selecting None All or Linux respectively next to Remove Partitions Chapter 2 Kickstart Configurator 47 You can initialize the disk label to the default for the architecture of the system msdos for x86 and gpt for Itanium Choose Yes if you are installing on a brand new hard drive 2 4 1 Creating Partitions To create a partition click the Add button The Partition Options window shown in Figure 2 5 will appear Choose mount point filesystem type and partition size for the new partition Optionally you can also choose from the following Additional Size Options Choose to make the partition a fixed size up to a chosen size or fill the remaining space on the hard drive Force the partition to be created as a primary partition Create the partition on a specific hard drive For example to make the partition on the first IDE hard disk dev hda specify hda as the drive Do not include dev in the drive name Use an existing partition For example to make the partition on the first partition on the first IDE hard disk dev hda1 specify hda1 as the partition Do not include dev in the partition name Format the partition as the chosen filesystem type Mount Paint Filesystem Type ext3 i L Le Size MB 2046 Additional Size Options C Fixed
145. eady installed If you want to install the package anyway and the same version you are trying to install is already installed you can use the replacepkgs option which tells RPM to ignore the error rpm ivh replacepkgs foo 1 0 1 i386 rpm foo FEE AE FE FE E AE AE FE FE EH RE FE FE AE FE FE AE FE E FE AE FE AE FE AE AE REE This option is helpful if files installed from the RPM were deleted or if you want the original configuration files from the RPM to be installed 25 2 2 2 Conflicting Files If you attempt to install a package that contains a file which has already been installed by another package or an earlier version of the same package you will see rpm ivh foo 1 0 1 i386 rpm foo usr bin foo conflicts with file from bar 1 0 1 To make RPM ignore this error use the replacefiles option rpm ivh replacefiles foo 1 0 1 i386 rpm foo E AE aa aR E AE FE AE FE AE FE AE EH aR AE HE FE EAE AR RE BE 25 2 2 3 Unresolved Dependency RPM packages can depend on other packages which means that they require other pack ages to be installed in order to run properly If you try to install a package which has an unresolved dependency you will see rpm ivh foo 1 0 1 i386 rpm 220 Chapter 25 Package Management with RPM failed dependencies bar is needed by foo 1 0 1 To handle this error you should install the requested packages If you want to force the installation anyway a bad idea since the packag
146. ear format For example January 15 2002 specifies the 15th day of January in the year 2002 The year is optional MMDDYY MM DD YY or MM DD YY formats For example 011502 for the 15th day of January in the year 2002 now time time is in minutes hours days or weeks For example now 5 days specifies that the command should be executed at the same time in five days The time must be specified first followed by the optional date For more information about the time format read the usr share doc at lt version gt timespec text file After typing the at command with the time argument the at gt prompt is displayed Type the command to execute press Enter and type Ctrl D More than one command can be spec ified by typing each command followed by the Enter key After typing all the commands press Enter to go to a blank line and type Ctrl D Alternatively a shell script can be entered at the prompt pressing Enter after each line in the script and typing Ctrl D on a blank line to exit If a script is entered the shell used is the shell set in the user s SHELL environment the user s login shell or bin sh whichever is found first If the set of commands or script tries to display information to standard out the output is emailed to the user Use the command atq to view pending jobs Refer to Section 22 3 3 for more information Usage of the at command can be restricted Refer to Section 22 3 5 for details
147. eate a boot diskette for your system Login as root at a shell prompt and type the following command where kernelversion is the output of the uname r command sbin mkbootdisk kernelversion 206 Chapter 23 Ugrading the Kernel rip Refer to the man page for mkboot disk for more options Reboot your machine with the boot diskette and verify that it works before continuing Hopefully you will not have to use the diskette but you should store it in a safe place just in case To determine which kernel packages you have installed execute the following command at a shell prompt rpm qa grep kernel The output will contain some or all of the following packages depending on what type of installation you performed your version numbers and packages may differ kernel utils 2 4 18 0 12 kernel 2 4 18 0 12 kernel source 2 4 18 0 12 kernel doc 2 4 18 0 12 kernel pemcia cs 3 1 27 12 kernel smp 2 4 18 0 12 From the output you can determine which packages you need to download for the kernel upgrade For a single processor system the only required package is the kernel package If you have a computer with more than one processor you need the kernel smp package that contains support for multiple processors It is recommended that you also install the kernel package in case the multi processor kernel does not work properly for your system If you have a computer with more than four gigabytes of memory you need the kernel bigme
148. eb server and identifies the secure server to client Web browsers You must purchase your own digital certificate Do not use the dummy one provided in Red Hat Linux for your website For details on purchasing a CA approved digital certificate refer to the Chapter 14 132 Chapter 13 Apache Configuration General Options r Enable SSL support Site Configuration SSL Configuration i Logging Certificate File retcrnttpd contissl crvserver crt A Browse Environment Variables Directories Certificate Key File fetcenttpa contissl key server key 4 Browse Certificate Chain File retcrntiparcont ssl crvca crt 4 Browse Certificate Authority File Ptcrhttpd cont ss crl ca bundle ct Browse SSL Log File flogs ssi_engine_log Browse SSL Log Level Infa ZA 55L Options O FakeBasicAuth C ExportCertData C CompatEnvVars O StrictRequire C OptRenegotiate oK X Cancel Help Figure 13 12 SSL Support 13 3 1 3 Additional Virtual Host Options The Site Configuration Environment Variables and Directories options for the virtual hosts are the same directives that you set when you clicked the Edit Default Settings button except the options set here are for the individual virtual hosts that you are configuring Refer to Section 13 2 for details on these options 13 4 Server Settings The Server tab allows you to configure basic server settings The default settings for these options are
149. ed Hat Linux CD ROM Gnome RPM will search in mnt cdrom RedHat RPMS for new packages You can change the default path in the Install Window tab of the Operations gt Preferences dialog See Section 26 4 for more information If no packages are available in the default path you will see an Add Packages window You can select the location of your new package using the standard file dialog window If you click on a package you will see a brief description of the package in the Package Info panel of the Install window To perform an installation or a query on the package select the check box next to the package then click on the Install button You can also query a selected package On the Package Info window you can also perform the installation To choose an item double click on it with your left mouse button or click on the Add button The selected package s will be added to the Install window In addition to installing the packages from within the Install window you can install a pack age after performing a query on the selected package Click on Query which will open the Package Info window Here you can find a variety of details about the package you have selected to install including the origination of the package the date it was built its size and more If the package already exists on your system and you are querying a newer version the Package Info window provides an Upgrade button which will upgrade the package to the
150. ee the Official Red Hat Linux Reference Guide for more information about iptables Alternatively if you are looking for a utility which will set general access rules for your home machine and or if you are new to Linux you should try the GNOME Lokkit utility GNOME Lokkit is a GUI utility which will ask you questions about how you want to use your machine Based on your answers it will then configure a simple firewall for you Refer to Chapter 7 for more information 8 1 Runlevels Before you can configure access to services you must understand Linux runlevels A runlevel is a state or mode that is defined by the services listed in the directory etc rce d rc lt x gt d where lt x gt is the number of the runlevel Red Hat Linux uses the following runlevels 92 Chapter 8 Controlling Access to Services 0 Halt 1 Single user mode 2 Not used user definable 3 Full multi user mode e 4 Not used user definable e 5 Full multi user mode with an X based login screen e 6 Reboot If you configured the X Window System during the Red Hat Linux installation program you had the option of choosing a graphical or text login screen If you chose a text login screen you are operating in runlevel 3 If you chose a graphical login screen you are operating in runlevel 5 The default runlevel can be changed by modifying the etc inittab file which contains a line near the top of the file similar to the followin
151. ely The files in these direc tory should be shell scripts If a cron tasks needs to be executed on a schedule other than hourly daily weekly or monthly it can be added to the etc cron d directory All files in this directory use the same syntax as etc crontab Users other than root can configure cron tasks by using the crontab utility All user defined crontabs are stored in the var spool cron directory and are executed using the usernames of the users that created them To create a crontab as a user login as that user and type the command crontab e to edit the user s crontab using the editor specified by the VISUAL or EDITOR environment variable The file uses the same format as etc crontab When the changes to the crontab are saved the crontab is stored according to username and written to the file var spool cron username The cron daemon checks the etc crontab file the etc cron d directory and the var spool cron directory every minute for any changes If any changes are found they are loaded into memory Thus the daemon does not need to be restarted if a crontab file is changed Chapter 22 Automated Tasks 199 22 1 2 Controlling Access to Cron The etc cron allow and etc cron deny files are used to restrict access to cron The format of both access control files is one username on each line Whitespace is not permitted in either file The cron daemon crond does not have to be restarted if the access control files a
152. emember to sign up for the benefits you are entitled to as a Red Hat customer You will be entitled to any or all of the following benefits depending upon the Official Red Hat Linux product you purchased Official Red Hat support Get help with your installation questions from Red Hat Inc s support team e Red Hat Network Easily update your packages and receive security notices that are customized for your system Go to http rhn redhat com for more details e Under the Brim The Official Red Hat E Newsletter Every month get the latest news and product information directly from Red Hat To sign up go to http www redhat com apps activate You will find your Product ID on a black red and white card in your Official Red Hat Linux box To read more about technical support for Official Red Hat Linux refer to the Getting Technical Support Appendix in the Official Red Hat Linux Installation Guide Good luck and thank you for choosing Red Hat Linux The Red Hat Documentation Team Installation Related Reference 3 hat redhat Chapter 1 Kickstart Installations 1 1 What are Kickstart Installations Many system administrators would prefer to use an automated installation method to install Red Hat Linux on their machines To answer this need Red Hat created the kickstart instal lation method Using kickstart a system administrator can create a single file containing the answers to all the questions that would
153. er should be LILO or GRUB append Specifies kernel parameters location Specifies where the boot record is written Valid values are the following mbr the default partition installs the boot loader on the first sector of the partition containing the kernel or none do not install the boot loader password mypassword If using GRUB sets the GRUB boot loader password to mypassword This should be used to restrict access to the GRUB shell where arbitrary kernel options can be passed md5pass mypassword If using GRUB similar to password except mypassword should be the password already encrypted useLilo Use LILO instead of GRUB as the boot loader 22 Chapter 1 Kickstart Installations linear If using LILO use the linear LILO option this is only for backwards compatibility and linear is now used by default nolinear If using LILO use the nolinear LILO option linear is the default 1lba32 If using LILO force use of lba32 mode instead of autodetecting upgrade 4 Upgrade the existing boot loader configuration This option is only available for upgrades 1 4 4 clearpart clearpart optional Removes partitions from the system prior to creation of new partitions By default no partitions are removed linux Erases all Linux partitions sall Erases all partitions from the system drives Specifies which drives to clear partitions from initlabel Initializes
154. er way 25 3 Checking a Package s Signature If you wish to verify that a package has not been corrupted or tampered with examine only the md5sum by typing the following command at a shell prompt replace coolapp with the filename of your RPM package rpm checksig nogpg coolapp 1 1 1 rpm You will see the message coolapp 1 1 1 rpm md5 OK This brief message means that the file was not corrupted by the download On the other hand how trustworthy is the developer who created the package If the pack age is signed with the developer s GnuPG key you will know that the developer really is who they say they are An RPM package can be signed using Gnu Privacy Guard or GnuPG to help you make certain your downloaded package is trustworthy GnuPG is a tool for secure communication it is a complete and free replacement for the encryption technology of PGP an electronic privacy program With GnuPG you can au thenticate the validity of documents and encrypt decrypt data to and from other recipients GnuPG is capable of decrypting and verifying PGP 5 x files as well During the installation of Red Hat Linux GnuPG is installed by default That way you can immediately start using GnuPG to verify any packages that you receive from Red Hat First you will need to import Red Hat s public key 224 Chapter 25 Package Management with RPM 25 3 1 Importing Keys When you import a public key you add that key to your keyring a fi
155. ese commands To read the man page execute the command man sftp at a shell prompt The sftp utility is only available in OpenSSH version 2 5 0p1 and higher 9 3 4 Generating Key Pairs If you do not want to enter your password every time you use ssh scp or sftp to connect to a remote machine you can generate an authorization key pair Keys must be generated for each user To generate keys for a user follow the following steps as the user who wants to connect to remote machines If you complete the following steps as root only root will be able to use the keys Bika Starting with OpenSSH version 3 0 ssh authorized_keys2 ssh known_hosts2 and etc ssh_known_hosts2 are obsolete SSH Protocol 1 and 2 share the ssh authorized_keys ssh known_hosts and etc ssh ssh_known_hosts files 9 3 4 1 Generating a DSA Key Pair for Version 2 Use the following steps to generate a DSA key pair for version 2 of the SSH Protocol 1 To generate a DSA key pair to work with version 2 of the protocol type the following command at a shell prompt ssh keygen t dsa Accept the default file location of ssh id_dsa Enter a passphrase different from your account password and confirm it by entering it again rip A passphrase is a string of words and characters used to authenticate a user Passphrases differ from passwords in that you can use spaces or tabs in the passphrase Passphrases are generally longer than passwords because they a
156. etwork for example a printer attached to a Microsoft Windows ma chine In the main printer list as shown in Figure 21 1 the Queue Type for a remote Windows printer is set to SMB Novell Printer NCP Queue a printer attached to a different system which uses Nov ell s NetWare network technology In the main printer list as shown in Figure 21 1 the Queue Type for a remote Novell printer is set to NCP JetDirect Printer a printer connected directly to the network instead of to a computer In the main printer list as shown in Figure 21 1 the Queue Type for a JetDirect printer is set to JETDIRECT iscsi If you add a new print queue or modify an existing one you need to restart the printer daemon 1pa for the changes to take effect Clicking the Apply button saves any changes that you have made and restarts the printer daemon The changes are not written to the etc printcap configuration file until the printer daemon 1pdq is restarted Alternatively you can choose File gt Save Changes and then choose File gt Restart lpd to save your changes and then restart the printer daemon If a printer appears in the main printer list with the Queue Type set to INVALID the printer configuration is missing options that are required for the printer to function properly To remove this printer from the list select it from the list and click the Delete button Chapter 21 Printer Configuration 181 21 1 Adding a Local Printer To
157. evices tab 2 Click the Add button 3 Select Ethernet connection from the Device Type list and click Next 4 If you have already added the network interface card to the hardware list select it from the Ethernet card list Otherwise select Other Ethernet Card to add the hardware device rote The installation program usually detects supported Ethernet devices and prompts you to con figure them If you configured any Ethernet devices during the installation they will already appear in the hardware list on the Hardware tab 5 If you selected Other Ethernet Card the Select Ethernet Adapter window appears Select the manufacturer and model of the Ethernet card Select the device name If this is the system s first Ethernet card select eth0 as the device name if this is the second Ethernet card select eth1 and so on The Network Administration Tool also allows you to configure the resources for the NIC Click Next to continue 6 On the Configure Network Settings page as shown in Figure 6 1 choose between DHCP and a static IP address You may also specify a hostname for the device If the device receives a different IP address each time the network is started do not specify a hostname Click Next to continue Configure Network Settings Hostname optional Automatically obtain IP address settings with dhcp C Statically set IP addresses Manual IP Address Settings Address subnet Mask Default Gat
158. eway Address lt Back D Next X Cancel EES Figure 6 1 Ethernet Settings 7 Click Finish on the Create Ethernet Device page Chapter 6 Network Configuration 75 After configuring the Ethernet device it appears in the device list as shown in Figure 6 2 Devices Hardware Hosts DNS ja You may configure network devices associated 4 with physical hardware here Multiple logical devices can be associated with a single piece of hardware Status Device Nickname Type Add Edit Copy Delete Activate Monitor i Eie EE P Hep Y apy Figure 6 2 Ethernet Device Be sure to click Apply to save the changes After adding the Ethernet device you can edit its configuration by selecting the device from the device list and clicking Edit For example when the device is added it is configured to start at boot time by default You can edit its configuration to modify this setting When the device is added it is not activated as seen by its Inactive status To activate the device select it from the device list and click the Activate button 6 3 Establishing an ISDN Connection An ISDN connection is an Internet connection established with a ISDN modem card through a special phone line installed by the phone company ISDN connections are popular in Eu rope To add an ISDN connection follow these steps 1 Click the Devices tab 2 Click the Add button 3 Sele
159. example if your HTTP server is server example com and the kickstart file is in the HTTP directory mydir ks cfg the correct boot command would be ks http server example com mydir ks cfg ks floppy The installation program looks for the file ks cfg on a vfat or ext2 filesystem on the floppy in drive dev fd0 Chapter 1 Kickstart Installations 41 ks hd lt device gt lt file gt The installation program will mount the filesystem on lt device gt which must be vfat or ext2 and look for the kickstart configuration file as lt file gt in that filesystem for example ks hd sda3 mydir ks cfg ks file lt file gt The installation program will try to read the file lt file gt from the filesystem no mounts will be done This is normally used if the kickstart file is already on the initrd image ks cdrom lt path gt The installation program will look for the kickstart file on CD ROM as file lt path gt ks If ks is used alone the installation program will configure the Ethernet card in the sys tem using DHCP The system will use the bootServer from the DHCP response as an NFS server to read the kickstart file from by default this is the same as the DHCP server The name of the kickstart file is one of the following If DHCP is specified and the bootfile begins with a the bootfile provided by DHCP is looked for on the NFS server If DHCP is specified and the bootfile begins with something other then a
160. f Error Code 400 Bad Request Default Error Page Footer Show footer with email address 9 _4 ox wee o Figure 13 3 Site Configuration The entries listed in the Directory Page Search List define the DirectoryIndex directive The DirectoryIndex is the default page served by the server when a user requests an index of a directory by specifying a forward slash at the end of the directory name For example when a user requests the page http your_domain this_directory they are going to get either the DirectoryIndex page if it exists or a server generated di rectory list The server will try to find one of the files listed in the Direct oryIndex directive and will return the first one it finds If it does not find any of these files and if options Indexes is set for that directory the server will generate and return a list in HTML format of the subdirectories and files in the directory Use the Error Code section to configure Apache to redirect the client to a local or external URL if the event of a problem or error This option corresponds to the ErrorDocument direc tive If a problem or error occurs when a client tries to connect to the Apache Web server the default action is to display the short error message shown in the Error Code column To override this default configuration select the error code and click the Edit button Choose Default to display the default short error message Choose URL to redirect the client to a
161. figuration Boot Loader Options IZ Configure the X Window System Installation Method Partition Information General Video Card Monitor Network Configuration Authentication Color Depth Resolution Firewall Configuration fe z 640x480 z Package Selection Pre Installation Script Default Desktop GNOME C KDE Post Installation Script Start the X Window System on boot X Cancel Help Save File Figure 2 9 X Configuration General The first step in configuring X is to choose the default color depth and resolution Select them from their respective pulldown menus Be sure to specify a color depth and resolution that is compatible with the video card and monitor for the system If you are installing both the GNOME and KDE desktops you need to choose which desktop you want to be the default If you are just installing one desktop be sure to choose it Once the system is installed users can choose which desktop they want to be their default For more information about GNOME and KDE refer to the Official Red Hat Linux Installation Guide and the Official Red Hat Linux Getting Started Guide Next choose whether to start the X Window System when the system is booted This op tion will start the system in runlevel 5 with the graphical login screen After the system is installed this can be changed by modifying the etc inittab configuration file 2 8 2 Video Card Probe for vi
162. find option to search the Internet for newly released packages You can direct Gnome RPM to search for particular distributions when you want to look for new packages If you have a slow connection this option can take some time to fully execute See Section 26 4 for more information about this feature A warning Be careful when using Web find since there is no way to verify the integrity of the many packages which are available at numerous repositories Before installing packages you should perform a query on that package to help you determine whether it can be trusted Packages not produced by Red Hat are not supported in any way by Red Hat Refer to Section 26 5 2 to learn more about verifying packages Using Gnome RPM to perform all of these and many other operations is the same as us ing RPM commands from the shell prompt However the graphical nature of Gnome RPM 230 Chapter 26 Gnome RPM may make these operations easier to perform Gnome RPM can display packages in a vari ety of different ways Refer to Section 26 3 for more information on using filters to identify packages You can install upgrade or uninstall several packages with a few button clicks Similarly you can query and verify more than one package at a time Since Gnome RPM is integrated with GNOME you can also perform installation query and verification on packages from within the GNOME File Manager If you want to maintain official Red Hat Linux packages it
163. formatted list of the directory s contents if no DirectoryIndex such as index html exists in the requested directory Multiview Support content negotiated multiviews this option is disabled by default SymLinksIfOwnerMatch Only follow symbolic links if the target file or directory has the same owner as the link To specify options for specific directories click the Add button beside the Directory list box The window shown in Figure 13 7 appears Enter the directory to configure in the Directory text field at the bottom of the window Select the options in the right hand list and configure the Order directive with the left hand side options The Order directive controls the order in which allow and deny directives are evaluated In the Allow hosts from and Deny hosts from text field you can specify one of the following e Allow all hosts Type a11 to allow access to all hosts Partial domain name Allow all hosts whose names match or end with the specified string Chapter 13 Apache Configuration 127 Full IP address Allow access to a specific IP address e A subnet Such as 192 168 1 0 255 255 255 0 e A network CIDR specification such as 10 3 0 0 16 Order Options w Let all hosts access this directory w Process Deny list before Allow list T FollowSymLinks i C Includes A Process Allow list before Deny list C includesNOEXEC 7 V Indexes DENM EISI 1 O Muttiviews A Den
164. g id 3 initdefault Change the number in this line to the desired runlevel The change will not take effect until you reboot the system To change the runlevel immediately use the command telinit followed by the runlevel number You must be root to use this command 8 2 TCP Wrappers Many UNIX system administrators are accustomed to using TCP wrappers to manage ac cess to certain network services Any network services managed by xinetd as well as any program with built in support for libwrap can use TCP wrappers to manage access xinetd can use the etc hosts allow and etc hosts deny files to configure access to system services As the names imply hosts allow contains a list of rules clients allowed to access the network services controlled by xinetd and hosts deny contains rules to deny access The hosts allow file takes precedence over the hosts deny file Permissions to grant or deny access can be based on individual IP address or hostnames or on a pattern of clients See the Official Red Hat Linux Reference Guide and the host s_access man page for details 8 2 1 xinetd To control access to Internet services use xinetd which is a secure replacement for inetd The xinetd daemon conserves system resources provides access control and logging and can be used to start special purpose servers xinetd can be used to provide access only to particular hosts to deny access to particular hosts to provide access to a service at certa
165. g Partition Information Network Configuration Authentication Firewall Configuration X Configuration Package Selection Type your pre script below T b j Save File X Cancel Help Figure 2 13 Pre Installation Script You can add commands to run on the system immediately after the kickstart file has been parsed and before the installation begins If you have configured the network in the kickstart file the network is enabled before this section is processed If you would like to include a pre installation script type it in the text area Efon Do not include the spre command It will be added for you Chapter 2 Kickstart Configurator 55 2 11 Post Installation Script File Help Post Installation Script Basic Configuration Boot Loader Options Warning An error in this script might cause your kickstart installation Installation Method to fail Do not include the post command at the beginning Partition Information Network Configuration Run outside of the chroot environment Authentication Firewall Configuration P Use an interpreter X Configuration Package Selection Type your post script below Pre Installation Script Post Installation Scrip Save File X Cancel Figure 2 14 Post Installation Script You can also add commands to execute on the system after the installation is completed If you have properly configured the network in the
166. g cable modem you should say no Yes lt Back ee amp Cancel 89 If you are using DHCP to activate any Ethernet interfaces on the system you must say Yes to the DHCP question If you say no you will not be able to establish a connect using the Ether net interface Many cable and DSL Internet providers require you to use DHCP to establish an Internet connection Figure 7 3 DHCP Are you using DHCP on any of your interfaces If you are then say yes and the firewall rules will allow DHCP clients to negotiate addresses with your provider gt Yes v No lt Back gt Next amp Cancel 7 4 Configuring Services GNOME Lokkit also allows you to turn common services on and off If you answer Yes to configuring services you are prompted about the following services 90 Chapter 7 Basic Firewall Configuration e Web Server Choose this option if you want people to connect to a Web server such as Apache running on your system You do not need to choose this option if you want to view pages on your own system or on other servers on the network Incoming Mail Choose this option if your system needs to accept incoming mail You do not need this option if you retrieve email using IMAP POP3 or fetchmail Secure Shell Secure Shell or SSH is a suite of tools for logging into and executing commands on a remote machine over an encrypted connection If you need to access your machine remotely
167. ge contains the OpenSSL toolkit The OpenSSL toolkit implements the SSL and TLS protocols and also includes a general purpose cryptography library mm The mm package contains the MM library which allows multiple instances of the httpd daemon to share state information Additionally other software packages included with Red Hat Linux can provide certain se curity functionalities but are not required by the secure server to function 138 Chapter 14 Apache Secure Server Configuration apache devel The apache devel package contains the Apache include files header files and the APXS utility You will need all of these if you intend to load any extra modules other than the modules provided with this product Please see the Official Red Hat Linux Reference Guide for more information on loading modules onto your secure Web server using Apache s DSO functionality If you do not intend to load other modules onto your Apache server you do not need to install this package apache manual The apache manual package contains the Apache Project s Apache 1 3 User s Guide in HTML format This manual is also available on the Web at http httpd apache org docs OpenSSH packages The OpenSSH packages provide the OpenSSH set of network connectivity tools for log ging into and executing commands on a remote machine OpenSSH tools encrypt all traffic including passwords so you can avoid eavesdropping connection hijacking and other attac
168. gt op at a shell prompt from within any X Window System desktop Then choose the Memory Usage tab File View Settings Windows Help aie Processes all Memory Usage resident Filesystems free Sum of oe CPU 9 16 user 3 59 system 5 14pm up 2 days loadavg 0 71 0 94 0 98 Figure 20 2 GNOME System Monitor 174 Chapter 20 Gathering System Information 20 3 Filesystems The df command reports the system s disk space usage If you type the command af at a shell prompt the output looks similar to the following Filesystem 1k blocks Used Available Use Mounted on dev hda2 10325716 2902060 6899140 30 dev hdal 15554 8656 6095 59 boot dev hda3 20722644 2664256 17005732 14 home By default this utility shows the partition size in 1 kilobyte blocks and the amount of used and available disk space in kilobytes To view the information in megabytes and gigabytes use the command df h The h argument stands for human readable format The output looks similar to the following Filesystem Size Used Avail Use Mounted on dev hda2 9 8G 2 8G 6 5G 30 dev hdal 15M 8 5M 5 9M 59 boot dev hda3 20G 2 6G 16G 14 home To view the system s disk space usage in a graphical format use the Filesystems tab in the GNOME System Monitor To start it on the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt System Monitor or type gtop at a shell pro
169. h the Samba username for the system Enter the correct password or press Enter if no password is required for the user If you see the smb gt prompt you have successfully logged in Once you are logged in type help for a list of commands If you wish to browse the contents of your home directory replace sharename with your username If the u switch is not used the username of the current user is passed to the Samba server To exit smbclient type exit at the smb gt prompt You can also use Nautilus to view available Samba shares on your network On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt Applications gt Nautilus to open a Nautilus window Type smb in the Location bar As shown in Figure 11 1 you will see an icon for each available SMB workgroups on your network To access one double click the icon for it File Edit View Go Bookmarks Preferences Help ar A Oo Ht aja Back Forward Up Refresh Home Web Search p 9 Location smb TOR View as Icons yy GER JHOME LINUX REDHAT smb folder 13 items amp RTP SUPPORT WORKGROUP News Notes Helpy History Figure 11 1 SMB Browser in Nautilus 110 Chapter 11 Samba If the SMB share you are connecting to requires a user name and password combination you must specify them in the Location bar using the following syntax replace user password servername and sharename with the appropriate values smb
170. hapter 26 Gnome RPM 231 Packages Operations Help aita Qa amp Install Unselect Uninstall Query Verify Find Web find Et Packages icone S SSS OS GS G 3 Applications Giarchiving emacs 20 emacs emacs el 20 emacs emacs aean D Communications 7 40 x11 20 7 40 leim 20 nox 20 7 40 7 40 7 40 Databases O Emutators BS Be amp amp amp amp Engineering s i 3 z x gnotepad ie jed jed xie joe psgml GFile i tepad 1 dO d d xjed 0 2 l1 313 99 14 2 common 0 99 14 2 36 1 21 13 Galnternet 99 14 2 Multimedia Productivity amp Be Be amp amp amp Publishing zj vim X11 5 vim vim vim minimal 5 xemacs 21 xemacs el 21 10 144410 Packages Selected 0 Figure 26 1 Main Gnome RPM Window 26 2 The Package Display Each folder icon in the tree view at left represents a group of packages Each group can contain subgroups For example the folder Applications contains the folder Editors that contains text editors such as Emacs ed vim and GXedit The tree view can be expanded and collapsed so you can easily navigate through the pack ages A folder which appears with a next to it indicates that there are subfolders within that category To expand a group into subgroups click once on the with your left mouse button To view the packages within the subgroup left click once on a folder name The display window will then show you the contents of that folder By default you will be presented with i
171. have an entry for an older kernel in lilo conf you had a problem If you would like to know a solution to this problem read this section In many cases you can boot your Red Hat Linux system from the Red Hat Linux boot disk with your root filesystem mounted and ready to go Here is how to do it Enter the following command at the boot disk s boot prompt linux single root dev hdxx initrd Replace the xx in dev hdxx with the appropriate letter and number for your root partition What does this command do First it starts the boot process in single user mode with the root partition set to your root partition The empty initrd specification bypasses the installation related image on the boot disk which will cause you to enter single user mode immediately Is there a negative side to using this technique Unfortunately yes Because the kernel on the Red Hat Linux boot disk only has support for IDE built in if your system is SCSI based you will not be able to do this In that case you will have to access rescue mode using the linux rescue command mentioned above 1 Tocreate an installation boot diskette insert a blank floppy disk and use the images boot img file on the Red Hat Linux CD ROM 1 with the command dd if boot img of dev fd0 3 redhat Chapter 4 Redundant Array of Independent Disks RAID 4 1 What is RAID The basic idea behind RAID is to combine multiple small inexpensive disk drives into an array to acc
172. he United States and other countries Linux is a registered trademark of Linus Torvalds Motif and UNIX are registered trademarks of The Open Group Intel and Pentium are a registered trademarks of Intel Corporation Itanium and Celeron are trademarks of Intel Corporation AMD AMD Athlon AMD Duron and AMD K6 are trademarks of Advanced Micro Devices Inc Netscape is a registered trademark of Netscape Communications Corporation in the United States and other countries Windows is a registered trademark of Microsoft Corporation SSH and Secure Shell are trademarks of SSH Communications Security Inc FireWire is a trademark of Apple Computer Corporation All other trademarks and copyrights referred to are the property of their respective owners The Red Hat Linux Product Documentation Team consists of the following people Sandra A Moore Product Documentation Manager Primary Writer Maintainer of the Official Red Hat Linux x86 Installation Guide Contributing Writer to the Official Red Hat Linux Getting Started Guide Tammy Fox Product Documentation Technical Lead Primary Writer Maintainer of the Official Red Hat Linux Customization Guide Contributing Writer to the Official Red Hat Linux Getting Started Guide Writer Maintainer of custom DocBook stylesheets and scripts Edward C Bailey Technical Writer Contributing Writer to the Official Red Hat Linux x86 Installation Guide Johnray Fuller Technical Writer Primary Writer
173. he Windows machines on your network To specify the Windows workgroup and description string edit the following lines in your smb conf file workgroup WORKGROUPNAME server string BRIEF COMMENT ABOUT SERVER Replace WORKGROUPNAME with the name of the Windows workgroup to which this machine should belong The BRIEF COMMENT ABOUT SERVERis optional and will be the Windows comment about the Samba system To create a Samba share directory on your Linux system add the following section to your smb conf file after modifying it to reflect your needs and your system sharename comment Insert a comment here path home share valid users tfox carole public no writable yes printable no create mask 0765 The above example allows the users tfox and carole to read and write to the directory home share on the Samba server from a Samba client 108 Chapter 11 Samba 11 2 1 Samba Passwords In Red Hat Linux 7 3 encrypted passwords are enabled by default because it is more secure If encrypted passwords are not used plain text passwords are used which can be intercepted by someone using a network packet sniffer It is recommended that encrypted passwords be used The Microsoft SMB Protocol originally used plaintext passwords However Windows 2000 and Windows NT 4 0 with Service Pack 3 or higher require encrypted Samba passwords To use Samba between a Red Hat Linux system and a system with Windows 2000 or Windows N
174. he comps file Architecture specific i386 ia64 alpha and sparc64 If a package name begins with an architecture type you only need to type in the package name not the architecture name For example For i386 apma you only need to use the apmd part for that specific package to be in stalled Lines beginning with Lines that begin with a are used by the installation program and should not be altered Lines beginning with hide If a package name begins with hide you only need to type in the package name without the hide For example For hide Network Server you only need to use the Network Server part for that specific package to be installed In most cases it is only necessary to list the desired components and not individual pack ages Note that the Base component is always selected by default so it is not necessary to specify it in the packages section Here is an example packages selection Spackages Network Managed Workstation Development Web Server X Window System ImageMagick As you can see components are specified one to a line starting with an symbol a space and then the full component name as given in the comps file Specify individual packages with no additional characters the ImageMagick line in the example above is an individual package You can also direct the kickstart installation to install the default packages for a workstation KDE or GNOME or server installa
175. he following The authenticity of host penguin example net can t be established DSA key fingerprint is 94 68 3a 3a bc f 3 9a 9b 01 5d b3 07 38 e2 11 0c Are you sure you want to continue connecting yes no Type yes to continue This will add the server to your list of known hosts as seen in the following message Warning Permanently added penguin example net DSA to the list of known hosts Next you ll see a prompt asking for your password for the remote machine After entering your password you will be at a shell prompt for the remote machine If you use ssh without any command line options the username that you are logged in as on the local client ma chine is passed to the remote machine If you want to specify a different username use the following command ssh l username penguin example net You can also use the syntax ssh username penguin example net The ssh command can be used to execute a command on the remote machine without log ging in to a shell prompt The syntax is ssh hostname command For example if you want to execute the command 1s usr share doc on the remote machine penguin example net type the following command at a shell prompt ssh penguin example net ls usr share doc After you enter the correct password the contents of usr share doc will be displayed and you will return to your shell prompt 9 3 2 Using the scp Command The scp command can be used to transfer files between machi
176. he kick start file is located on a boot diskette that was created from the boot img or bootnet img image file the correct boot command would be boot linux ks floppy The linux ks floppy command also works if the ks cfg file is located on a vfat or ext2 filesystem on a floppy diskette and you boot from the Red Hat Linux CD ROM An alternate boot command for booting off the Red Hat Linux CD ROM and having the kickstart file on a vfat or ext2 filesystem on a floppy diskette is boot linux ks hd fd0 ks cfg If you need to use a driver disk with kickstart you can still have the kickstart file on a floppy disk boot linux ks floppy dd The Red Hat Linux installation program looks for a kickstart file if the ks command line argument is passed to the kernel The command line argument can take a number of forms ks nfs lt server gt lt path gt The installation program will look for the kickstart file on the NFS server lt server gt as file lt path gt The installation program will use DHCP to configure the Ethernet card For example if your NFS server is server example com and the kickstart file is in the NFS share mydir ks cfg the correct boot command would be ks nfs server example com mydir ks cfg ks http lt server gt lt path gt The installation program will look for the kickstart file on the HTTP server lt server gt as file lt path gt The installation program will use DHCP to configure the Ethernet card For
177. he server key file after using it to create your certificate request your certificate will no longer work and the CA will not be able to help you Your only option would be to request and pay for a new certificate If you are going to purchase a certificate from a CA continue to Section 14 7 If you are generating your own self signed certificate continue to Section 14 8 14 7 Generating a Certificate Request to Send toa CA Once you have created a key the next step is to generate a certificate request which you will need to send to the CA of your choice Type in the following command make certreq Your system will display the following output and will ask you for your password unless you disabled the password option umask 77 usr bin openssl req new key etc httpd conf ssl key server key out etc httpd conf ssl csr server csr Using configuration from usr share ssl openssl cnf Enter PEM pass phrase 144 Chapter 14 Apache Secure Server Configuration Type in the password that you chose when you were generating your key Your system will display some instructions and then ask for a series of responses from you Your inputs will be incorporated into the certificate request The display with example responses will look like this You are about to be asked to enter information that will be incorporated into your certificate request What you are about to enter is what is called a Distinguished Name or a DN There
178. here Multiple logical z devices can be associated with a single piece of hardware Status Device Nickname Type Ada 5 Edit Copy Delete Activate Deactivate aj J gt Monitor 2 Hep Y anpy x Close Figure 6 13 Wireless Device Be sure to click Apply to save the changes After adding the wireless device you can edit its configuration by selecting the device from the device list and clicking Edit For example you can configure the device to activate at boot time When the device is added it is not activated as seen by its Inactive status To activate the device select if from the device list and click the Activate button 6 9 Managing Hosts The Hosts tab allows you to add edit or remove hosts from the etc hosts file This file contains IP addresses and their corresponding hostnames When your system tries to resolve a hostname to an IP address or determine the hostname for an IP address it refers to the etc hosts file before using the name servers if you are using the default Red Hat Linux configuration If the IP address is listed in the etc hosts file the name servers are not used If your network contains computers whose IP addresses are not listed in DNS it is recommended that you add them to the etc hosts file To add an entry to the etc hosts file click Add in the Hosts tab provide the requested information and click OK Click Apply to write the entry to th
179. hical interface for configuring a DHCP client refer to Chapter 6 for details on using Network Configurator to configure a network interface to use DHCP 1 Kudzu is a hardware probing tool run at system boot time to determine what hardware has been added or removed from the system Chapter 12 Dynamic Host Configuration Protocol DHCP 117 12 4 Additional Resources For configuration options not covered here please refer to the following resources 12 4 1 Installed Documentation hcpd man page describes how the DHCP daemon works d e dhcpd conf man page explains how to configure the DHCP configuration file includes some examples e dhcpd leases man page explains how to configure the DHCP leases file includes some examples dhcp options man page explains the syntax for declaring DHCP options in dhcpd conf includes some examples d hcrelay man page explains the DHCP Relay Agent and its configuration options 12 4 2 Useful Websites http www linuxdoc org HOWTO mini DHCP index html DHCP mini HOWTO from the Linux Documentation Project 118 Chapter 12 Dynamic Host Configuration Protocol DHCP redhat Chapter 13 Apache Configuration The Apache Configuration Tool allows you to configure the etc httpd conf httpd conf configuration file for your Apache Web server It does not use the old srm conf or ac cess conf configuration files leave them empty Through the graphical interface yo
180. hrase by entering it again The public key is written to ssh identity pub The private key is written to ssh identity Do not give anyone the private key 2 Change the permissions of your ssh directory and your key with the commands chmod 755 sshand chmod 644 ssh identity pub 3 Copy the contents of ssh identity pub to the file ssh authorized_keys on the machine to which you wish to connect If the file ssh authorized_keys does not exist you can copy the file ssh identity pub to the file ssh authorized_keys on the remote machine 4 If you are running GNOME skip to Section 9 3 4 4 If you are not running GNOME skip to Section 9 3 4 5 9 3 4 4 Configuring ssh agent with GNOME The ssh agent utility can be used to save your passphrase so that you do not have to enter it each time you initiate an ssh or scp connection If you are using GNOME the openssh askpass gnome utility can be used to prompt you for your passphrase when you log in to GNOME and save it until you log out of GNOME You will not have to enter your password or passphrase for any ssh or scp connection made during that GNOME session If you are not using GNOME refer to Section 9 3 4 5 To save your passphrase during your GNOME session follow the following steps 1 You ll need to have the package openssh askpass gnome installed you can use the command rpm q openssh askpass gnome to determine if it is installed or not If it is not ins
181. ice lt device gt Used to select a specific Ethernet device for installation Note that using device lt device gt will not be effective unless the kickstart file is a local file such as ks floppy since the installation program will configure the network to find the kickstart file Example network bootproto dhcp device eth0 pare ip IP address for the machine to be installed gateway Default gateway as an IP address nameserver Primary nameserver as an IP address nodns Do not configure any DNS server netmask Netmask for the installed system hostname Hostname for the installed system There are three different methods of network configuration DHCP e BOOTP e static The DHCP method uses a DHCP server system to obtain its networking configuration As you might guess the BOOTP method is similar requiring a BOOTP server to supply the networking configuration 30 Chapter 1 Kickstart Installations The static method requires that you enter all the required networking information in the kickstart file As the name implies this information is static and will be used during the installation and after the installation as well To direct a system to use DHCP to obtain its networking configuration use the following line network bootproto dhcp To direct a machine to use BOOTP to obtain its networking configuration use the fol lowing line in the kickstart file network
182. ideo card and monitor 1 4 28 zerombr Partition Table Initialization zerombr optional If zerombr is specified and yes is its sole argument any invalid partition tables found on disks are initialized This will destroy all of the contents of disks with invalid parti tion tables This command should be in the following format zerombr yes No other format is effective 1 4 29 tpackages Package Selection Use the packages command to begin a kickstart file section that lists the packages you would like to install this is for installations only as package selection during upgrades is not supported 36 Chapter 1 Kickstart Installations Use the tpackages resolvedeps to install the listed packages and automatically resolve package dependencies Use the packages ignoredeps to ignore the unresolved dependencies and install the listed packages without the dependencies Packages can be specified by component or by individual package name The installation program defines several components that group together related packages See the Red Hat base comps file on any Red Hat Linux CD ROM for a list of components The compo nents are defined by the lines that begin with a number followed by a space and then the component name Each package in that component is then listed line by line Individual packages lack the leading number found in front of component lines Additionally there are three other types of lines in t
183. ied for an upgrade those items will be ignored note that this includes package selection 1 4 Kickstart Options The following options can be placed in a kickstart file If you prefer to use a graphical in terface for creating your kickstart file you can use the Kickstart Configurator application Refer to Chapter 2 for details Chapter 1 Kickstart Installations 19 1 4 1 autostep autostep optional Similar to interactive except it goes to the next screen for you It is used mostly for debugging 1 4 2 auth auth or authconfig required Sets up the authentication options for the system It s similar to the authconfig com mand which can be run after the install By default passwords are normally encrypted and are not shadowed enablemd5 Use md5 encryption for user passwords enablenis Turns on NIS support By default enablenis uses whatever domain it finds on the network A domain should almost always be set by hand via nisdomain nisdomain NIS domain name to use for NIS services nisserver Server to use for NIS services broadcasts by default useshadow or enableshadow Use shadow passwords enableldap Turns on LDAP support in etc nsswitch conf allowing your system to retrieve information about users UIDs home directories shells etc from an LDAP direc tory To use this option you must have the nss_ldap package installed You must also specify a server a
184. igh example com hardware ethernet 00 A1 DD 74 C3 F2 fixed address 192 168 1 6 To configure a DHCP server that leases a dynamic IP address to a system within a subnet modify Example 12 4 with your values It declares a default lease time maximum lease time and network configuration values for the clients This example assigns IP addresses in the range 192 168 1 10 and 192 168 1 100 to client systems Example 12 4 Range Parameter default lease time 600 max lease time 7200 option subnet mask 255 255 255 0 option broadcast address 192 168 1 255 option routers 192 168 1 254 option domain name servers 192 168 1 1 192 168 1 2 option domain name example com subnet 192 168 1 0 netmask 255 255 255 0 range 192 168 1 10 192 168 1 100 To assign an IP address to a client based on the MAC address of the network interface card use the hardware ethernet parameter within a host declaration As demonstrated in Ex ample 12 5 the host apex declaration specifies that the network interface card with the MAC address 00 A0 78 8E 9E AA always receives the IP address 192 168 1 4 Notice that you can also use the optional parameter host name to assign a host name to the client 114 Chapter 12 Dynamic Host Configuration Protocol DHCP Example 12 5 Static IP Address using DHCP host apex option host name apex example com hardware ethernet 00 A0 78 8E 9E AA fixed address 192 168 1 4 rip You can use the sample
185. iguration Use the Log Level menu to set how verbose the error messages in the error logs will be It can be set from least verbose to most verbose to emerg alert crit error warn notice info or debug This option corresponds to the LogLevel directive The value chosen with the Reverse DNS Lookup menu defines the Host nameLookups direc tive Choosing No Reverse Lookup sets the value to off Choosing Reverse Lookup sets the value to on Choosing Double Reverse Lookup sets the value to double If you choose Reverse Lookup your server will automatically resolve the IP address for each connection which requests a document from your Web server Resolving the IP address means that your server will make one or more connections to the DNS in order to find out the hostname that corresponds to a particular IP address If you choose Double Reverse Lookup your server will perform a double reverse DNS In other words after a reverse lookup is performed a forward lookup is performed on the result At least one of the IP addresses in the forward lookup must match the address from the first reverse lookup Generally you should leave this option set to No Reverse Lookup because the DNS requests add a load to your server and may slow it down If your server is busy the effects of trying to perform these reverse lookups or double reverse lookups may be quite noticeable Reverse lookups and double reverse lookups are also an issue for the Internet as a
186. il Transport Agent MTA Configuration csccccsssscsssssnsvsusnsnsnensnenee 155 TIT System Configuration cscsesssssessssssscencssenssssesesessesssnssnssesseeacsssseesseacsncsnssssneenesseseeneeneeess 157 17 Console ACCESS sirsie eitie 17 1 Disabling Shutdown Via Ctrl Alt Del 17 2 Disabling Console Program Access 17 3 Disabling All Console Access 160 17 4 Defining the Console cccscesesceeeeees 160 17 5 Making Files Accessible From the Console 160 17 6 Enabling Console Access for Other Applications c cccscsceeseseseees 161 177 The Lopp y Group ss si ee aaea a R E O EE NEAS 162 18 Time and Date Configuration 163 18 1 Time and Date Properties 18 2 Time Zone Configuration 19 User and Group Configuration 19 1 Adding a New Uset 167 19 2 Modifying User Properties 168 19 3 Adding a New Group 169 19 4 Modifying Group Properties 20 Gathering System Information 20 1 System Processes 171 20 2 Memory Usage 20 3 Filesystems 173 20 4 Hard Ware secs Sevcesczsst aries ceca eesti an docs aston shh Lede A SEEE AOAIE 175 20 5 Additional Resources 00 eesesesseseseseeteeseseceseseeeecseseseecececeeeseeeeseeescneeeeeaeaes 176 21 Printer Configuration 0 179 21 1 Adding a Local Printer 180 21 2 Adding a Remote UNIX Printer 182 21 3 Adding a
187. ilar to the replacepkgs option from the shell prompt This option can be useful if an installed package has become damaged or requires repair to function correctly Allow replacement of files Allows the replacement of files which are owned by an other package The shell prompt equivalent for this RPM option is replacefiles This Chapter 26 Gnome RPM 235 option can be useful when two packages include files that are named the same but contain different contents Allow upgrade to old version Like the shell prompt RPM command equivalent oldpackage this option allows you to upgrade to an earlier package It can be useful if the latest version of a package does not function correctly on your system Keep packages made obsolete Prevents packages listed in an Obsoletes header from being removed In Other Options you can select Do not install documentation Like excludedocs this option can save on disk space by excluding documentation such as man pages or other information related to the pack age Install all files Installs all files in the package The choices available in Database Options and Architecture Options allow you to decide among other things whether you want to perform a test installation which will check for file conflicts without actually performing an install or whether you want to exclude packages for other operating systems or system architectures In the Package Listing tab you w
188. ile Records Add edit and delete record resources of type Host Alias and Name server Master Zone Name forward example com File Name forward example com zone i Contact root localhost Primary Name Server 50A je Serial Number 1 Set Time Settings e Records forward example cam il i A l ei Im 2 re Jelete Pox X Cancel ie Figure 15 2 Adding a Forward Master Zone The configuration shown in Figure 15 2 creates the following entry in etc named conf zone forward example com type master file forward example com zone It also creates the file var named forward example com zone with the following infor mation STTL 86400 IN SOA root localhost 1 serial 28800 refresh 7200 retry 604800 expire 86400 ttl After configuring the Forward Master Zone click OK to return to the main window as shown in Figure 15 1 From the pulldown menu choose File gt Apply to write the 152 Chapter 15 BIND Configuration etc named conf configuration file write all the individual zone files in the var named directory and have the daemon reload the configuration files 15 2 Adding a Reverse Master Zone To add a reverse master zone click the Add button and select Reverse Master Zone Enter the first three octets of the IP address range that you want to configure For example if you are configuring the IP address range 192 168 10 0 255 255 255
189. ill find a choice of displays for your packages either View as icons which will be graphically based or View as list which is not graphical but can provide more information about the packages In Install Window you can specify the path where Gnome RPM can find new RPMs on your system Refer to Figure 26 5 for an example of this dialog If you are using your Red Hat Linux CD ROM this path will probably be mnt cdrom RedHat RPMS If you download new RPMs from the Internet or want to install RPMs via a NFS mounted CD ROM this path will be different for you Behaviour Package Listing Install Window Network Rpmfind Distributions Package Colours Older Colour E Current Colour Hi Newer Colour Hil Default File Selection Dialog Path mnt cdrom RedHavRPMS _A Browse RPM Directories mnt cdrom RedHal RPMS P mntcdrom SRPMS mnticdrom RPMS fmntcdromis 6 oK Apply X Close 2 Help Figure 26 5 Install Window 236 Chapter 26 Gnome RPM To change this path type the full path to the RPMs you would like to work with Choosing the Apply or OK buttons will save this path making it the default path for future sessions You can also determine the default path by selecting the Browse button and visually navigating through the RPMPath window After changing the install path and closing the dialog box you can use the Install button to view the packages available in the new
190. imilar to mkbootdisk device dev fd0 2 4 x where 2 4 x is the full version of your ker nel such as 2 4 18 0 12 Once done test the boot disk to make sure that it will boot the system 2 You must have both the kernel headers and kernel source packages installed Is sue the commands rpm q kernel headers and rpm q kernel source to deter mine their versions if they are installed If they are not installed install them from the Red Hat Linux CD 1 or the Red Hat FTP site available at ftp ftp redhat com a list of mirrors is available at http www redhat com mirrors html Refer to Chapter 25 for information on installing RPM packages 3 Open a shell prompt and change to the directory usr src linux 2 4 All commands from this point forward must be executed from this directory 4 It is important that you begin a kernel build with the source tree in a known condition Therefore it is recommended that you begin with the command make mrproper This 248 Appendix A Building a Custom Kernel will remove any configuration files along with the remains of any previous builds that may be scattered around the source tree If you already have an existing configuration file that works usr src linux 2 4 config that you want to use back it up toa different directory before running this command and copy it back afterward If you use an existing configuration file skip the next step 5 Now you must create a configuration file that will dete
191. in times to limit the rate of incoming connections and or the load created by connections etc xinetd runs constantly and listens on all of the ports for the services it manages When a connection request arrives for one of its managed services xinetd starts up the appropriate server for that service The configuration file for xinetd is etc xinetd conf but you will notice upon inspection of the file that it only contains a few defaults and an instruction to include the etc xinetd d directory To enable or disable a xinetd service edit its configuration file in the etc xinetd d directory If the disable attribute is set to yes the service is disabled If the disable attribute is set to no the service is enabled If you edit any of the xinetd configuration files or change its enabled status using Serviceconf ntsysv or chkconfig you must restart xinetd with the command service xinetd restart before the changes Chapter 8 Controlling Access to Services 93 will take effect For a list of network services controlled by xinetd list of the contents of the etc xinetd d directory with the command 1s etc xinetd d 8 3 Serviceconf Serviceconf is a graphical application developed by Red Hat to configure which SysV ser vices in etc rc d init d are started at boot time for runlevels 3 4 and 5 and which xinetd services are enabled It also allows you to start stop and restart SysV services as well as restart xinetd To start Servicec
192. in paste and the appropriate package will be verified e Do you want to find out more information about a particular program You can try the following command to locate the documentation which came with the package that owns that program rpm qdf usr bin md5sum The output would be like the following usr share doc textutils 2 0a NEWS usr share doc textutils 2 0a README usr info textutils info gz usr man manl cat 1 gz asr man manl cksum 1 gz usr man man usr man man usr man man asr man man asr man man usr man man asr man man usr man man usr man man usr man man asr man man usr man man usr man man asr man man usr man man usr man man asr man man comm 1 gz csplit 1 gz cut 1 gz expand 1 gz ftmt 1 gz fold l gz head 1 gz join 1 gz mda5sum 1 gz nl 1 gz od 1 gz paste 1l gz pr 1 gz ptx 1 gz sort 1 gz split 1 gz sum 1 gz 226 Chapter 25 Package Management with RPM usr man manl tac 1 gz usr man manl tail 1l gz usr man manl tr 1 gz usr man manl tsort 1 gz usr man manl unexpand 1 gz usr man manl uniq 1 gz usr man manl we 1 gz e You may find a new RPM but you do not know what it does To find information about it use the following command rpm qip sndconfig 0 48 1 1386 rpm The output would look like the following Name sndconfig Relocations not relocateable Version 0 48 Vendor Red Hat Release 3 Build Date Mon 10 Jul 2000 02 25 40 Install date
193. indow If there are any problems discovered during the verify process they will be described in the main display area 26 5 3 Uninstalling Packages Uninstalling a package removes the application and associated files from your machine When a package is uninstalled any files it uses that are not needed by other packages on your system are also removed Configuration files that have been modified are copied to lt filename gt rpmsave so you can reuse them later ote You must be root to uninstall packages If uninstalling a package would break dependencies which could interfere with the oper ation of applications that require one or more of the removed files in the package a dialog will pop up asking you to confirm the deletion You can uninstall a selected package in a variety of ways from the menu under Packages from the toolbar and from the Query function If you decide to remove more than one pack age at a time you can choose more than one package in the same way as you would when installing querying or verifying The total number of selections will be displayed in the sta tus bar on the bottom of the main window Remove the following packages vim common 6 0 0 21 vim minimal 6 0 0 21 Figure 26 11 Uninstall Window Chapter 26 Gnome RPM 241 Once you have begun to uninstall packages Gnome RPM asks for confirmation showing a window like the one in Figure 26 11 All of the packages that are about to be uninsta
194. ing checkbox 7 Click Next 8 If your ISP is in the pre configured list select it Otherwise enter the required infor mation about your ISP account If you do not know the values contact your ISP Click Next 9 On the Create Dialup Connection page click Finish After configuring the modem device it appears in the device list as shown in Figure 6 6 78 Chapter 6 Network Configuration Devices Hardware Hosts ONS You may configure network devices associated 4 with physical hardware here Multiple logical devices can be associated with a single piece of hardware Status Device Nickname Type Add Edit Copy Delete Activate Deactivate Monitor aun varply x chose Figure 6 6 Modem Device Be sure to click Apply to save the changes After adding the modem device you can edit its configuration by selecting the device from the device list and clicking Edit For example when the device is added it is configured not to start at boot time by default Edit its configuration to modify this setting Compression PPP options login name password and more can also be changed When the device is added it is not activated as seen by its Inactive status To activate the device select it from the device list and click the Activate button 6 5 Establishing an xDSL Connection DSL stands for Digital Subscriber Lines There are different types of DSL such as
195. irrored copy on each disk Mirroring remains popular due to its simplic ity and high level of data availability Level 1 operates with two or more disks that may use parallel access for high data transfer rates when reading but more commonly oper ate independently to provide high I O transaction rates Level 1 provides very good data reliability and improves performance for read intensive applications but at a relatively 1 A hot swap chassis allows you to remove a hard drive without having to power down your system Chapter 4 Redundant Array of Independent Disks RAID 65 2 RAID level 1 comes at a high cost because you write the same information to all of the disks in high cost The storage capacity of the level 1 array is equal to the capacity of one of the mirrored hard disks in a Hardware RAID or one of the mirrored partitions in a Software RAID Level 4 Level 4 uses parity concentrated on a single disk drive to protect data It is bet ter suited to transaction I O rather than large file transfers Because the dedicated parity disk represents an inherent bottleneck level 4 is seldom used without accompanying tech nologies such as write back caching Although RAID level 4 is an option in some RAID partitioning schemes it is not an option allowed in Red Hat Linux RAID installations The storage capacity of Hardware RAID level 4 is equal to the capacity of member disks minus the capacity of one member disk The storage capaci
196. is recommended that you use Red Hat Network or the Red Hat Linux errata page available at http www redhat com apps support errata Packages from Red Hat have been verified for integrity and are GPG signed by Red Hat so that you can make sure they are the official packages 26 1 Starting Gnome RPM To start Gnome RPM use one of the following methods On the GNOME desktop go to Main Menu Button on the panel gt Programs gt System gt GnoRPM e On the KDE desktop go to Main Menu Button on the panel gt System gt GnoRPM e Type gnorpmat a shell prompt You will see the main Gnome RPM window as shown in Figure 26 1 rote If you would like to install upgrade or uninstall packages you must be root The easiest way to become root is to type the su command and Enter at a shell prompt Then type the root password However you do not have to be root to query and verify packages The Gnome RPM interface consists of the following Package Display on the left allows you to browse and select packages on your system e Display window to the right of the package panel shows you contents from folders in the panel e Toolbar above the display and panel a graphical display of package tools e Menu above the toolbar contains text based commands as well as help info prefer ences and other settings e Status bar beneath the panel and display windows shows the total number of selected packages C
197. ize of a system s video card 01 00 0 VGA compatible controller Matrox Graphics Inc MGA G400 AGP rev 04 prog if 00 VGA Subsystem Matrox Graphics Inc Millennium G400 Dual Head Max Flags medium devsel IRQ 16 Memory at 4000000 32 bit prefetchable size 32M Memory at fcffc000 32 bit non prefetchable size 16K Memory at fc000000 32 bit non prefetchable size 8M Expansion ROM at 80000000 disabled size 64K Capabilities dc Power Management version 2 Capabilities f0 AGP version 2 0 20 5 Additional Resources To learn more about gathering system information refer to the following resources 20 5 1 Installed Documentation e ps help The ps help displays a list of options that can be used with ps top manual page Type man top to learn more about top and its many options e free manual page type man free to learn more about free and its many options Chapter 20 Gathering System Information 177 e df manual page Type man df to learn more about the df command and its many op tions e du manual page Type man du to learn more about the du command and its many op tions e proc The contents of the proc directory can also be used to gather more detailed system information Refer to the Official Red Hat Linux Reference Guide for additional infor mation about the proc directory 178 Chapter 20 Gathering System Information 3 redhat Chapter 21 Printer Configurati
198. k for debugging purposes The User value corresponds to the User directive It sets the userid used by the server to answer requests This user s settings determine the server s access Any files inaccessible to this user will also be inaccessible to your website s visitors The default for User is apache The user should only have privileges so that it can access files which are supposed to be visible to the outside world The user is also the owner of any CGI processes spawned by the server The user should not be allowed to execute any code which is not intended to be in response to HTTP requests warning Unless you know exactly what you are doing do not set the user directive to root Using root as the User will create large security holes for your Web server The parent httpd process first runs as root during normal operations but is then immedi ately handed off to the apache user The server must start as root because it needs to bind to a port below 1024 Ports below 1024 are reserved for system use so they can not be used by anyone but root Once the server has attached itself to its port however it hands the process off to the apache user before it accepts any connection requests 134 Chapter 13 Apache Configuration The Group value corresponds to the Group directive The Group directive is similar to the User directive Group sets the group under which the server will answer requests The de fault group is also apache
199. key would have been displayed as the standard output on the monitor screen Now the file mykey asc can be inserted into email or exported to a keyserver To see the key type less mykey asc to open the file in a pager type q to quit the pager It should look like the following Version GnuPG v1 0 1 GNU Linux Comment For info see http www gnupg org mQGiBDkHP 3URBACkWGsYh4 3pkXU9wj X1G67K8 DSr185r7dNtHNf LL ewill0k2 q8saWJn2 6QZP sSDVqdUJMOdH J6kQOTAt INzObgcVrxLYNfgeBsvkHF POtnYcZRgL tZ6syBBWs8JB4xt5V09iTJSGAMPUQE8Jpdn2aRXPApdoDwl179LM8Rq6rt gwCg5ZZa pGN1lkgFu24WM5wC1zg4QTbMD 3MJCSxf L99Ek5HXcB3yhj o0LmIrGAVBgoWdrRd BIGJQOFhV1INSwC8YhN 4nGHWpaTxgEtnb4CI1lwI G3DK901LYMyRJinkGJ6XYf P3b cCQmgATDF 5ugIAmdditnw7deXqn eavaMxRXJM ROSgJJyVpbA020qKe6L6Inb5H kjcZA 9obTm4 99dDMRO CNR92 fA5prO0zriy ziLUow cq 15 9nt bEbInY1m MUN6 SWO jJCH pIQH5lerV EookyOyq3o0cUdjeRYF d2j19xmeSyL2H3tDvnuE6vgqFU N sdvby4B21ku7S h0 6W6GPQAe pzdyX9vS Pnf80su7W3 j 60WprOQkUGF 1bCBHYWxs YWdoZXIgPHBhdWxnYWxsQHJ1ZGhhdC5 jb20 i FYEEXECABYFA jkHP 3UECWOEAWMV AwIDFgIBAheAAAOJEJECmvGCP SWpMjQAONF 2zVvRgdR 80r9pBhu95zeSnkb7AKCm uXVS0a5KON7J61 1VvEwx1 1poLkBDQQ5Bz MEAQA8 zt cCWRJ jW8cHCgLaE402jyqQ 37gDT n4VS66nU YIt z lt DFScVmgMuFRzhibLb1f09TpZzxEbSF 3T 6p 9hLLnHCQ1bD HRsKf h0eJYMMgqB3 HyUpNeqCMEEd9AnWD 9P 4rQtO7Pes38sV01X00SvsTyMG9IWEB vSNZk R1 phA55r1s8cAAWUEAJjqazvk0bgFrwlOPG9m7 fEeD1VPSV6HSA0 fvz4w c7ckfpuxg URON 3TJA00Acprk8Gg8J2CtebAyR sP5IsrK5111luGdk 10M85FpT
200. kickstart file the network is enabled If you would like to include a post installation script type it in the text area Do not include the spost command It will be added for you For example to change the message of the day for the newly installed system add the fol lowing command to the spost section echo Hackers will be punished gt etc motd 2 11 1 Chroot Environment If you want your post installation script to run outside of the chroot environment click the checkbutton next to this option on the top of the Post Installation window This is equivalent to the using the nochroot option in the post section rip If you want to make any changes to the newly installed filesystem in the post installation section outside of the chroot environment you must append the directory name with mnt sysimage For example if you check the Run outside of the chroot environment button the previous example needs to be changed to the following 56 Chapter 2 Kickstart Configurator echo Hackers will be punished gt mnt sysimage etc motd 2 11 2 Use an Interpreter If you want to specify a scripting language to use to execute your script click the Use an interpreter button and enter the interpreter in the text box beside the button For example usr bin per 1 can be specified for a Perl script This option corresponds to using spost interpreter usr bin per1 in your kickstart file 2 11 3 Examples The post insta
201. ks on the communications between your machine and the remote ma chine The openssh package includes core files needed by both the OpenSSH client programs and the OpenSSH server The openssh package also contains scp a secure replacement for rcp for copying files between machines and ftp for transferring files between machines The openssh askpass package supports the display of a dialog window which prompts for a password during use of the OpenSSH agent with RSA authentication The openssh askpass gnome package contains a GNOME GUI desktop environment dialog window which is displayed when OpenSSH programs prompt for a password If you are running GNOME and using OpenSSH utilities you should install this package The openssh server package contains the sshd secure shell daemon and related files The secure shell daemon is the server side of the OpenSSH suite and must be installed on your host if you want to allow SSH clients to connect to your host The openssh clients package contains the client programs needed to make encrypted connections to SSH servers including the following ssh a secure replacement for rsh and slogin a secure replacement for rlogin for remote login and telnet for com municating with another host via the TELNET protocol For more information about OpenSSH see Chapter 9 and the OpenSSH website at http www openssh com openssl devel The openss1 devel package contains the static libraries and the i
202. l key server key to make sure that the permissions are set correctly on your key After you use the above commands to create your key you will not need to use a password to start your secure Web server Efon Disabling the password feature for your secure Web server is a security risk We DO NOT recommend that you disable the password feature for your secure Web server The problems associated with not using a password are directly related to the security main tained on the host machine For example if an unscrupulous individual compromises the regular UNIX security on the host machine that person could obtain your private key the contents of your server key file The key could be used to serve Web pages that will appear to be from your Web server If UNIX security practices are rigorously maintained on the host computer all operating system patches and updates are installed as soon as they are available no unnecessary or risky services are operating and so on the secure Web server s password may seem unnec essary However since your secure Web server should not need to be re booted very often the extra security provided by entering a password is a worthwhile effort in most cases The server key file should be owned by the root user on your system and should not be accessible to any other user Make a backup copy of this file and keep the backup copy in a safe secure place You need the backup copy because if you ever lose t
203. le in which public and secret keys are kept Then when you download a document or file from that entity you can check the validity of that document against the key you added to your keyring To import a key use the import option To demonstrate download and import Red Hat s public key That way any time you want to validate a package from Red Hat you will be able to check it against the key you retrieved You can find Red Hat s key at http www redhat com about contact html Using your browser download the key by pressing the Shift key while you click on the download link then click the OK button to save the file for example redhat 2 asc Then at the shell prompt import the key with the following command gpg import redhat2 asc The resulting message tells you that the key was processed To check that the key was added type gpg list keys You will see the key you just downloaded from Red Hat as well as your own keys newuser localhost newuser gpg list keys home newuser gnupg pubring gpg pub 1024D DB42A60E 1999 09 23 Red Hat Inc lt security redhat com gt sub 2048g 961630A2 1999 09 23 rip Sometimes you will not be able to download a key from a link Keys are text files so they can be moved to your machine in any way a regular text file can be saved As long as you know the name and location of the file you saved you can import it to your keyring 25 3 2 Verifying Packages To check the GnuPG sign
204. lect Force to be a primary partition if you want the partition to be a primary partition Select Check for bad blocks if you want the installation program to check for bad blocks on the hard drive before formatting it Continue these steps to create as many partitions as needed for your RAID setup Notice that all the partitions do not have to be RAID partitions For example you can configure only the nome partition as a software RAID device Once you have all of your partitions created as software RAID partitions select the Make RAID button on the Disk Druid main partitioning screen see Figure 5 3 Next Figure 5 2 will appear where you can make a RAID device Filesystem type ext3 m RAID Level RAIDO m RAID Members Number of spares po r Format partition OK Cancel Figure 5 2 Making a RAID Device e First enter a mount point e Next choose the filesystem type for the partition e Choose your RAID level You can choose from RAID 0 RAID 1 and RAID 5 ote If you are making a RAID partition of boot you must choose RAID level 1 and it must use one of the first two drives IDE first SCSI second If you are not creating a RAID partition of boot and you are making a RAID partition of it must be RAID level 1 and it must use one of the first two drives IDE first SCSI second Chapter 5 Software RAID Configuration e Select which partitions will go into this RAID array and click OK e A spa
205. llation program they will already appear in the hardware list on the Hardware tab 5 If you selected Other Ethernet Card the Select Ethernet Adapter window appears Select the manufacturer and model of the Ethernet card and the device If this is the first Ethernet card for the system select ethO if this is the second Ethernet card for the system select eth1 and so on The Network Administration Tool also allows the user to configure the resources for the wireless network interface card Click Next to continue 6 On the Configure Wireless Connection page as shown in Figure 6 12 configure the ESSID mode frequency channel transmit rate and key for your wireless device Configure Wireless Connection ESSID Network ID Mode Frequency Channel Transmit Rate Key lt Back X Cancel Figure 6 12 Wireless Settings 7 On the Configure Network Settings page choose between DHCP and static IP ad dress You may specify a hostname for the device If the device receives a dynamic IP address each time the network is started do not specify a hostname Click Next to continue 8 Click Finish on the Create Wireless Device page Chapter 6 Network Configuration 83 After configuring the wireless device it appears in the device list as shown in Figure 6 13 Devices Hardware Hosts DNS ey You may configure network devices associated 3 with physical hardware
206. llation script can be used to perform any useful functions such as the following examples Turn services on and off sbin chkconfig level 345 telnet off sbin chkconfig level 345 finger off sbin chkconfig level 345 lpd off sbin chkconfig level 345 httpd on Run a script named runme from an NFS share mkdir mnt temp mount 10 10 0 2 usr new machines mnt temp open s w mnt temp runme umount mnt temp Add a user to the system usr sbin useradd bob usr bin chfn f Bob Smith bob usr sbin usermod p kjdf 04930FTH bob 2 12 Saving the File After you have finished choosing your kickstart options click the Save File button A dialog box similar to Figure 2 15 will appear to allow you to review your choices before saving the file Chapter 2 Kickstart Configurator You have choosen the following configuration Click Save File to save the kickstart file Click Cancel to return to the program Generated by Kickstart Configurator System language lang en_US Language modules to install langsupport default en_US en_US fr_FR en_US System keyboard keyboard us System mouse H Probe for Mouse System timezone timezone utc America New_York H Root password 7 rootpw iscrypted 1 CANxOyBasOZOIKKSBJLH 4RC2 VIT3x90 Figure 2 15 Confirm Options zj 57 If you are happy with your choices click the Save File button within the dialog box A save file dialog box will appear
207. lled are listed You should carefully check the list to make sure that you are not about to remove something you want to keep Clicking the Yes button will start the uninstallation process After it is completed the packages and groups that have been removed will disappear from any open windows 26 5 3 1 Upgrading Packages When a new version of a package is released it is easy to install it on your system Select the package from the window of available packages in the same way you select packages for installation You can begin the upgrade process in two ways either the Upgrade button on the toolbar or using Operations gt Upgrade on the menu You simply Add packages in the same manner as you would during a new package installation During the upgrade you will see a progress indicator like the one shown when you are installing packages When it is finished any old versions of the packages will be removed unless you specify otherwise refer to Section 26 4 for more information In most cases you should upgrade packages rather than uninstall the old versions of a pack age and then install the new ones If you use upgrade any changes you made to package configuration files are preserved properly If you uninstall an old version of a package and then install a new package your changes could be lost If you run out of disk space during an installation the install will fail However the package which was being installed when the error o
208. llowing locations e The official Red Hat Linux CD ROMs The Red Hat Errata Page available at http www redhat com apps support errata e A Red Hat FTP Mirror Site available at http www redhat com download mirror html e Red Hat Network See Chapter 27 for more details on Red Hat Network 25 2 2 Installing RPM packages typically have file names like foo 1 0 1 1386 rpm The file name includes the package name foo version 1 0 release 1 and architecture i386 Installing a pack age is as simple as logging in as root and typing the following command at a shell prompt rpm ivh foo 1 0 1 i386 rpm foo FEE AE aE a a a aE aE AE a aE aE HE EH EH EEEE Chapter 25 Package Management with RPM 219 As you can see RPM prints out the name of the package and then prints a succession of hash marks as the package is installed as a progress meter ote Although a command like rpm ivh foo 1 0 1 i386 rpm is commonly used to install an RPM pack age you may want to consider using rpm Uvh foo 1 0 1 i386 rpm instead The u option is com monly used for upgrading a package but it will also install new packages See Section 25 2 4 for more information about using the u RPM option Installing packages is designed to be simple but you may sometimes see errors 25 2 2 1 Package Already Installed If the package of the same version is already installed you will see rpm ivh foo 1 0 1 i386 rpm foo package foo 1 0 1 is alr
209. location If the path for your RPMs does not match the default path in your preferences you will be presented with a window for browsing through your filesystem which will allow you to select the correct path for your new RPMs Under Package Colours you will find color coding for packages The default setting for older packages is gray for current packages the color is green for newer packages than those installed the color is blue These color values can be customized to suit your needs The RPM Directories field contains a list of default locations where Gnome RPM will search for packages when the Install window is first opened For example mnt cdrom RedHat RPMS is listed by default If you have the Red Hat Linux CD mounted in this location Gnome RPM will search it for RPM packages when you open the Install window In the Network tab you have the ability to specify proxies for use with HTTP and FTP transfers as well as user and password names see Figure 26 6 Note however that the password will not be stored securely In the Cache expire field you can set the length of time before data from the rpmfind database is considered to be out of date Behaviour Package Listing Install Window Network Rpmfind Distributions Network Settings HTTP Proxy FTP Proxy Proxy User Proxy Password Cache expire 14 days Local Hostname tictactoe meridian redhat com Bok y Apply X Close 2 Help
210. log box Click OK The Pass to CGI Scripts section configures the PassEnv directive If you want to remove an environment variable so that the value is not passed to CGI scripts and SSI pages use the Unset for CGI Scripts section Click Add in the Unset for CGI Scripts section and enter the name of the environment variable to unset This corresponds to the UnsetEnv directive 13 2 4 Directories Use the Directories page to configure options for specific directories This corresponds to the lt Directory gt directive 126 Chapter 13 Apache Configuration Site Configuration Logging Environment Variables Directories Default Directory Options Edit ExecCGl FollowSymLinks Includes IncludesNOEXEC Indexes SymLinkslfOwnerMatch 0K X Cancel Help Figure 13 6 Directories Click the Edit button in the top right hand corner to configure the Default Directory Op tions for all directories that are not specified in the Directory list below it The options that you choose are listed as the Options directive within the lt Directory gt directive You can configure the following options ExecCGI Allow execution of CGI scripts CGI scripts are not executed if this option is not chosen FollowSymLinks Allow symbolic links to be followed Includes Allow server side includes IncludesNOEXEC Allow server side includes but disable the exec and include commands in CGI scripts Indexes Display a
211. lt LHS gt lt RHS gt would be used Looking up users and groups by number is handled by making 501 uid a CNAME for jim passwd and 501 gid a CNAME for jim group Note that the LHS and RHS do not have periods put in front of them when the library determines the name for which to search so the LHS and RHS usually begin with periods Chapter 1 Kickstart Installations 21 enablesmbauth Enables authentication of users against an SMB server typically a Samba or Windows server SMB authentication support does not know about home directories UIDs or shells So if you enable it you will need to make users accounts known to the workstation by enabling LDAP NIS or Hesiod or by using the usr sbin useradd command to make their accounts known to the workstation To use this option you must have the pam_smb package installed smbservers The name of the server s to use for SMB authentication To specify more than one server separate the names with commas smbworkgroup The name of the workgroup for the SMB servers enablecache Enables the nscd service The nscd service caches information about users groups and various other types of information Caching is especially helpful if you choose to distribute information about users and groups over your network using NIS LDAP or hesiod 1 4 3 boot loader boot loader required Specifies how the boot loader should be installed and whether the boot load
212. m package that contains support for up to 64 gigabyte of memory Again it is rec ommended that you also install the kernel package for debugging purposes The kernel bigmem package is only built for the i686 architecture If you are uprgrading the kernel on a laptop or are using PCMCIA the kernel pcemcia cs package is also required You do not need the kernel source package unless you plan to recompile the kernel your self or plan to perform kernel development The kerne1 doc package contains kernel de velopment documentation and is not required The kernel util package includes utilities that can be used to control the kernel or the system s hardware and is not required Red Hat builts kernels that are optimized for different x86 versions The options are athlon for AMD Athlon and AMD Duron systems i686 for Intel Pentium II Intel Pen tium III and Intel Pentium 4 systems and i586 for Intel Pentium and AMD K6 systems If you do not know the version of your x86 system use the kernel built for the i386 version it is built for all x86 based systems The x86 version of the RPM package is included in the file name For example kernel 2 4 18 0 12 athlon rpmis optimized for AMD Athlon and AMD Duron systems and kernel 2 4 18 0 12 1686 rpmis optimized for Intel Pentium II Intel Pentium IIL and Intel Pentium 4 systems When you have determined which packages you need to upgrade your kernel select th
213. make a mistake press the Reset button on the page to clear your pasted key Fite Edit Settings Help en BEGIN PGP PUBLIC KEY BLOCK Version GnuPG v1 0 1 GNU Linux Comment For info see http www gnupg org mOGi BDkHPSURBACKWGsYh43pkXUSw j X1G67K8 DSr 1 85r7dNtHNFLL ewi 110k2 q8sallIn2602PsD qdUJMOdHF JEKOTAtSNzObgcVrxLYNfgeBsvkHF POtnYcZRgL tZbsyBBls8IJB4xt5VO9i ISGAMPUQES Ipdn2aRXPApdoDw17SLMBRqbr qulgSZZa pGN1 kgFu24uNSuCizg4OTbMD SMICSxPFLOSEkSHXcB3yh j o0LmIrGAYBgolldrRd BIG JQOFHVINSwCSYhN 4nGHilpaTxgEtnb4CI1wI G3DK901 YMyRJ inkGJ6XYFP3b cCOmgATDF Sug Amddi tnw deXqn eavalxRXIM ROSgIJy pbANZ0qKe6L6 InbSH kjoZA SobTm499dDNRO CNRIZFASprOzr iy ziLUow ceg 59nt bEbIny LmFmUNG SWOjCH pIOQHS lerV EookyOyq3ocld jeRYF d2 j 1 SxmeSyL2H3tDvnuE6vgqFU N sdvby4B2Iku7S hOBWEGPOAe pzdyX9v5 Pnf8osu7W3 j60WprOkUGFIbCBHYlxs bldoZX I gPHBhdllxnblxsQHJ1ZGhhdC5 jb20 iF YEExECABYFAjKHP3UECwoEAuMY Aw DFgI BAheAARO JE JECmyGCPShipM jOAoNF2zvRodR 8or SpBhu9SzeSnkb7AKCm uXV SOa5KoN J61 1vEwx1 1 poLk BDOQOSBz MEAQASztcliRJ jlW8cHCgLaE402 jyqQ 37 QDT n4VS66nU tzDFSc mghuFRzhibLb1 FO9TpZzxEbSF3TEpShLLnHCOLbD HRskfhOeJ YMMQB3 HyUpNeqCMEEdSAnwWDSP4rOt07Pes38sV01 XO0Svs TYNGIWEB VSNZk R1 phASSris8cAAWWEA jgazvkObgFrwLOPG9m7FEeD vPSYEHSA0Fyzdus cfckfpuxg URONF3T JAQOAcprk8Gg8J2CtebAYR sP5Isrk5111luGdk 0M85F pT fcen20dJt ToAF 6fGnIkeCeP1O5 ali TbDgdAUHBRykpdllU3GI7NSE923FVg5khOig uwrAiEYEGBECAAYFAjKHP4uACgkOkOK
214. make sure that you have the proper RPM packages installed The openssh server package is required and depends on the openssh package Both of these packages are included in Red Hat Linux 7 3 The OpenSSH daemon uses the configuration file etc ssh sshd_config The default con figuration file installed with Red Hat Linux 7 3 should be sufficient for most purposes If you want to configure the daemon in ways not provided by the default sshd_config read the sshd man page for a list of the keywords that can be defined in the configuration file To start the OpenSSH service use the command sbin service sshd start To stop the OpenSSH server use the command sbin service sshd stop If you want the daemon to start automatically at boot time see Chapter 8 for information on how to manage services 9 3 Configuring an OpenSSH Client To connect to an OpenSSH server from a client machine you must have the openssh clients and openssh packages installed on the client machine 9 3 1 Using the ssh Command The ssh command is a secure replacement for the rlogin rsh and telnet commands It allows you to log in to and execute commands on a remote machine Logging in to a remote machine with ssh is similar to using telnet To log in to a remote machine named penguin example net type the following command at a shell prompt 98 Chapter 9 OpenSSH ssh penguin example net The first time you ssh to a remote machine you will see a message similar to t
215. mat This option is useful for applications where you want to increase the number of inodes on the filesystem type lt xX gt replaced by fstype This option is no longer available Use fstype fstype Sets the filesystem type for the partition Valid values are ext 2 ext 3 swap and vfat 32 Chapter 1 Kickstart Installations start Specifies the starting cylinder for the partition It requires that a drive be specified with ondisk or ondrive It also requires that the ending cylinder be specified with end or the partition size be specified with size end Specifies the ending cylinder for the partition It requires that the starting cylinder be specified with start badblocks Specifies that the partition should be checked for bad sectors All partitions created will be formatted as part of the installation process unless noformat and onpart are used ote If partitioning fails for any reason diagnostic messages will appear on virtual console 3 1 4 20 raid raid optional Assembles a software RAID device This command is of the form raid lt mntpoint gt level lt level gt device lt mddevice gt lt partitions gt The lt mntpoint gt is the location where the RAID filesystem is mounted If it is the RAID level must be 1 unless a boot partition boot is present If a boot partition is present the boot partition must be level 1 and the root partition can be any of the avail
216. mb service is started by typing the command service smb restart at a shell prompt 6 If you want the smb service to start automatically use nt sysv chkconfig or service conf to enable it at runtime Refer to Chapter 8 for details rip To learn more about encrypted passwords read usr share doc samba lt version gt docs htmldocs ENCRYPTION html replace lt version gt with the version number of Samba that you have installed The pam_smbpass PAM module can be used to sync users Samba passwords with their sys tem passwords when the passwd command is used If a user invokes the passwd command Chapter 11 Samba 109 the password he uses to log in to the Red Hat Linux system as well as the password he must provide to connect to a Samba share are changed To enable this feature add the following line to etc pam d system auth below the pam_cracklib so invocation password required lib security pam_smbpass so nullok use_authtok try_first_pass 11 3 Connecting to a Samba Share To connect to a Linux Samba share from a Microsoft Windows machine use Network Neigh borhood or Windows Explorer To connect to a Samba share from a Linux system from a shell prompt type the following command smbclient hostname sharename U username You will need to replace host name with the hostname or IP address of the Samba server you want to connect to sharename with the name of the shared directory you want to browse and username wit
217. mbers 147 printconf See printer configuration printer configuration 179 cancel print job 193 command line options 192 creating an alias 191 CUPS printing system 193 configuration interface 195 default printer 190 delete existing printer 190 driver options 192 Assume Unknown Data is Text 192 Convert Text to Postscript 192 Effective Filter Locale 192 Page Size 192 Prerender Postscript 192 Send End of Transmission EOT 192 Send Form Feed FF 192 edit driver 191 edit existing printer 190 exporting settings 192 importing settings 192 local printer 181 LPRng 179 managing print jobs 193 modifying existing printers 190 Novell NetWare NCP printer 185 overriding a printer 190 printing from the command line 193 remote UNIX printer 182 rename existing printer 191 Samba SMB printer 184 save configuration to file 192 strict RFC1179 compliance 183 test page 190 text based application 179 viewing print spool 193 printtool See printer configuration processes 171 currently running 171 ps 171 R RAID 63 configuring software RAID 67 explanation of 63 Hardware RAID 63 level 0 64 level 1 64 level 4 64 level 5 64 levels 64 reasons to use 63 Software RAID 63 RAM 173 Red Hat Network 243 Red Hat Network Administration Tool 265 See network configuration Red Hat Package Manager See RPM redhat config network See network configuration redhat config users See
218. middle mouse button click From the Time Zone menu choose the time zone to use for the system Enter the desired root password for the system in the Root Password text entry box If you want to save the password as an encrypted password in the file select Encrypt root pass word When the file is saved the plaintext password that you typed will be encrypted and written to the kickstart file Do not type an already encrypted password and select to encrypt it Choose one or more languages to install and use after installation from the Language Sup port list Choosing Reboot system after installation will reboot your system automatically after the installation is finished Kickstart installations are performed in graphical mode by default To override this default and use text mode instead check the Perform installation in text mode button You can perform a kickstart installation in interactive mode This means that the installation program will use all the options pre configured in the kickstart file but it will allow you to preview the options in each screen before you can continue to the next screen To continue to the next screen click the Next button after you have approved the settings If you are not satisfied with the pre configured options you can change them before continuing the instal lation If you prefer this type of installation check the Perform installation in interactive mode button 2 2 Boot Loader Options File
219. mpt from within any X Window System desktop Then choose the Filesystems tab Eie View Settings Windows Help CIRA Processes all Memory Usage resident Filesystems free boot home Sum of Free E CPU 9 16 user 4 38 system 5 43pm up 2 days loadavg 0 14 0 17 0 26 Figure 20 3 GNOME System Monitor The du command displays the estimated amount of space being used by files in a directory If you type du at a shell prompt the disk usage for each of the subdirectories will be displayed in a list The grand total for the current directory and subdirectories will also be shown as Chapter 20 Gathering System Information 175 the last line in the list If you do not want to see all the subdirectories use the command du hs to see only the grand total for the directory in human readable format Use the du help command to see more options 20 3 1 Monitoring Filesystems Red Hat Linux provides a utility called diskcheck that monitors the amount of free disk space on the system Based on the configuration file it will send email to the system admin istrator when one or more disk drives reach a specified capacity This utility is run as an hourly cron task The following variables can be defined in etc diskcheck conf e defaultCutoff When disk drives reach this percent capacity it will be reported For example if defaultCutoff 90 an email will be sent when the monitored disk
220. n external URL and enter a complete URL including the http in the Location field Choose File to redirect the client to an internal URL and enter a file location under the document root for the Web server The location must begin the a slash and be relative to the Document Root For example to redirect a 404 Not Found error code to a Web page that you created in a file called 404 html copy 404 html to DocumentRoot errors 404 html In this case DocumentRoot is the Document Root directory that you have defined the default is var www htm1 Then choose File as the Behavior for 404 Not Found error code and enter errors 404 htm1 as the Location From the Default Error Page Footer menu you can choose one of the following options e Show footer with email address Display the default Apache footer at the bottom of all error pages along with the email address of the website maintainer specified by the Chapter 13 Apache Configuration 123 ServerAdmin directive Refer to Section 13 3 1 1 for information about configuring the ServerAdmin directive Show footer Display just the default Apache footer at the bottom of error pages No footer Do not display a footer at the bottom of error pages 13 2 2 Logging By default Apache writes the transfer log to the file var log httpd access_log and the error log to the file var log httpd error_log Site Configuration Transfer Log A Log to File fogsvaccess og tt Brow
221. n and Package Selection options will be disabled They are not supported for kickstart upgrades Also choose the type of kickstart installation to perform from this screen You can choose from the following options e CD ROM Choose this option if you wish to install Red Hat Linux from the Red Hat Linux CD ROMs e NFS Choose this option if you wish to install Red Hat Linux from an NFS shared di rectory Two text entry boxes for the NFS server and NFS directory will appear Enter 46 Chapter 2 Kickstart Configurator the fully qualified domain name or IP address of the NFS server For the NFS directory enter the name of the NFS directory that contains the RedHat directory For example if your NFS server contains the directory mirrors redhat i386 RedHat enter mir rors redhat i386 for the NFS directory FTP Choose this option if you wish to install Red Hat Linux from an FTP server Two text entry boxes for the FTP server and FTP directory will appear Enter the fully qualified domain name or IP address of the FTP server For the FTP directory enter the name of the FTP directory that contains the RedHat directory For example if your FTP server contains the directory mirrors redhat i386 RedHat enter mirrors redhat i386 for the FIP directory HTTP Choose this option if you wish to install Red Hat Linux from an HTTP server Two text entry boxes for the HTTP server and HTTP directory will appear Enter the fully qualifie
222. n arrow buttons beside the Hour Minute and Sec ond in the Time section Changes will not take place until you click the Apply button rote Changing the date and time will change the system clock as well as the hardware clock Clicking Apply or Ok is equivalent to executing the date and hwclock commands with the selected date and time The Network Time Protocol NTP daemon synchronizes the system clock with a remote time server or time source such as a satellite dateconfig allows you to configure a NTP daemon to synchronize your system clock with a remote server To enable this feature click the Enable Network Time Protocol button This will enable the Server pulldown menu You can choose one of the predefined servers or type a server name in the pulldown menu Your system will not start synchronizing with the NTP server until you click Apply After you click Apply the configuration will be saved and the NTP daemon will be started or restarted if it is already running If you want this daemon to start automatically at boot time you need to execute the command sbin chkconfig level 345 ntpd on to en able nt pd for runlevels 3 4 and 5 Chapter 18 Time and Date Configuration 165 For more information on NTP read the NTP documentation available in the usr share doc ntp version number directory Clicking the Apply button will apply any changes that you have made to the date and time the NTP daemon settings and the time zone se
223. n rmmod followed by the module name The rmmod utility will only unload modules that are not in use and that are not a dependency of other modules in use For example the command sbin rmmod tulip unloads the tulip network interface module Another useful kernel module utility is modinfo You can use the command sbin modinfo to display information about a kernel module The general syntax is sbin modinfo options lt module gt Options include a that displays a brief description of the module and p that lists the pa rameters the module supports For a complete list of options refer to the modinfo man page man modinfo 24 2 Additional Resources For more information on kernel modules and their utilities refer to the following resources 24 2 1 Installed Documentation e lsmod man page description and explanation of its output e insmod man page description and list of command line options Chapter 24 Kernel Modules 213 modprobe man page description and list of command line options rmmod man page description and list of command line options modinfo man page description and list of command line options usr src linux 2 4 Documentation kmod txt description of kmod and why it re placed kerneld e usr src linux 2 4 Documentation modules txt how to compile and use kernel modules 214 Chapter 24 Kernel Modules Package Management 3 redhat Chapter 25 Package Management
224. n service sendmail stop sbin service postfix start If you selected Sendmail you must make sure the post fix service is stopped and the send mail service is started sbin service postfix stop sbin service sendmail start rip For more information about email protocols and MTAs refer to the Official Red Hat Linux Reference Guide System Configuration redhat Chapter 17 Console Access When normal non root users log into a computer locally they are given two types of special permissions 1 They can run certain programs that they would not otherwise be able to run 2 They can access certain files normally special device files used to access diskettes CD ROMs and so on that they would not otherwise be able to access Since there are multiple consoles on a single computer and multiple users can be logged into the computer locally at the same time one of the users has to win the race to access the files The first user to log in at the console owns those files Once the first user logs out the next user who logs in will own the files In contrast every user who logs in at the console will be allowed to run programs that accom plish tasks normally restricted to the root user If X is running these actions can be included as menu items in a graphical user interface As shipped the console accessible programs include halt poweroff and reboot 17 1 Disabling Shutdown Via Ctrl Alt Del By default etc initt
225. nclude file needed to compile applications with support for various cryptographic algorithms and protocols You need to install this package only if you are developing applications which include SSL support you do not need this package to use SSL stunnel The stunnel package provides the Stunnel SSL wrapper Stunnel supports the SSL en cryption of TCP connections so it can provide encryption for non SSL aware daemons Chapter 14 Apache Secure Server Configuration 139 and protocols such as POP IMAP and LDAP without requiring any changes to the daemon s code Table 14 1 displays the location of the secure server packages and additional security related packages within the package groups provided by Red Hat Linux This table also tells you whether each package is optional or not for the installation of a secure Web server Table 14 1 Security Packages yes yes Applications Internet yes Applications Internet yes openssh askpass gnome Applications Internet yes yes yes yes yes 14 3 An Overview of Certificates and Security Your secure Web server provides security using a combination of the Secure Sockets Layer SSL protocol and in most cases a digital certificate from a Certificate Authority CA SSL handles the encrypted communications and the mutual authentication between browsers and your secure Web server The CA approved digital certificate provides authentication for your secure Web server the CA pu
226. nd Sometimes a command contains words that would be displayed in a different style on their own such as filenames In these cases they are considered to be part of the command so the entire phrase will be displayed as a command For example Use the cat test file command to view the contents of a file named test file in the current working directory filename Filenames directory names paths and RPM package names are represented this way This style should indicate that a particular file or directory exists by that name on your Red Hat Linux system Examples The bashrc file in your home directory contains bash shell definitions and aliases for your own use The etc fstab file contains information about different system devices and filesys tems Install the webalizer RPM if you want to use a Web server log file analysis program application This style should indicate to you that the program named is an end user application as opposed to system software For example Use Netscape Navigator to browse the Web key A key on the keyboard is shown in this style For example To use Tab completion type in a character and then press the Tab key Your terminal will display the list of files in the directory that start with that letter key combination A combination of keystrokes is represented in this way For example The Ctrl AIt Backspace key combination will exit your graphical session and return yo
227. nd sbin 1smod displays a list of currently loaded modules Example 24 1 Example 1smod output Module Size Used by sr_mod 15264 0 autoclean mga 95984 1 agpgart 23392 3 nfs 79008 1 autoclean lockd 52464 1 autoclean nfs 212 Chapter 24 Kernel Modules sunrpc 61328 1 autoclean nfs lockd autofs 11264 4 autoclean 3c59x 25344 1 autoclean ipchains 38976 0 unused ide scsi 8352 0 scsi_mod 95104 2 sr_mod ide scsi ide cd 26848 0 cdrom 27232 0 sr_mod ide cd usb uhci 20720 0 unused usbcore 49664 Lofusb hci As you can see in Example 24 1 1smod displays the size use count and referring modules for each module currently loaded To load a kernel module you can use the command sbin insmod followed by the kernel module name By default insmod tries to load the module from the lib modules lt kernel version gt kernel drivers subdirectories There is a subdirectory for each type of module such as the net subdirectory for network interface drivers Some kernel modules have module dependencies other modules must be loaded first for it to load To resolve these dependencies you can either load the module dependencies and then load the module you want or you can use the command sbin modprobe followed by the module name to load the module along with its dependencies For example the command sbin modprobe tulip loads the tulip network interface module To unload kernel modules use the command sbi
228. nd a base DN with 1dapserver and ldapbasedn enableldapauth Use LDAP as an authentication method This enables the pam_ldap module for au thentication and changing passwords using an LDAP directory To use this option you must have the nss_ldap package installed You must also specify a server and a base DN with ldapserver and ldapbasedn ldapserver If you specified either enableldap or enableldapauth the name of the LDAP server to use This option is set in the etc ldap conf file ldapbasedn If you specified either enableldap or enableldapauth the DN distinguished name in your LDAP directory tree under which user information is stored This option is set in the etc ldap conf file Chapter 1 Kickstart Installations enableldaptls Use TLS Transport Layer Security lookups This option allows LDAP to send en crypted usernames and passwords to an LDAP server before authentication enablekrb5 Use Kerberos 5 for authenticating users Kerberos itself does not know about home directories UIDs or shells So if you enable Kerberos you will need to make users accounts known to this workstation by enabling LDAP NIS or Hesiod or by using the usr sbin useradd command to make their accounts known to this worksta tion If you use this option you must have the pam_krb5 package installed krb5realm The Kerberos 5 realm to which your workstation belongs krb5kdc The KDC or KDCs th
229. nes over a secure encrypted connection It is similar to rcp The general syntax to transfer a local file to a remote system is scp localfile username tohostname newfilename The localfile specifies the source and the group of username t ohostname newfilename specifies the destination To transfer the local file shadowman to your account on penguin example net type the fol lowing at a shell prompt replace username with your username scp shadowman username penguin example net home username This will transfer the local file shadowman to home username shadowman on penguin example net The general syntax to transfer a remote file to the local system is scp username tohostname remotefile newlocalfile The remotefile specifies the source and newloca1 file specifies the destination Multiple files can be specified as the source files For example to transfer the contents of the directory downloads to an existing directory called uploads on the remote machine penguin example net type the following at a shell prompt scp downloads username penguin example net uploads Chapter 9 OpenSSH 99 9 3 3 Using the sftp Command The sftp utility can be used to open a secure interactive FTP session It is similar to ftp except that it uses a secure encrypted connection The general syntax is sftp username hostname com Once authenticated you can use a set of commands similar to using FTP Refer to the sftp man page for a list of th
230. nf file for the DHCP server shipped with Red Hat Linux filename usr new machine kickstart next server blarg redhat com Note that you should replace the value after filename with the name of the kickstart file or the directory in which the kickstart file resides and the value after next server with the NFS server name If the filename returned by the BOOTP DHCP server ends with a slash then it is in terpreted as a path only In this case the client system mounts that path using NFS and searches for a particular file The filename the client searches for is 40 Chapter 1 Kickstart Installations lt ip addr gt kickstart The lt ip addr gt section of the filename should be replaced with the client s IP address in dotted decimal notation For example the filename for a computer with an IP address of 10 10 0 1 would be 10 10 0 1 kickstart Note that if you do not specify a server name then the client system will attempt to use the server that answered the BOOTP DHCP request as its NFS server If you do not specify a path or filename the client system will try to mount kickstart from the BOOTP DHCP server and will try to find the kickstart file using the same lt ip addr gt kickstart filename as described above 1 6 Starting a Kickstart Installation To begin a kickstart installation you must boot the system from a Red Hat Linux boot diskette or the CD ROM and enter a special boot command at the boot prompt If t
231. nf ssl key server key containing your key and a file named etc httpd conf ssl crt server crt containing your certificate If your key and certificate are somewhere else move them to these directories If you changed any of the default locations or filenames for the secure Web server in your Apache con figuration files you should put these two files in the appropriate directory based on your modifications Once these CA files have been moved restart your server with the command sbin service httpd restart If your key file is encrypted you will be asked for the password Type in your password to start your server Point your Web browser to your server s home page The URL to access your secure Web server will look like this https your_domain ote Note the s after http The https prefix is used for secure HTTP transactions If you are using a CA signed certificate from a well known CA your browser will probably automatically accept the certificate without prompting you for input and create the secure connection Your browser will not automatically recognize a test or a self signed certificate because the certificate is not signed by a CA If you are not using a certificate from a CA follow the instructions provided by your browser to accept the certificate You can just accept the defaults by clicking Next until the dialogs are finished Once your browser accepts the certificate your secure Web server will show you a
232. nfigured to start or stop using three different applications serviceconf a graphical application that displays a description of each service displays whether each service is started at boot time for runlevels 3 4 and 5 and allows you to start stop and restart each service ntsysv a text based application that allows you to configure which services are started at boot time for each runlevel Changes do not take effect immediately Services can not be started stopped or restarted using this program chkconfig a command line utility that allows you to turn services on and off for the different runlevels Changes do not take effect immediately Services can not be started stopped or restarted using this utility You may find that these tools are easier to use than the alternatives editing the numerous symbolic links located in the directories below etc rc d by hand or editing the xinetd configuration files in etc xinetd d Another way to manage access to system services is by using iptables to configure an IP firewall If you are a new Linux user please realize that iptables may not be the best solution for you Setting up iptables can be complicated and is best tackled by experienced UNIX Linux system administrators On the other hand the benefit of using iptables is flexibility For example if you need a customized solution which provides certain hosts access to certain services iptables can provide it for you S
233. ng it from scratch The Red Hat Linux installation program also creates a sample kick start file based on the options that you selected during installation It is written to the file root anaconda ks cfg You should be able to edit it with any text editor or word proces sor that can save files as ASCII text First be aware of the following issues when you are creating your kickstart file Items must be specified in order That order is e Command section Refer to Section 1 4 for a list of kickstart options You must include the required options e The packages section Refer to Section 1 4 29 for details e The spre and post sections These two sections can be in any order and are not required Refer to Section 1 4 30 and Section 1 4 31 for details e Items that are not required can be omitted e Omitting any required item will result in the installation program prompting the user for an answer to the related item just as the user would be prompted during a typical installation Once the answer is given the installation will continue unattended unless it finds another missing item e Lines starting with a pound sign are treated as comments and are ignored For kickstart upgrades the following items are required e Language Installation method e Device specification if device is needed to perform installation e Keyboard setup e The upgrade keyword e LILO configuration If any other items are specif
234. ng the firewall 90 basic firewall configuration 88 configuring common services 89 DHCP 89 ipchains service 90 local hosts 88 mail relay 90 gnome lokkit 87 See Also GNOME Lokkit Gnome RPM 229 configuration 234 installing packages 232 package display 231 package manipulation 238 querying packages 238 removing packages with 240 selecting packages 231 starting 230 uninstalling packages with 240 upgrading packages with 241 verifying packages 239 Gnu Privacy Guard 223 Red Hat key 224 using 253 GnuPG See Gnu Privacy Guard GPG See Gnu Privacy Guard group configuration adding groups 169 filtering list of groups 167 modify groups for a user 168 modify users in groups 170 modifying properties 170 viewing list of groups 167 groups See group configuration floppy use of 162 H hardware viewing 175 Hardware Browser 175 Hardware RAID See RAID hwbrowser 175 information about your system 171 initrd 249 insmod 212 installation kickstart See kickstart installations secure server 137 Internet connection See network configuration introduction ix ISDN connection See network configuration K kernel building 247 252 custom 247 252 downloading 207 initrd image for 249 large memory support 206 modular 247 module loader kmod 211 modules 211 monolithic 252 multiple processor support 206 upgrading 205 kernel modules listing 211 loading 212 unload 212
235. nistrator with the sender Disk Usage Monitor e mailProg Specify the mail program to use to sent email alerts For example if mailProg usr sbin sendmail is specified Sendmail will be used as the mail program You do not have to restart a service if you change the configuration file because it is read each time the cron task is run 20 4 Hardware If you are having trouble configuring your hardware or just want to know what hardware is in your system you can use the Hardware Browser application to display the hardware that can be probed To start the program type hwbrowser at a shell prompt As shown in Figure 20 4 it displays your CD ROM devices floppy disks hard drives and their partitions 1 Refer to Chapter 22 for more information on cron 176 Chapter 20 Gathering System Information network devices pointing devices system devices and video cards Click on the category name in the left menu and the information will be displayed Selected Device CD ROM Drives Floppy Disks Hard Drives Network devices Pointing devices System devices Device Information Manufacturer Matrox Driver Card Matrox Millennium G200 N A Device Figure 20 4 Hardware Browser You can also use the 1spci command to list all PCI devices Use the command 1spci v for more verbose information or lspci vv for very verbose output For example 1spci can be used to determine the manufacturer model and memory s
236. none Build Host porky devel redhat com Group Applications Multimedia Source RPM sndconfig 0 48 1 srce rpm Size gt 461734 License GPL Packager Red Hat lt http bugzilla redhat com bugzilla gt Summary The Red Hat Linux sound configuration tool Description Sndconfig is a text based tool which sets up the configuration files you 1ll need to use a sound card with a Red Hat Linux system Sndconfig can be used to set the proper sound type for programs which use the dev dsp dev audio and dev mixer devices The sound settings are saved by the aumix and sysV runlevel scripts Perhaps you now want to see what files the sndconfig RPM installs You would enter the following rpm qlp sndconfig 0 48 1 i386 rpm The output will look like the following usr sbin pnpprobe usr sbin sndconfig usr share locale cs LC_MESSAGES sndconfig mo usr share locale da LC_MESSAGES sndconfig mo usr share locale de LC_MESSAGES sndconfig mo usr share locale es LC_MESSAGES sndconfig mo usr share locale fr LC_MESSAGES sndconfig mo usr share locale hu LC_MESSAGES sndconfig mo usr share locale id LC_MESSAGES sndconfig mo usr share locale is LC_MESSAGES sndconfig mo usr share locale it LC_MESSAGES sndconfig mo usr share locale ko LC_MESSAGES sndconfig mo usr share locale no LC_MESSAGES sndconfig mo usr share locale pt LC_MESSAGES sndconfig mo usr share locale pt_BR LC_MESSAGES sndconfig mo usr share locale ro LC_MESSAGES sndconfig mo
237. not filtered more than once first try selecting Raw Print Queue or Postscript Printer if you are configuring a remote printer After applying the changes print a test page to test this configuration If the test fails the remote print server might not have a print driver configured Try selecting a print driver according to the manufacturer and model of the remote printer applying the changes and printing a test page lt Remote Printer Driver Figure 21 15 Incorrect Print Driver Configuration 21 6 1 Confirming Printer Configuration The last step is to confirm your printer configuration Click Finish if this is the printer that you want to add Click Back to modify the printer configuration 190 Chapter 21 Printer Configuration Click the Apply button in the main window to save your changes to the etc printcap configuration file and restart the printer daemon 1pd After applying the changes print a test page to ensure the configuration is correct Refer to Section 21 7 for details If you need to print characters beyond the basic ASCII set including those used for languages such as Japanese you need to go to your driver options and select Prerender Postscript Refer to Section 21 8 for details You can also configure options such as paper size if you edit the print queue after adding it 21 7 Printing a Test Page After you have configured your printer you should print a test page to make sure the printer is functi
238. nsole Access shutdown of the system will continue if not an error message will be written to the system console instead For more information on shut down allow see the shut down man page 17 2 Disabling Console Program Access In order to disable access by users to console programs you should run this command as root rm f etc security console apps In environments where the console is otherwise secured BIOS and boot loader passwords are set Ctrl Alt Delete is disabled the power and reset switches are disabled and so forth you may not want to allow any user at the console to run poweroff halt and reboot which are accessible from the console by default To remove these abilities run the following commands as root rm f etc security console apps poweroff rm f etc security console apps halt rm f etc security console apps reboot 17 3 Disabling All Console Access The PAM pam_console so module manages console file permissions and authentication See the Official Red Hat Linux Reference Guide for more information on configuring PAM If you want to disable all console access including program and file access comment out all lines that refer to pam_console so inthe etc pam d directory As root the following script will do the trick cd etc pam d for i im p d sed pam_console so s lt i gt foo amp amp mv foo i done 17 4 Defining the Console The pam_console so module use
239. nue You can also choose to mount your filesystem read only instead of read write by choosing Read only If for some reason this process fails you can choose Skip and this step will be skipped and you will go directly toa command shell If you select Continue it will attempt to mount your filesystem under the directory mnt sysimage If it fails to mount a partition it will notify you If you select Read Only it will attempt to mount your filesystem under the directory mnt sysimage but in read only mode If you select Skip your filesystem will not be mounted Choose Skip if you think your filesystem is corrupted Once you have your system in rescue mode a prompt appears on VC virtual console 1 and VC 2 use the Ctrl Alt F1 key combination to access VC 1 and Ctrl AIt F2 to access VC 2 sh 2 05a If you selected Continue to mount your partitions automatically and they were mounted successfully you are in single user mode To mount a Linux partition manually inside rescue mode create a directory such as foo and type the following command 1 Tocreate an installation boot diskette insert a blank floppy disk and use the images boot img file on the Red Hat Linux CD ROM 1 with the command dd if boot img of dev fd0 Chapter 3 Rescue Mode 61 mount t ext3 dev hda5 foo In the above command foo is a directory that you have created and dev hda5 is the partition you want to mount If the partiti
240. o define what is done with those files Look in the last section of etc security console perms for lines similar to lt console gt 0660 lt floppy gt 0660 root floppy lt console gt 0600 lt sound gt 0640 root lt console gt 0600 lt cdrom gt 0600 root disk and add a line like lt console gt 0600 lt scanner gt 0600 root Then when you log in at the console you will be given ownership of the dev scanner device and the permissions will be 0600 readable and writable by you only When you log out the device will be owned by root and still have 0600 now readable and writable by root only permissions 17 6 Enabling Console Access for Other Applications If you wish to make other applications accessible to console users you will have to do a bit more work First of all console access only works for applications which reside in sbin or usr sbin so the application that you wish to run must be there After verifying that do the following steps 1 Create a link from the name of your application such as our sample foo program to the usr bin consolehelper application cd usr bin ln s consolehelper foo 2 Create the file etc security console apps foo touch etc security console apps foo 3 Create a PAM configuration file for the foo service in etc pam d An easy way to do this is to start with a copy of the halt service s PAM configuration file and then modify the file if you want to change the behavior
241. o manage your mount points by only mounting them dynamically when they are accessed Autofs consults the master map configuration file etc auto master to determine which mount points are defined It then starts an automount process with the appropriate parame ters for each mount point Each line in the master map defines a mount point and a separate map file that defines the filesystems to be mounted under this mount point For example the etc auto mnt file might define mount points in the mnt directory this relationship would be defined in the etc auto master file Each entry in auto master has three fields The first field is the mount point The second field is the location of the map file and the third field is optional The third field can contain information such as a timeout value For example to mount the directory project52 on the remote machine penguin host net at the mount point mnt myproject on your machine add the following line to auto master mnt etc auto mnt timeout 60 Add the following line to etc auto mnt myproject rw soft intr rsize 8192 wsize 8192 penguin host net project52 The first field in etc auto mnt is the name of the mnt subdirectory This directory is cre ated dynamically by automount It should not actually exist on the client machine The sec ond field contains mount options such as rw for read and write access The third field is the location of the NFS export including the hostname an
242. o move and rename your key and certificate files mv etc httpd conf httpsd key etc httpd conf ssl key server key Chapter 14 Apache Secure Server Configuration 141 mv etc httpd conf httpsd crt etc httpd conf ssl crt server crt Then start your secure Web server with the command sbin service httpd start For a secure server you will be prompted to enter your password After you type it in and press Enter the server will start You should not need to get a new certificate if you are upgrading from a previous version of the secure Web server 14 5 Types of Certificates If you installed your secure Web server using the Red Hat Linux installation program a random key and a test certificate are generated and put into the appropriate directories Before you begin using your secure server however you will need to generate your own key and obtain a certificate which correctly identifies your server You need a key and a certificate to operate your secure Web server which means that you can either generate a self signed certificate or purchase a CA signed certificate from a CA What are the differences between the two A CA signed certificate provides two important capabilities for your server e Browsers will usually automatically recognize the certificate and allow a secure connec tion to be made without prompting the user e When a CA issues a signed certificate they are guaranteeing the identity of the organiza tion
243. ogged in to your user account and not as root You will see an introductory screen with key options including one recommended option the default similar to the following gpg GnuPG 1 0 1 Copyright C 1999 Free Software Foundation Inc This program comes with ABSOLUTELY NO WARRANTY This is free software and you are welcome to redistribute it under certain conditions See the file COPYING for details Please select what kind of key you want 1 DSA and ElGamal default 2 DSA sign only 4 ElGamal sign and encrypt Your selection In fact most of the screens which require you to choose an option will list the default option within parentheses You can accept the default options simply by pressing Enter In the first screen you should accept the default option 1 DSA and ElGamal This option will allow you to create a digital signature and encrypt and decrypt with two types of technologies Type 1 and then press Enter Next choose the key size or how long the key should be Generally the longer the key the more resistant against attacks your messages will be The default size 1024 bits should be sufficiently strong for most users so press Enter The next option asks you to specify how long you want your key to be valid Usually the default 0 key does not expire is fine If you do choose an expiration date remember that anyone with whom you exchanged your public key will also have to be informe
244. ogram The results of the test will be displayed when it is finished If your system is open to mail relay it is highly recom mended that you configure Sendmail to prevent it 7 5 2 Activating the ipchains Service The firewall rules will only be active if the ipchains service is running To manual start the service use the command sbin service ipchains restart To ensure that it is started when the system is booted issue the command sbin chkconfig level 345 ipchains on You can also use Serviceconf to activate ipchains See Section 8 3 3 redhat Chapter 8 Controlling Access to Services Maintaining security on your Red Hat Linux system is extremely important One way to manage security on your system is to carefully manage access to system services Your sys tem may need to provide open access to particular services for example httpd if you are running a Web server However if you do not need to provide a service you should turn it off this will minimize your exposure to possible bug exploits There are several different methods for managing access to system services You must decide which method you would like to use based on the service your system s configuration and your level of Linux expertise The easiest way to deny access to a service is to simply turn it off Both the services man aged by xinetd which we will talk about more later in this section and the services in the etc rc d hierarchy can be co
245. old Your etc 1lilo conf should look similar to the following boot dev hda map boot map install boot boot b prompt timeout 50 message boot message linear default linux image boot vmlinuz 2 4 18 0 12 ju12001 label linux initrd initrd 2 4 18 0 12 jul2001 img read only root dev hda5 image boot vmlinuz 2 4 18 0 12 label linux old initrd initrd 2 4 18 0 12 img read only root dev hda5 To activate your changes run the command sbin lilo v If all goes well you will see output similar to the following LILO version 21 4 4 Copyright C 1992 1998 Werner Almesberger lba32 extensions Copyright C 1999 2000 John Coffman Reading boot sector from dev hda Merging with boot boot b Mapping message file boot message Boot image boot vmlinuz 2 4 18 0 12 Added linux 252 Appendix A Building a Custom Kernel Boot image boot vmlinuz 2 4 18 0 12 ju12001 Added linux old Writing boot sector Be sure the messages contains Writing boot sector The after linux means that the sec tion labeled 1inux is the default kernel that LILO will boot From now on when the system boots you will see linux and 1inux old as LILO boot op tions To boot the new kernel 1inux simply press Enter or wait for LILO to time out If you want to boot the old kernel 1inux old select 1inux old and press Enter You can begin testing your new kernel by rebooting your computer and watching the mes sages to ensure your hardware
246. omplish performance or redundancy goals not attainable with one large and expensive drive This array of drives will appear to the computer as a single logical storage unit or drive RAID is a method in which information is spread across several disks using techniques such as disk striping RAID Level 0 disk mirroring RAID level 1 and disk striping with parity RAID Level 5 to achieve redundancy lower latency and or increase bandwidth for reading or writing to disks and maximize the ability to recover from hard disk crashes The underlying concept of RAID is that data may be distributed across each drive in the array in a consistent manner To do this the data must first be broken into consistently sized chunks often 32K or 64K in size although different sizes can be used Each chunk is then written to a hard drive in RAID according to the RAID level used When the data is to be read the process is reversed giving the illusion that multiple drives are actually one large drive 4 2 Who Should Use RAID Anyone who needs to keep large quantities of data on hand such as an average system ad ministrator would benefit by using RAID technology Primary reasons to use RAID include Enhanced speed e Increased storage capacity using a single virtual disk e Lessening the impact of a disk failure 4 3 Hardware RAID versus Software RAID There are two possible RAID approaches Hardware RAID and Software RAID 4 3 1 Hardware RAID
247. on The printconf application allows users to configure a printer in Red Hat Linux It helps maintain the etc printcap configuration file print spool directories and print filters Starting with version 7 3 Red Hat Linux ships with two printing systems The printconf application configures the printing system called LPRng LPRng is also the default printing system This chapter focuses on using Printconf to configure LPRng For more information on the alternate printing system called CUPS refer to Section 21 11 To use printconf you must have root privileges To start printconf use one of the following methods On the GNOME desktop select Main Menu Button on the Panel gt Programs gt Sys tem gt Printer Configuration to start the graphical version e On the KDE desktop select Main Menu Button on the Panel gt System gt Printer Configuration to start the graphical version e Type the command printconf gui at a shell prompt for example in an XTerm or a GNOME terminal to start the graphical version e You can also run printconf as a text based application if you do not have the X Win dow System installed or you just prefer the text based interface To run it log in as root or use the command su to temporarily change to the root user and type the command usr sbin printconf tui from a shell prompt Fcc Do not edit the etc printcap file Each time the printer daemon 1pa is started or restarted a new
248. on is of type ext 2 replace ext 3 with ext2 If you do not know the names of your partitions use the following command to list them fdisk l If your filesystem is mounted and you want to make your system the root partition use the command chroot mnt sysimage This is useful if you need to run commands such as rpm that require your root partition to be mounted as To exit the chroot environment type exit and you will return to the prompt From the bash prompt you can run many useful commands including anaconda gzip mkfs ext2 ps badblocks head mknod python bash hwclock mkraid pythonl 5 cat ifconfig mkswap raidstart chattr init mlabel raidstop chmod insmod mmd rcp chroot less mmount rlogin clock in mmove rm collage loader modprobe rmmod cp ls mount route cpio lsattr mpartition rpm dd lsmod mrd rsh ddcprobe mattrib mread sed depmode mbadblocks mren sh df mcd mshowfat sync e2fsck mcopy mt tac fdisk mdel mtools tail fsck mdeltree mtype tar fsck ext2 mdir mv touch fsck ext3 mdu mzip traceroute ftp mformat open umount gnome pty helper minfo pico uncpio grep mkdir ping uniq gunzip mke2fs probe zcat 3 3 Booting Single User Mode You may be able to boot single user mode directly If your system boots but does not allow you to log in when it has completed booting try single user mode If you are using GRUB use the following steps to boot into single user mode 1 If you have a GRUB password configured type p and en
249. on port 12331 http your_domain 12331 148 Chapter 14 Apache Secure Server Configuration ote Some of the example URLs used in this manual may need to be changed depending upon whether you are accessing your secure Web server or your non secure Web server Please view all URLs in this manual as general examples and not as explicit instructions that will work under all circum stances 14 11 Additional Resources If you followed the steps outlined in this chapter but you experienced a problem the first thing you should do is check the Red Hat Errata section of the Red Hat website at http www redhat com apps support errata If you purchased an Official Red Hat product which included support you are entitled to technical support Be sure to visit the Red Hat Support website at http www redhat com support to register for support You may also want to subscribe to the redhat secure server mailing list You can subscribe to this mailing list at http www redhat com mailing lists You can also subscribe to the redhat secure server mailing list by emailing lt redhat secure server request redhat com gt and include the word subscribe without the quotation marks in the Subject line Refer to Section 13 7 for additional references about Apache 14 11 1 Installed Documentation e mod_ssl documentation Open a Web browser and go to the URL http localhost manual mod mod_ssl on the server that is running Apache 14
250. onf use one of the following commands e On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt Serviceconf e On the KDE desktop go to the Main Menu Button on the Panel gt Red Hat gt System gt Serviceconf e Type the command serviceconf at a shell prompt for example in an XTerm or a GNOME terminal File Actions Edit Runlevel Help o gt a gt el o Currently Running in Runlevel 3 Editing Runlevel 3 oO amanda E amandaidx el amd O amidxtape apmd O arpwatch MI atd f Run cron jobs that were left out due to downtime Figure 8 1 Serviceconf Serviceconf displays the current runlevel as well as which runlevel you are currently edit ing To edit a different runlevel select Edit Runlevel from the pulldown menu and select runlevel 3 4 or 5 Refer to Section 8 1 for a description of runlevels Serviceconf lists the services from etc rc d init das well as the services controlled by xinetd Click on a service to display a brief description of that service at the bottom of the window 94 Chapter 8 Controlling Access to Services To start stop or restart a service immediately select the service and choose the action from the Actions pulldown menu You can also select the service and click the start stop or restart button on the toolbar If you select an xinetd service such as telnet the Start Stop and Restart buttons will not be active If you
251. ong with the processes use the com mand ps aux This list is a static list in other words it is a snapshot of what is running when you invoked the command If you want a constantly updated list of running processes use top as described below You can use the ps command in combination with the grep command to see if a process is running For example to determine if Gnome RPM is running use the following command ps ax grep gnorpm The top command displays currently running processes and important information about them including their memory and CPU usage The list is both real time and interactive An example of top s output is provided as follows 6 14pm up 2 days 19 29 5 users load average 0 10 0 06 0 07 71 processes 68 sleeping 2 running 1 zombie 0 stopped CPU states 2 7 user 0 5 system 0 0 nice 96 6 idle Mem 256812K av 252016K used 4796K free 97228K shrd 43300K buff Swap 265032K av 1328K used 263704K free 86180K cached PID USER PRI NI SIZE RSS SHARE STAT CPU SMEM TIME COMMAND 15775 joe 5 0 11028 10M 3192 S KES AN 0 46 emacs 14429 root 15 0 63620 62M 3284 R Od 24 57 63 33 X 17372 joe 11 0 1056 1056 840 R 0 5 0 4 0 00 top 17356 joe 2 O 4104 4104 3244 S a Ne E 0 00 gnome terminal 14461 joe 1 0 3584 3584 2104 S O21 13 0 17 sawfish 1 root 0 0 544 544 476 S 0 0 0 2 0 06 init 2 root 0 0 0 0 0 SW 0 0 0 0 0 00 kflushd 3 root 1 0 0 0 0 SW 0 0 0 0 0 24 kupdate 4 root 0 0 0 0 0 SW 0 0 0 0 0 00 kpiod 5 root 0
252. oning properly To print a test page select the printer that you want to test from the printer list and select the appropriate test page from the Test pulldown menu If you change the print driver or modify the driver options you should print a test page to test the different configuration 21 8 Modifying Existing Printers To delete an existing printer select the printer and click the Delete button on the toolbar The printer will be removed from the printer list Click Apply to save the changes and restart the printer daemon To set the default printer select the printer from the printer list and click the Default button on the toolbar The default printer icon y beside the default printer appears in the first column of the printer list If you want to modify an imported printer s settings you cannot modify its settings directly You must override the printer You can only override an imported printer that has been imported using the alchemist libraries Imported printers have the nA symbol beside them in the first column of the printer list To override the printer select the printer and choose File gt Override Queue from the pulldown menu After overriding a printer the original imported printer will have the symbol beside it in the first column of the printer list After adding your printer s you can edit settings by selecting the printer from the printer list and clicking the Edit button The tabbed window shown in
253. or the clients or apply a group of parameters to a group of declarations Some parameters must start with the option keyword Options configure DHCP options whereas parameters configure values that are not optional or control how the DHCP server behaves 112 Chapter 12 Dynamic Host Configuration Protocol DHCP Oi If you change the configuration file the changes will not take effect until you restart the DHCP daemon with the command service dhcpd restart Parameters including options declared before a section enclosed in curly brackets are considered global parameters Global parameters apply to all the sections below it In Example 12 1 the routers subnet mask domain name domain name servers and time offset options are used for both the apex and raleigh host statements As shown in Example 12 1 you can declare a subnet You must include a subnet declaration for every subnet in your network If you do not the DHCP server will fail to start In this example there are global options for every DHCP client in the subnet and a range declared Clients are assigned an IP address within the range Example 12 1 Subnet Declaration subnet 192 168 1 0 netmask 255 255 255 0 option routers 192 168 1 254 option subnet mask 255 255 255 07 option domain name example com option domain name servers 1926168 214 13 option time offset 97 Eastern Standard Time range 192 168 1 10 192 168 1 100 All subnets tha
254. orie oa Eea E ERa EEE 90 8 Controlling Access to Services ornsekenne renga iiiad 91 o EEEE AAE E T ET ET E E ATE 91 8 2 K A EATE 8 153 T PS AA E N A E 92 8 9 Service Combs senah e a a a e Wace e R n 93 OAs TUS ED ARE AE E EE E NT 94 lo kota e Lero tl Tie P AEE IERE A E EE TA 95 8 6 Additional ReSOULCES 20 eessesseseseceseestseseseseacsececeaesescececeseacsceesenaeaceeeeeesaeeeees 95 9 POM SSA ses es ste cc nets aseeasies cia seven so ge tas SEteNs Da E a decades adnate T estat A 97 9 1 Why Use OpenSSH cccesccscesecsesssesessesseseessseeseesessssseseeseesssneseeseessaesneseaseanenees 97 9 2 Configuring an OpenSSH Server 97 9 3 Configuring an OpenSSH Client ccccccccesccseesesteseseesesseeseseessesesnsseeseeeaness 97 9 4 Additional Resources 000 za 102 10 Network File System NFS 10 1 Why Use NFS csceees 10 2 Mounting NFS Filesystems 10 3 Exporting NFS Filesystems 104 10 4 Additional Resources ccsccccsessesseseeseetessestesesseeseseeseesessesssseessaseeseseeseeneaees 106 VT SAT ADA PAE NE A TE E E E Seents 107 11 1 Why Use Samba 107 11 2 Configuring Samba 107 11 3 Connecting to a Samba Share 109 11 4 Additional Resources csccseeceees 110 12 Dynamic Host Configuration Protocol DHCP 111 12 1 Why Use DHCP cescseesessestesteseeseens 111 12 2 Configuring a DHCP Servev 111 12 3 Configuring
255. our printer con figuration will not be restored Each time the printer daemon is restarted it creates a new etc printcap file from the special printconf configuration file If you have configured a backup system for your configuration files you should use the following method to save your printer configuration If you added any custom settings in the etc printcap local file you should save it as part of your backup system also To save your printer configuration type this command as root usr sbin printconf tui Xexport gt settings xml Chapter 21 Printer Configuration 193 Your configuration is saved to the file sett ings xml If you save this file you can restore your printer settings This is useful if your printer config uration is deleted you reinstall Red Hat Linux and do not have your printer configuration file anymore or you want to use the same printer configuration on multiple systems To restore the configuration type this command as root usr sbin printconf tui Ximport lt settings xml If you already have a configuration file you have configured one or more printers on the system already and you try to import another configuration file the existing configuration file will be overwritten If you want to keep your existing configuration and add the config uration in the saved file you can merge the files with the following command as root usr sbin printconf tui Ximport merge lt settings xml You
256. ow System is running If it is running the program starts in graphical mode as shown in Figure 21 17 If X is not detected it starts in text mode The redhat printer switcher is a tool which enables users to easily switch between various Gl Printing System LPRng CUPS that they have YS installed Please choose your Printing System Available Printing System C LPRng CUPS Bow amp Cancel Figure 21 17 redhat switch printer If you selected CUPS you must make sure the 1pd service is stopped and the cups service is started sbin service lpd stop sbin service cups start If you selected LPRng you must make sure the cups service is stopped and the 1pd service is started sbin service cups stop sbin service lpd start Also use chkconfig ntsysv or serviceconf to configure your sytsem to start the cups ser vice automatically and disable the 1pd service Refer to Chapter 8 for details Chapter 21 Printer Configuration 195 21 11 2 CUPS Configuration Interface After starting the cups daemon open a Web browser and connect to the URL http localhost 631 as shown in Figure 21 18 File Edit View Tab Settings Go Bookmarks Tools Help lt Back gt O Gt siop 100 S amp htpocahost6317 gt g 3a Administration Classes Help Jobs Printers Software Do Administration Tasks Manage Printer Classes On Line Help Manage Jobs Manage Printers Download the Current CUPS Softwar
257. p If you are using fdisk to create a RAID partition remember that instead of creating a partition as type 83 which is Linux native you must create the partition as type fa Linux RAID Also for best performance partitions within a given RAID array should span identical cylinders on drives e Create a partition In Disk Druid choose New to create a new partition see Figure 5 1 4 Filesystem Type software RAID Allowable Drives Mount Paint Not Applicable gt Size MB Additional Size Options A Fixed size v Fill all space up to MB 3000 Fill to maximum allowable size Force to be a primary partition _j Check for bad blocks OK Cancel Figure 5 1 Creating a New RAID Partition e Choose software RAID from the Filesystem Type pull down menu e You will not be able to enter a mount point you will be able to do that once you have created your RAID device 68 Chapter 5 Software RAID Configuration For Allowable Drives select the drive on which RAID will be created If you have multi ple drives all drives will be selected here and you must deselect those drives which will not have the RAID array on them Enter the size that you want the partition to be Select Fill to maximum allowable size if you want the partition to grow to fill all available space on the hard disk If you make more than one partition growable the partitions will share the available free space on the disk Se
258. package It also modifies the boot loader configuration file to boot the new kernel if either GRUB or LILO is installed This chapter discusses the steps necessary to upgrade the kernel on an x86 system only warning Building your own custom kernel is not supported by the Red Hat Linux Installation Support Team For more information on building a custom kernel from the source code refer to Appendix A 23 1 The 2 4 Kernel Red Hat Linux ships with a custom 2 4 kernel which offers the following features e The directory for the kernel source is usr src linux 2 4 instead of usr src linux e Support for the ext3 filesystem e Multi processor SMP support Support for up to 64 gigabytes of physical RAM the kernel bigmem package in Red Hat Linux 7 3 is compiled to support 64 gigabytes of physical memory e USB support Preliminary support for IEEE 1394 also referred to as FireWire devices 23 2 Preparing to Upgrade Before you upgrade your kernel you must take a few precautionary steps The first step is to make sure you have a working boot diskette for your system in case a problem occurs If the boot loader is not configured properly to boot the new kernel you will not be able to boot your system unless you have a boot diskette To create a boot diskette for your system you need to determine which version of the kernel you are currently running Execute the following command uname r You must be root to cr
259. quest based on the public key The certificate request contains information about your server and the company hosting it 3 Send the certificate request along with documents proving your identity toa CA We cannot tell you which certificate authority to choose Your decision may be based on your past experiences or on the experiences of your friends or colleagues or purely on monetary factors 142 Chapter 14 Apache Secure Server Configuration To see a list of CAs click on the Security button on your Navigator toolbar or on the padlock icon at the bottom left of the screen then click on Signers to see a list of certifi cate signers from whom your browser will accept certificates You can also search the Web for CAs Once you have decided upon a CA you will need to follow the instruc tions they provide on how to obtain a certificate from them 4 When the CA is satisfied that you are indeed who you claim to be they will send you a digital certificate 5 Install this certificate on your Web server and begin handling secure transactions Whether you are getting a certificate from a CA or generating your own self signed certifi cate the first step is to generate a key See Section 14 6 for instructions on how to generate a key 14 6 Generating a Key First cd to the etc httpd con directory Remove the fake key and certificate that were generated during the installation with the following commands rm ssl key server key rm s
260. r look at each of these scenarios 3 1 1 Unable to Boot Linux This problem is often caused by the installation of another operating system after you have installed Red Hat Linux Some other operating systems assume that you have no other op erating systems on your computer and they overwrite the Master Boot Record MBR that originally contained the GRUB or LILO boot loader If the boot loader is overwritten in this manner you will not be able to boot Red Hat Linux unless you can get into rescue mode Another common problem occurs when using a partitioning tool to resize a partition or create a new partition from free space after installation and it changes the order of your partitions If the partition number of your partition changes the boot loader will not be able to find it to mount the partition To fix this problem boot in rescue mode and modify boot grub grub conf if you are using GRUB or etc lilo conf if you are using LILO 3 1 2 Hardware Software Problems This category includes a wide variety of different situations Two examples include failing hard drives and forgetting to run LILO after building a new kernel if you are using LILO as your boot loader If you are using GRUB you do not have to execute a command to reread the GRUB configuration file However if you specify an invalid root device or kernel in the GRUB configuration file you might not know until you reboot your computer 60 Chapter 3 Rescue Mode In the
261. r printer list will then consist of the printers you configured on the system as well as the printers you imported from the saved configuration file If the imported configuration file has a print queue with the same name as an existing print queue on the system the print queue from the imported file will override the existing printer After importing the configuration file with or without the merge command you must restart the printer daemon with the command sbin service lpd restart or by starting printconf and clicking Apply 21 10 Managing Your Print Jobs When you send a print job to the printer daemon such as printing text file from Emacs or printing an image from The GIMP the print job is added to the print spool queue The print spool queue is a list of print jobs that have been sent to the printer and information about each print request such as the status of the request the username of the person who sent the request the hostname of the system that sent the request the job number and more To view the list of print jobs in the print spool open a shell prompt and type the command 1pq The last few lines will look similar to the following Example 21 1 Example of 1pq output Rank Owner ID Class Job Files Size Time active user localhost 902 A 902 sample txt 2050 01 20 46 If you want to cancel a print job find the job number of the request with the command 1pq and then use the command lprm job number For example lprm 902 would
262. r virtual host add the additional virtual hosts 5 Configure the server settings under the Server tab 6 Configure the connections settings under the Performance Tuning tab 7 Copy all necessary files to the DocumentRoot and cgi bin directories and save your settings in the Apache Configuration Tool 13 1 Basic Settings Use the Main tab to configure the basic server settings 120 Chapter 13 Apache Configuration arn Virtual Hosts Server Performance Tuning rBasic Setup Server Name Webmaster email address root locaihost Available Addresses All available addre on port 60 Set addresses for Apache to listen for requests on Box amp Cancel Help Figure 13 1 Basic Settings Enter a fully qualified domain name that you have the right to use in the Server Name text area This option corresponds to the ServerName directive in httpd conf The ServerName directive sets the hostname of the Web server It is used when creating redirection URLs If you do not define a server name Apache attempts to resolve it from the IP address of the system The server name does not have to be the domain name resolved from the IP address of the server For example you might want to set the server name to www your_domain com when your server s real DNS name is actually foo your_domain com Enter the email address of the person who maintains the Web server in the Webmaster email address text area This option correspon
263. ractive prompts for your input during scripts or programs shown this way For ex ample Use the 1s command to display the contents of a directory ls Desktop axhome logs paulwesterberg gif Mail backupfiles mail reports The output returned in response to the command in this case the contents of the direc tory is shown in this style prompt A prompt which is a computer s way of signifying that it is ready for you to input something will be shown in this style Examples stephen maturin stephen leopard login user input Text that the user has to type either on the command line or into a text box on a GUI screen is displayed in this style In the following example text is displayed in this style To boot your system into the text based installation program you will need to type in the text command at the boot prompt Introduction xiii Additionally we use several different strategies to draw your attention to certain pieces of information In order of how critical the information is to your system these items will be marked as note tip important caution or a warning For example rote Remember that Linux is case sensitive In other words a rose is not a ROSE is not a rOsE Ori The directory usr share doc contains additional documentation for packages installed on your system Oimportant If you modify the DHCP configuration file the changes will not take effect until you restart the
264. re modified The access control files are read each time a user tries to add or delete a cron task The root user can always use cron regardless of the user names listed in the access control files If the file cron allow exists only users listed in it are allowed to use cron and the at deny file is ignored If cron allow does not exist all users listed in cron deny are not allowed to use cron 22 1 3 Starting and Stopping the Service To start the cron service use the command sbin service crond start To stop the ser vice use the command sbin service crond stop It is recommended that you start the service at boot time Refer to Chapter 8 for details on starting the cron service automatically at boot time 22 2 Anacron Anacron is a task scheduler similar to cron except that it does not require the system to run continuously It can be used to run the daily weekly and monthly jobs usually run by cron To use the Anacron service you must have the anacron RPM package installed and the anacron service must be running To determine if the package is installed use the rpm q anacron command To determine if the service is running use the command sbin service anacron status 22 2 1 Configuring Anacron Tasks Anacron tasks are listed in the configuration file etc anacrontab Each line in the config uration file corresponds to a task and has the format period delay job identifier command period frequency in da
265. re partition can be specified for RAID 1 and RAID 5 If a software RAID partition fails the spare will automatically be used as a replacement For each spare you want to specify you must create an additional software RAID partition in addition to the parti tions for the RAID device In the previous step select the partitions for the RAID device and the partition s for the spare s Select the number of spares e Select whether you want the partition formatted e The RAID device will appear in the Drive Summary list as shown in Figure 5 3 At this point you can continue with your installation process Refer to the Official Red Hat Linux Installation Guide for further instructions Red Hat Linux Online Help Partitions Choose where you would like Red Hat Linux to be installed Ifyou do not know how to partition your system please read the section on partitioning in the Red Hat Linux Installation Guide Ifyou used automatic partitioning you can either accept the current partition settings click Next or modify the setup using Disk Druid the manual partitioning tool Ifyou just finished partitioning with fdisk you must define mount points for your partitions Use the Edit button once you have chosen a partition to define its mount point Ifyou are manually partitioning your system using Disk Druid you will see your current hard drive s and partitions displayed Hide Help Release Notes T Disk
266. re usually phrases instead of just a word The public key is written to ssh id_dsa pub The private key is written to ssh id_dsa It is important never to give anyone the private key 1 The stands for the home directory of the currently logged in user See the Official Red Hat Linux Getting Started Guide for more details 100 Chapter 9 OpenSSH 2 Change the permissions of your ssh directory using the command chmod 755 ssh 3 Copy the contents of ssh id_dsa pub to ssh authorized_keys on the ma chine to which you want to connect If the file ssh authorized_keys does not exist you can copy the file ssh id_dsa pub to the file ssh authorized_keys on the other machine 4 If you are running GNOME skip to Section 9 3 4 4 If you are not running the X Win dow System skip to Section 9 3 4 5 9 3 4 2 Generating an RSA Key Pair for Version 2 Use the following steps to generate a RSA key pair for version 2 of the SSH protocol This is the default starting with OpenSSH 2 9 1 To generate a RSA key pair to work with version 2 of the protocol type the following command at a shell prompt ssh keygen t rsa Accept the default file location of ssh id_rsa Enter a passphrase different from your account password and confirm it by entering it again The public key is written to ssh id_rsa pub The private key is written to ssh id_rsa Never distribute your private key to anyone 2 Change the permi
267. rmine which components to include in your new kernel If you are running the X Window System the recommended method is to use the command make xconfig Components are listed in different levels of menus and are selected using a mouse You can select Y yes N no or M module After choos ing your components click the Save and Exit button to create the configuration file usr src linux 2 4 config and exit the Linux Kernel Configuration program If you want to use the settings of a default Red Hat Linux kernel copy the the configuration file from the usr src linux 2 4 configs directory to usr src linux 2 4 config Then run the make xconfig command and only make the desired changes Be sure to save your changes to the configuration file Other available methods for kernel configuration are listed below e make config An interactive text program Components are presented in a linear format and you answer them one at a time This method does not require the X Win dow System and does not allow you to change your answers to previous questions e make menuconfig A text mode menu driven program Components are pre sented in a menu of categories you select the desired components in the same man ner used in the text mode Red Hat Linux installation program Toggle the tag corre sponding to the item you want included built in exclude lt M gt module or lt gt module capable This method does not require the X
268. ropriate section on adding a printer for a description of the options 21 8 3 Driver The Driver tab shows which print driver is currently being used This is the same list that you used when adding the printer If you change the print driver click OK to return to the main window Click Apply to save the change and restart the printer daemon 192 Chapter 21 Printer Configuration 21 8 4 Driver Options The Driver Options tab displays advanced printer options Options vary for each print driver Common options include Send Form Feed FF should be selected if the last page of your print job is not ejected from the printer for example the form feed light flashes If this does not work try selecting Send End of Transmission EOT instead Some printers require both Send Form Feed FF and Send End of Transmission EOT to eject the last page Send End of Transmission EOT if sending a form feed does not work Refer to Send FF above Assume Unknown Data is Text should be selected if your print driver does not recognize some of the data sent to it Only select it if you are having problems printing If this option is selected the print driver will assume that any data that it can not recognize is text and try to print it as text If you select this option and Convert Text to Postscript the print driver will assume the unknown data is text and then convert it to PostScript Prerender Postscript should be selected if you are printing ch
269. roup for the user To specify a user ID for the user select Specify user ID manually If the option is not selected the next available user ID starting with number 500 will be assigned to the new user Red Hat Linux reserves user IDs above 500 for system users Click OK to create the user User Name Full Name EE Password LOO i Confirm Password y y Login Shell winmash o Create home directory Home Directory homes V Create a private group for the user Specify user ID manually up fso SY Pax X Cancel Figure 19 2 New User To configure more advanced user properties such as password expiration modify the user s properties after adding the user Refer to Section 19 2 for more information To add the user to more user groups click on the User tab select the user and click Proper ties In the User Properties window select the Groups tab Select the groups that you want the user to be a member of select the primary group for the user and click OK 19 2 Modifying User Properties To view the properties of an existing user click on the Users tab select the user from the user list and click Properties from the button menu or choose Action gt Properties from the pull down menu A window similar to Figure 19 3 will appear Chapter 19 User and Group Configuration 169 i Account Info Password Info Groups User Name fmn sSCisS Full Name oesi S Password
270. roup of packages within a folder left click on one package Hold down the Shift key and left click on the final package you wish to select You will see that all of the packages between your starting and ending selections will be highlighted for selection The status bar at the bottom of Gnome RPM will display the total number of packages you have selected 26 3 Installing New Packages To install new packages choose Install from the toolbar In the Install window your view will depend upon what you have selected from the Filter pull down list on the top of the window Filter can be used to narrow your choices for viewing packages Available filters include the following e All packages All but installed packages e Only uninstalled packages e Only newer packages e Uninstalled or newer packages Chapter 26 Gnome RPM 233 Filter Uninstalled or newer packages _4 Package Info GE S Packages emacs 20 7 31 Sy Applications Sy Editors SEL ae TETE All The libraries needed to run the GNU Emacs Add m xemacs el 21 1 14 4 xemacs info 21 1 14 4 9 Collapse Tree EZ Query A Install Upgrade Cy check sig x Close Figure 26 3 The Install Window emacs X11 20 7 31 o gt emacs el 20 7 31 o Unselect text editor emacs leim 20 7 31 o All emacs nox 20 7 31 m xemacs 21 1 14 4 o Expand o Tree o Click on the Add button By default if your CD ROM is mounted with a R
271. roup will appear in the group list Group Name Specify group 1D manually GID 1500 Dok X cone Figure 19 4 New Group To add users to the group refer to Section 19 4 170 Chapter 19 User and Group Configuration 19 4 Modifying Group Properties To view the properties of an existing group select the group from the group list and click Properties from the button menu or choose Action gt Properties from the pull down menu A window similar to Figure 19 3 will appear Group Users Group Name devel PK X cone Figure 19 5 Group Properties The Group Users tab displays which users are members of the group Select additional users to add them to the group and unselect users to remove from the group Click OK or Apply to modify the users in the group j redhat Chapter 20 Gathering System Information Before you learn how to configure your system you should learn how to gather essential system information For example you should know how to find the amount of free memory the amount of available hard drive space how your hard drive is partitioned and what processes are running This chapter discusses how to retrieve this type of information from your Red Hat Linux system using simple commands and a few simple programs 20 1 System Processes The ps ax command displays a list of current system processes including processes owned by other users To display the owner of the processes al
272. row beside the printer name A list of drivers for your printer will appear Select one rip To learn more about the print drivers go to http Awww linuxprinting org printer_list cgi rip You can select a different print driver after adding a printer by starting printconf selecting the printer from the list clicking Edit clicking the Driver tab selecting a different print driver and applying the changes Chapter 21 Printer Configuration 189 Select a Print Driver Select a print driver for your printer Printer gt DeskJet 610C gt DeskJet 610CL V DeskJet 612C xP D DeskJet 630C D DeskJet 632C gt DeskJet 640C gt DeskJet 648C D DeskJet 660C sl lt q Back gt Next X amp Cancel Figure 21 13 Selecting a Print Driver As shown in Figure 21 14 the print driver processes the data that you want to print into a format the printer can understand Since a local printer is attached directly to your computer you need to select a print driver to process the data that is sent to the printer 6 Local Printer Driver Figure 21 14 Correct Print Driver Configuration If you are configuring a remote printer LPD SMB or NCP the remote print server usually has its own print driver If you select an additional print driver on your local computer the data will be filtered more than once and the data will be converted to a format that the printer can not understand To make sure the data is
273. rting the daemon 12 2 4 DHCP Relay Agent The DHCP Relay Agent dhcrelay allows you to relay DHCP and BOOTP requests from a subnet with no DHCP server on it to one or more DHCP servers on other subnets When a DHCP client requests information the DHCP Relay Agent forwards the request to the list of DHCP servers specified when the DHCP Relay Agent is started When a DHCP server returns a reply the reply is broadcast or unicast on the network that sent the original request The DHCP Relay Agent listens for DHCP requests on all interfaces unless the i argument is used to specify one or more interfaces to listen to To start the DHCP Relay Agent use the dhcrelay command followed by the name of at least one DHCP server to which the requests should be relayed It can be started with the following options 116 Chapter 12 Dynamic Host Configuration Protocol DHCP Table 12 1 DHCP Relay Agent Options Argument Description o Names of the network interfaces to configure If no interface is specified all network interfaces will be configured eliminating non broadcast interfaces if it can Port on which dhcrelay should listen The DHCP Relay Agent transmits requests to the servers on this port and transmits responses to the clients on the port one greater than this port las Force dhcrelay to run in the foreground always lq sd Disable printing the network configuration of dhcrelay on startup 12 3 Configuring a DHCP Client
274. rub grub conf The default GRUB configuration file looks similar to the following NOTICE You have a boot partition This means that all kernel paths are relative to boot default 0 timeout 30 splashimage hd0 0 grub splash xpm gz title Red Hat Linux 2 4 18 0 12 root hd0 0 kernel vmlinuz 2 4 18 0 12 ro root dev hda3 initrd initrd 2 4 18 0 12 img If you created a separate boot partition the paths to the kernel and initrd image are relative to the boot partition To add your new kernel to GRUB copy the existing title section to a new one and modify it to boot your new kernel image and initrd image if you have any SCSI devices and have created an initrd image Be sure the title of the new section is different from the title of the section to boot the old kernel By default Red Hat Linux uses Red Hat Linux and the kernel version in parentheses to differentiate between different kernels for GRUB to boot In our example the new boot grub grub conf file would look like the following NOTICE You have a boot partition This means that all kernel paths are relative to boot default 0 timeout 30 splashimage hd0 0 grub splash xpm gz title Red Hat Linux 2 4 18 0 12 ju12001 root hd0 0 kernel vmlinuz 2 4 18 0 12 jul2001 ro root dev hda3 initrd initrd 2 4 18 0 12 jul2001 img title Red Hat Linux 2 4 18 0 12 root hd0 0 kernel vmlinuz 2 4 18 0 12 ro root dev hda3 initrd initrd 2 4 18 0 12 img
275. s When you install Red Hat Linux the hardware on your system is probed and you provide information about how the system will be typically used and which programs should be loaded Based on this probing and the information you provide the installation program decides which modules need to be loaded at boot time The installation program sets up the dynamic loading mechanism to work transparently If you build your own custom kernel you can make all of these decisions for yourself If you add new hardware after installation and the hardware requires a kernel module you need to set up the dynamic loading mechanism Kudzu usually detects new hardware You can also add the new driver by editing the module configuration file etc modules conf For example if your system included a model SMC EtherPower 10 PCI network adapter at the time of installation the module configuration file will contain the following line alias eth0 tulip After installation if you install a second identical network adapter to your system add the following line to etc modules conf alias ethl tulip See the Official Red Hat Linux Reference Guide for an alphabetical list of kernel modules and the hardware supported by the modules 24 1 Kernel Module Utilities You can also use a group of commands to list load or unload kernel modules These com mands are useful if you want to try different modules or see if a module has been loaded successfully The comma
276. s in the text area e File Name File name of the DNS database file in var named Name slave example com Masters List fi 2 3 4 File Name slave example com zone amp Cancel Figure 15 4 Adding a Slave Zone The configuration shown in Figure 15 4 creates the following entry in etc named conf zone Slave example com type slave file slave example com zone masters 13 2 3 43 b The configuration file var named slave example com zone is created by the named ser vice when it downloads the zone data from the master server s After configuring the slave zone click OK to return to the main window as shown in Fig ure 15 1 From the pulldown menu choose File gt Apply to write the etc named conf configuration file and have the daemon reload the configuration files D reana Chapter 16 Mail Transport Agent MTA Configuration A Mail Transport Agent MTA is essential for sending email from a Red Hat Linux system The Mail User Agent MUA such as Mozilla Mail Mutt Pine and Evolution is used to read and compose email When a user sends an email from an MUA the messages is handed off to the MTA which sends the message to a series of MTAs until it reaches its destination Even if a user does not plan to send email from the system some automated tasks or system programs might use the bin mail command to send email containing log messages to the root user of the local system Red Hat Linu
277. s gt Filter system users and groups from the pull down menu For more information on users and groups refer to the Official Red Hat Linux Reference Guide 19 1 Adding a New User To add a new user click the New User button A window as shown in Figure 19 2 will appear Type the username and full name for the new user in the appropriate fields Type the user s password in the Password and Confirm Password fields The password must be at least six characters 168 Chapter 19 User and Group Configuration rip The longer the user s password the more difficult it is for someone else to guess it and log in to the user s account without permission It is also recommended that the password not be based on a word and that the password be a combination of letters numbers and special characters Select a login shell If you are not sure which shell to select accept the default value of bin bash The default home directory is home username You can change the home di rectory that is created for the user or you can choose not to create the home directory by unselecting Create home directory Red Hat Linux uses a user private group UPG scheme The UPG scheme does not add or change anything in the standard UNIX way of handling groups it simply offers a new con vention Whenever you create a new user by default a unique group with the same name as the user is created If you do not want to create this group unselect Create a private g
278. s Distribution Settings atin mirror Red Hat Linux 7 SRPMS uj redhat 7 O up O ftp ftp redhat com pub redhat up Red Hat Linux 7 i386 redhat 7 0 i3 0 ftp ftp redhat com pub redhat rec Red Hat Linux 7 386 upda redhat 7 O up O fip ftp redhat com pub redhatup Name 6 1 Powertools Alpha Origin ftp ftp redhat com pub redhat powertools 6 1 alpha Sources Rating 0 Preferred Mirror Hrom com pub linux redhat powertools 6 1 alphaq Change Bok Apply X Close Help Figure 26 8 Distribution Settings in Preferences In Distribution Settings you can set the options for choosing the most appropriate pack age out of the selections Rpmfind returns as well as which mirror you would like to use The higher the rating you indicate for your selection as shown in Figure 26 8 the higher the priority it will receive a lower rating such as 1 will specify that packages not be recommended 26 5 Package Manipulation 26 5 1 Querying Packages The easiest way to query packages is to use the Query option from the menu at the top If you want to query more than one package make all your selections and then press the Query button on the menu You will see a window like the one shown in Figure 26 9 The more packages you have queried the more tabs you will find within the Query box each tab representing a Query window for a package Chapter 26 Gnome RPM 239 emacs emacs 20 7 30 Size 21699067 Install Date
279. s the etc security console perms file to determine the permissions for users at the system console The syntax of the file is very flexible you can edit the file so that these instructions no longer apply However the default file has a line that looks like this lt console gt tty 0 9 0 9 0 9 0 9 0 9 When users log in they are attached to some sort of named terminal either an X server with aname like 0 or mymachine example com 1 0 ora device like dev ttyS0 or dev pts 2 The default is to define that local virtual consoles and local X servers are considered local but if you want to consider the serial terminal next to you on port dev ttyS1 to also be local you can change that line to read lt console gt tty 0 9 0 9 0 9 0 9 0 9 dev ttyS1 Chapter 17 Console Access 161 17 5 Making Files Accessible From the Console In etc security console perms there is a section with lines like lt floppy gt dev fd 0 1 dev floppy lt sound gt dev dsp dev audio dev midi dev mixer dev sequencer dev sound lt cdrom gt dev cdrom dev cdwriter You can add your own lines to this section if necessary Make sure that any lines you add refer to the appropriate device For example you could add the following line lt scanner gt dev scanner Of course make sure that dev scanner is really your scanner and not say your hard drive That s the first step The second step is t
280. s the system more secure because users can not connect to the daemon via the Internet Other command line options that can be specified in etc sysconfig dhcpd include e p lt portnum gt Specify the udp port number on which dhcpd should listen The de fault is port 67 The DHCP server transmits responses to the DHCP clients at a port num ber one greater than the udp port specified For example if you accept the default of port 67 the server listens on port 67 for requests and responses to the client on port 68 If you specify a port here and use the DHCP relay agent you must specify the same port on which the DHCP relay agent should listen See Section 12 2 4 for details e f Run the daemon as a foreground process This is mostly used for debugging d Log the DCHP server daemon to the standard error descriptor This is mostly used for debugging If this is not specified the log is written to var log messages e cf filename Specify the location of the configuration file The default location is etc dhepd conf e 1f filename Specify the location of the lease database file If a lease database file already exists it is very important that the same file be used every time the DHCP server is started It is strongly recommended that this option only be used for debugging purposes on non production machines The default location is var 1ib dhcp dhcpd leases e q Do not print the entire copyright message when sta
281. se Directories wv Log to Program ee oe Use System Log _j Use custom logging facilities Custom Log String __ aa Error Log A Log to File logs error_log 4 Browse w Log to Program E w Use System Log S Log Level Error 5d Reverse DNS Lookup Reverse Lookup zi ok X amp Cancel Help Figure 13 4 Logging The transfer log contains a list of all attempts to access the Web server It records the IP address of the client that is attempting to connect the date and time of the attempt and the file on the Web server that it is trying to retrieve Enter the name of the path and file in which to store this information If the path and filename does not start with a slash the path is relative to the server root directory as configured This option corresponds to the TransferLog directive You can configure a custom log format by checking Use custom logging facilities and en tering a custom log string in the Custom Log String field This configures the LogFormat directive Refer to http httpd apache org docs mod mod_log_config html formats for details on the format of this directive The error log contains a list of any server errors that occur Enter the name of the path and file in which to store this information If the path and filename does not start with a slash the path is relative to the server root directory as configured This option corresponds to the ErrorLog directive 124 Chapter 13 Apache Conf
282. se Address Table 1 2 3 1 one example com 1 2 3 2 two example com ok X Cancel Figure 15 3 Adding a Reverse Master Zone The configuration shown in Figure 15 3 creates the following entry in etc named conf zone 3 2 1 in addr arpa type master file 3 2 1 in addr arpa zone Me It also creates the file var named 3 2 1 in addr arpa zone with the following informa tion STTL 86400 IN SOA root localhost 2 serial 28800 refresh 7200 retry 604800 expire 86400 ttk IN NS ns example com 1 IN PTR one example com 2 IN PTR two example com After configuring the Reverse Master Zone click OK to return to the main window as shown in Figure 15 1 From the pulldown menu choose File gt Apply to write the 154 Chapter 15 BIND Configuration etc named conf configuration file write all the individual zone files in the var named directory and have the daemon reload the configuration files 15 3 Adding a Slave Zone To add a slave zone also known as a secondary master click the Add button and select Slave Zone Enter the domain name for the slave zone in the Domain name text area Anew window will appear as shown in Figure 15 4 with the following options Name The domain name that was entered in the previous window e Masters List The name server from which the slave zone retrieves its data This value must be a valid IP address You can only enter numbers and dot
283. se situations you may be unable to boot Red Hat Linux If you can get into rescue mode you might be able to resolve the problem or at least get copies of your most important files 3 2 Booting Rescue Mode To boot your system in rescue mode boot from a Red Hat Linux boot disk or the Red Hat Linux CD ROM 1 and enter the following command at the installation boot prompt boot linux rescue You can get to the installation boot prompt in one of these ways By booting your system from an installation boot diskette made from the boot img image This method requires that the Red Hat Linux CD ROM 1 be inserted as the rescue image or that the rescue image be on the hard drive as an ISO image By booting your system from the Red Hat Linux CD ROM 1 By booting from a network disk made from the boot net img or PCMCIA boot disk made from pemcia img You can only do this if your network connection is working You will need to identify the network host and transfer type For an explanation of how to specify this information refer to the Official Red Hat Linux Installation Guide After booting off a boot disk or Red Hat Linux CD ROM 1 and providing a valid rescue image you will see the following message The rescue environment will now attempt to find your Red Hat Linux installation and mount it under the directory mnt sysimage You can then make any changes required to your system If you want to proceed with this step choose Conti
284. ser types dos at the LILO prompt append lt params gt Specifies kernel parameters linear Use the linear LILO option this is only for backwards compatibility and linear is now used by default nolinear Use the nolinear LILO option linear is now used by default 28 Chapter 1 Kickstart Installations location Specifies where the LILO boot record is written Valid values are the following mbr the default or partition installs the boot loader on the first sector of the partition containing the kernel If no location is specified LILO is not installed lba32 Forces the use of lba32 mode instead of autodetecting 1 4 16 lilocheck lilocheck optional If 1ilocheck is present the installation program checks for LILO on the MBR of the first hard drive and reboots the system if it is found in this case no installation is performed This can prevent kickstart from reinstalling an already installed system 1 4 17 mouse mouse required Configures the mouse for the system both in GUI and text modes Options are device lt dev gt Device the mouse is on such as device ttyS0 emulthree If present simultaneous clicks on the left and right mouse buttons will be recog nized as the middle mouse button by the X Window System This option should be used if you have a two button mouse After options the mouse type may be specified as one of the following alpsps 2 ascii asciips 2 atibm
285. shell script to build an initrd image for your machine To use this command the loopback block device must be available To build the new initrd image run sbin mkinitrd with parameters such as this sbin mkinitrd boot initrd 2 4 18 0 12 jul2001 img 2 4 18 0 12 jul2001 In the above example boot initrd 2 4 18 0 12 ju12001 img is the file name of the new initrd image 2 4 18 0 12 ju12001 is the kernel whose modules from 1ib modules should be used in the initrd image This is not necessarily the same as the version number of the currently running kernel A 3 Configuring the Boot Loader Now that you have recompiled your kernel you must configure the boot loader to boot the new kernel This is a crucial step If you do not perform this step or if you perform it incorrectly you will not be able to boot your system If this happens boot your system with the boot diskette you created earlier and try configuring the boot loader again If your boot diskette does not work refer to Chapter 3 for more information about rescue mode In order to provide a redundant boot source to protect from a possible error in a new ker nel you should keep the original kernel available During the installation of Red Hat Linux 7 3 you had the option to choose either GRUB or LILO as your boot loader Refer to the appropriate section that follows 250 Appendix A Building a Custom Kernel A 3 1 GRUB If you selected GRUB as your boot loader modify boot g
286. sl crt server crt Next you need to create your own random key Type in the following command make genkey Your system will display a message similar to the following umask 77 usr bin openssl genrsa des3 1024 gt etc httpd conf ssl key server key Generating RSA private key 1024 bit long modulus EFRON ETEC ETE CLEES EEEE onda aay Carte gh ETSE EPERE cd ta Bad EEE eae aye iar dit sare 5 re We Le e is 65537 0x10001 Enter PEM pass phrase You now need to type in a password For best security your password should contain at least eight characters include numbers and or punctuation and not be a word in a dictionary Also remember that your password is case sensitive ote You will need to remember and enter this password every time you start your secure Web server so do not forget it You will be asked to re type the password to verify that it is correct Once you have typed it in correctly a file called server key containing your key will be created Note that if you do not want to type in a password every time you start your secure Web server you will need to use the following two commands instead of make genkey to create the key Both of these commands should be typed in entirely on one line Use the following command Chapter 14 Apache Secure Server Configuration 143 usr bin openssl genrsa 1024 gt etc httpd conf ssl key server key to create your key Then use this command chmod go rwx etc httpd conf ss
287. ssions of your ssh directory using the command chmod 755 ssh 3 Copy the contents of ssh id_rsa pub to ssh authorized_keys on the ma chine to which you want to connect If the file ssh authorized_keys does not exist you can copy the file ssh id_rsa pub to the file ssh authorized_keys on the other machine 4 If you are running GNOME skip to Section 9 3 4 4 If you are not running the X Win dow System skip to Section 9 3 4 5 9 3 4 3 Generating an RSA Key Pair for Version 1 3 and 1 5 Use the following steps to generate an RSA key pair which is used by version 1 of the SSH Protocol If you are only connecting between Red Hat Linux 7 3 systems you do not need an RSA version 1 3 or RSA version 1 5 key pair 1 To generate an RSA for version 1 3 and 1 5 protocol key pair type the following command at a shell prompt ssh keygen t rsal 1 The stands for the home directory of the currently logged in user See the Official Red Hat Linux Getting Started Guide for more details 1 The stands for the home directory of the currently logged in user See the Official Red Hat Linux Getting Started Guide for more details 1 The stands for the home directory of the currently logged in user See the Official Red Hat Linux Getting Started Guide for more details Chapter 9 OpenSSH 101 Accept the default file location ssh ident ity Enter a passphrase different from your account password Confirm the passp
288. st directive This email address is used in the footer of error pages if you choose to show a footer with an email address on the error pages In the Host Information section choose Default Virtual Host IP based Virtual Host or Name based Virtual Host 13 3 1 1 1 Default Virtual Host If you choose Default Virtual Host Figure 13 9 appears You should only configure one default virtual host The default virtual host settings are used when the requested IP address is not explicitly listed in another virtual host If there is no default virtual host defined the main server settings are used Chapter 13 Apache Configuration 129 j Basic Setup Site Configuration Virtual Host Name Virtual Hosto En Document Root Directory varw Browse ee vanables Webmaster email address rHost Information Default Virtual Host s X All requests on port es C Handle all remaining unhandled requests Figure 13 9 Default Virtual Hosts 13 3 1 1 2 IP based Virtual Host If you choose IP based Virtual Host Figure 13 10 appears to configure the lt VirtualHost gt directive based on the IP address of the server Specify this IP address in the IP address field To specify more than one IP address separate each IP address with spaces To specify a port use the syntax IP Address Port Use to configure all ports for the IP address Specify the host name for the virtual host in the Server Host Name fiel
289. st of the world For example examine the following lines mnt export speedy redhat com rw mnt export speedy redhat com rw The first line grants users from speedy redhat com read write access and denies all other users The second line grants users from speedy redhat com read only access the default and allows the rest of the world read write access Refer to the Official Red Hat Linux Reference Guide for a list of options that can be specified in the etc exports file Each time you change etc exports you must tell the NFS daemons to examine it for new information or reload the configuration file sbin service nfs reload 10 3 1 Starting and Stopping the Server On the server that is exporting NFS filesystems the nfs service must be running View the status of the NFS daemon with the command sbin service nfs status Start the NFS daemon with the command sbin service nfs start Stop the NFS daemon with the command sbin service nfs stop To start the nfs service at boot time use the command 106 Chapter 10 Network File System NFS sbin chkconfig level 345 nfs on You can also use ntsysv or serviceconf to configure which services start at boot time Refer to Chapter 8 for details 10 4 Additional Resources This chapter discusses the basics of using NFS For more detailed information refer to the following resources 10 4 1 Installed Documentation The man pages for nfsd mountd exports au
290. t Edit its configuration to modify this setting Compression PPP options login name password and more can be changed When the device is added it is not activated as seen by its Inactive status To activate the device select it from the device list and click the Activate button Chapter 6 Network Configuration 77 6 4 Establishing a Modem Connection A modem can be used to configure an Internet connection over an active phone line An Internet Service Provider ISP account also called a dial up account is required To add a modem connection follow these steps 1 Click the Devices tab 2 Click the Add button 3 Select Modem connection from the Device Type list and click Next 4 If there is a modem already configured in the hardware list on the Hardware tab Network Administration Tool assumes you want to use it to establish a modem con nection If there is not modem already configured it tries to detect any modems in the system This probe might take a while 5 After probing the window in Figure 6 5 appears Select Modem Modem Properties Modem Device dew modem Baud Rate 115200 Elow Control Hardware CRTSCTS Modem Volume Off IZ Use touch tone dialing lt Back X Cancel Figure 6 5 Modem Settings 6 Configure the baud rate flow control and modem volume If you do not know these values accept the defaults If you do not have touch tone dialing uncheck the corre spond
291. t Dell P791 Dell P991 Dell Super VGA o I Specify hsync and vsync instead of monitor Ha nc Save File X Cancel Help Figure 2 11 X Configuration Monitor 2 9 Package Selection Basic Configuration Package Group Selection Boot Loader Options Installation Method Partition Information I Classic X Window System Network Configuration I X Window System Authentication Firewall Configuration 7 GNOME I Printing Support X Configuration KDE Pe tion m Pre Installation Script Sound and Multimedia Support Post Installation Script I Network Support Dialup Support I Messaging and Web Tools I Graphics and Image Manipulation News Server T NFS File Server P Windows File Server Anonymous FTP Server I SQL Database Server bee z Save File X Cancel Figure 2 12 Package Selection 53 The Package Selection window allows you to choose which package categories to install Currently Kickstart Configurator does not allow you to select individual packages To in stall individual packages modify the packages section of the kickstart file after you save it 54 Chapter 2 Kickstart Configurator 2 10 Pre Installation Script File Help Basic Configuration Pre Installation Script Boot Loader Options Warning An error in this script might cause your kickstart installation Installation Method to fail Do not include the pre command at the beginnin
292. t Linux you are running download the appropriate packages using one of these methods If you used Red Hat Network to upgrade your kernel automatically you are finished just reboot your system to use the new kernel If you just downloaded the RPM packages from the Red Hat Linux errata page or from Red Hat Network proceed to Section 23 4 23 4 Performing the Upgrade Now that you have the necessary kernel RPM packages you can upgrade your existing ker nel At a shell prompt as root change to the directory that contains the kernel RPM packages and follow these steps You probably want to keep the older kernel in case you have problems with the new kernel Use the i argument instead of u to install the kernel package the kernel version and x86 version might vary rpm ivh kernel1 2 4 18 0 12 1386 rpm If the system is a multi processor system install the kernel smp packages as well the kernel version and x86 version might vary rpm ivh kernel smp 2 4 18 0 12 1386 rpm If the system is i686 based and contains more than 4 gigabytes of RAM install the kernel bigmem package built for the i686 architecture as well the kernel version might vary rpm ivh kernel bigmem 2 4 18 0 12 i1686 rpm If you plan to upgrade the kernel source kernel docs or kernel utils packages you probably do not need to keep the older versions Use the following commands to upgrade these packages the versions might vary rpm Uvh kernel source 2
293. t share the same physical network should be declared within a shared network declaration as shown in Example 12 2 Parameters within the shared network but outside the enclosed subnet declarations are considered global parameters The name of the shared network should be a descriptive title for the network such as test lab to describe all the subnets in a test lab environment Example 12 2 Shared network Declaration shared network name option domain name test redhat com option domain name servers nsl redhat com ns2 redhat com option routers 1 92 168 1 254 more parameters for EXAMPLE shared network subnet 192 168 1 0 netmask 255 255 255 0 parameters for subnet range 192 168 1 1 192 168 1 31 subnet 192 168 1 32 netmask 255 255 255 0 parameters for subnet range 192 168 1 33 192 168 1 63 As demonstrated in Example 12 3 the group declaration can be used to apply global pa rameters to a group of declarations You can group shared networks subnets hosts or other groups Chapter 12 Dynamic Host Configuration Protocol DHCP 113 Example 12 3 Group Declaration group option routers 192 168 1 254 option subnet mask 255 255 255 207 option domain name example com option domain name servers 192 68 1 13 option time offset 53 Eastern Standard Time host apex option host name apex example com hardware ethernet 00 A0 78 8E 9E AA fixed address 192 168 1 4 host raleigh option host name rale
294. tallation For example to set the language to English the kickstart file should contain the following line lang en_US Valid language codes are the following please note that these are subject to change at any time cs_CZ da_DK en_US fr_FR de_DE is_IS it_IT ja_JP eucJP ko_KR eucKR no_NO pt_PT ru_RU koi8r sl_SI es_ES sv_SE uk_UA Chapter 1 Kickstart Installations 27 1 4 14 langsupport langsupport required Sets the language s to install on the system The same language codes used with lang can be used with langsupport If you just want to install one language specify it For example to install and use the French language fr_FR langsupport fr_FR default If you want to install language support for more than one language you must spec ify a default For example to install English and French and use English as the default language langsupport default en_US fr_FR If you use default with only one language all languages will be installed with the specified language set to the default 1 4 15 lilo lilo replaced by boot loader warning This option has been replaced by bootloader and is only available for backwards compatibility Refer to Section 1 4 3 Specifies how the boot loader should be installed on the system By default LILO in stalls on the MBR of the first disk and installs a dual boot system if a DOS partition is found the DOS Windows system will boot if the u
295. talled install it from your Red Hat CD ROM set from a Red Hat FTP mirror site or using Red Hat Network 2 If you do not have an Xclients file you can run switchdesk to create it In your Xclients file edit the following line exec SHOME Xclients default Change the line so that it instead reads exec usr bin ssh agent HOME Xclients default 3 Open the GNOME Control Center GNOME Main Menu Button gt Programs gt Set tings gt GNOME Control Center and go to Session gt Startup Programs Click Add and enter usr bin ssh add in the Startup Command text area Set it a priority to a number higher than any existing commands to ensure that it is executed last A good priority number for ssh add is 70 or higher The higher the priority number the lower the priority If you have other programs listed this one should have the lowest priority Click OK to save your settings and exit the GNOME Control Center 4 Log out and then log back into GNOME in other words restart X After GNOME is started a dialog box will appear prompting you for your passphrase s Enter the passphrase requested If you have both DSA and RSA key pairs configured you will 1 The stands for the home directory of the currently logged in user See the Official Red Hat Linux Getting Started Guide for more details 102 Chapter 9 OpenSSH be prompted for both From this point on you should not be prompted for a password by ssh scp Or sftp 9 3
296. tart file and must start with the post command rote If you configured the network with static IP information including a nameserver you can access the network and resolve IP addresses in the spost section If you configured the network for DHCP the etc resolv conf file has not been completed when the installation executes the spost section You can access the network but you can not resolve IP addresses Thus if you are using DHCP you must specify IP addresses in the spost section Here is an example post section that creates a message of the day file containing the date that the kickstart installation took place and gets around the net work command s limitation of one nameserver only by adding another nameserver to etc resolv conf Spost add comment to etc motd 38 Chapter 1 Kickstart Installations echo Kickstart installed Red Hat Linux bin date gt etc motd add another nameserver echo nameserver 10 10 0 2 gt gt etc resolv conf ote The post install script is run in a chroot environment therefore performing tasks such as copying scripts or RPMs from the installation media will not work nochroot Allows you to specify commands that you would like to run outside of the chroot envi ronment The following example copies the file etc resolv conf to the filesystem that was just installed Spost nochroot cp etc resolv conf mnt sysimage etc resolv conf interpreter usr bin perl
297. ter the password 2 Select Red Hat Linux with the version of the kernel that you wish to boot and type e for edit You will be presented with a list of items in the configuration file for the title you just selected 3 Select the line that starts with kernel and type e to edit the line 4 Go to the end of the line and type single as a separate word press the Spacebar and then type single Press Enter to exit edit mode 62 Chapter 3 Rescue Mode 5 Back at the GRUB screen type b to boot into single user mode If you are using LILO specify one of these options at the LILO boot prompt if you are using the graphical LILO you must press Ctrl x to exit the graphical screen and go to the boot prompt boot linux single boot linux emergency In single user mode you computer boots to runlevel 1 Your local filesystems will be mounted but your network will not be activated You will have a usable system maintenance shell In emergency mode you are booted into the most minimal environment possible The root filesystem will be mounted read only and almost nothing will be set up The main advan tage of emergency mode over linux single is that your init files are not loaded If init is corrupted or not working you can still mount filesystems to recover data that could be lost during a re installation Have you ever rebuilt a kernel and eager to try out your new handiwork rebooted before running sbin 1ilo If you did not
298. the Delete button Chapter 13 Apache Configuration 121 w Listen to all addresses D A Address 192 168 1 4 Q Port 80 Bok X Cancel Figure 13 2 Available Addresses rip If you set Apache to listen to a port under 1024 you must be root to start it For port 1024 and above httpd can be started as a regular user 13 2 Default Settings After defining the Server Name Webmaster email address and Available Addresses click the Virtual Hosts tab and click the Edit Default Settings button The window shown in Figure 13 3 will appear Configure the default settings for your Web server in this window If you add a virtual host the settings you configure for the virtual host take precedence for that virtual host For a directive not defined within the virtual host settings the default value is used 13 2 1 Site Configuration The default values for the Directory Page Search List and Error Pages will work for most servers If you are unsure of these settings do not modify them 122 Chapter 13 Apache Configuration Site Configuration Directory Page Search List Logging Add Environment Variables index htm Directories index shtml Edit Delete List of files to search for when a directory is requested Eg index html index shtml etc Error Pages Bad Request default Authorization Required default Forbidden default Not Found default Method Not Allowed default Not Acceptable default Deka Adana ai Saas
299. ting 83 Ethernet connection 74 activating 75 ISDN connection 75 activating 76 managing etc hosts 83 managing DNS Settings 84 managing hosts 83 modem connection 77 activating 78 overview 73 token ring connection 80 activating 81 wireless connection 82 xDSL connection 78 activating 79 Network File System See NFS NFS etc fstab 103 additional resources 106 autofs See autofs configuration 103 exporting 105 mounting 103 starting the server 105 status of the server 105 stopping the server 105 ntsysv 94 0 O Reilly amp Associates Inc 106 136 260 OpenSSH 97 etc ssh sshd_config 97 additional resources 102 authorization key pairs 99 client 97 scp 98 server 97 starting and stopping 97 sftp 99 ssh 97 ssh keygen DSA 99 RSA 100 100 OpenSSL additional resources 102 P packages dependencies 219 determining file ownership with 225 finding deleted files from 225 freshening with RPM 221 installing 218 with Gnome RPM 232 locating documentation for 225 obtaining list of files 226 preserving configuration files 220 querying 221 querying uninstalled 226 querying with Gnome RPM 238 removing 220 secure server choosing for installation 137 selecting with Gnome RPM 231 tips 225 uninstalling with Gnome RPM 240 upgrading 220 upgrading with Gnome RPM 241 verifying 222 verifying with Gnome RPM 238 239 pam_smbpass 108 PCI devices viewing 176 port nu
300. tings page choose between DHCP and static IP ad dress You may specify a hostname for the device If the device receives a dynamic IP address each time the network is started do not specify a hostname Click Next to continue 7 Click Finish on the Create Ethernet Device page After configuring the token ring device it appears in the device list as shown in Figure 6 10 Chapter 6 Network Configuration Devices Hardware Hosts ONS You may configure network devices associated with physical hardware here Multiple logical devices can be associated with a single piece of hardware Status Device Nickname Type Add Edit Copy Delete Activate Deactivate Hie EEE Monitor P Hep _ Y apy _ x Close Figure 6 10 Token Ring Device Be sure to click Apply to save the changes 81 After adding the device you can edit its configuration by selecting the device from the device list and clicking Edit For example you can configure whether the device is started at boot time When the device is added it is not activated as seen by its Inactive status To activate the device select it from the device list and click the Activate button 6 7 Establishing a CIPE Connection CIPE stands for Crypto IP Encapsulation It is used to configure an IP tunneling device For example CIPE can be used to grant access from the outside world into a Virtual Private Network VPN If yo
301. tion or choose an everything installation to install all packages To do this simply add one of the following lines to the packages section 1 This option is new to Red Hat Linux 7 3 1 This option is new to Red Hat Linux 7 3 Chapter 1 Kickstart Installations 37 GNOME KDE Server Everything Qe eae 1 4 30 spre Pre Installation Configuration Section You can add commands to run on the system immediately after the ks cfg has been parsed This section must be at the end of the kickstart file after the commands and must start with the spre command Note that you can access the network in the spre section however name service has not been configured at this point so only IP addresses will work Here is an example pre section Spre add comment to etc motd echo Kickstart installed Red Hat Linux bin date gt etc motd add another nameserver echo nameserver 10 10 0 2 gt gt etc resolv conf This section creates a message of the day file containing the date the kickstart installation took place It also gets around the network command s limitation of only one name server by adding another nameserver to etc resolv conf rote Note that the pre install script is not run in the change root environment 1 4 31 spost Post Installation Configuration Section You have the option of adding commands to run on the system once the installation is com plete This section must be at the end of the kicks
302. to master and autofs in manual sections 5 and 8 These man pages show the correct syntax for the NFS and autofs configuration files 10 4 2 Related Books e Managing NES and NIS Services by Hal Stern O Reilly amp Associates Inc 3 redhat Chapter 11 Samba Samba uses the SMB protocol to share files and printers across a network connection Oper ating systems that support this protocol include Microsoft Windows through its Network Neighborhood OS 2 and Linux 11 1 Why Use Samba Samba is useful if you have a network of both Windows and Linux machines Samba will allow files and printers to be shared by all the systems in your network If you want to share files between Red Hat Linux machines only refer to Chapter 10 If you want to share printers between Red Hat Linux machines only refer to Chapter 21 11 2 Configuring Samba Samba uses etc samba smb conf as its configuration file If you change this configuration file the changes will not take effect until you restart the Samba daemon with the command service smb restart The default configuration file smb conf in Red Hat Linux 7 3 allows users to view their Linux home directories as a Samba share on the Windows machine after they log in using the same username and password It also shares any printers configured for the Red Hat Linux system as Samba shared printers In other words you can attach a printer to your Red Hat Linux system and print to it from t
303. to save your Apache configuration settings click the Cancel button in the bottom right corner of the Apache Configuration Tool window You will be prompted to confirm this decision If you click Yes to confirm this choice your settings will not be saved If you want to save your Apache configuration settings click the OK button in the bottom right corner of the Apache Configuration Tool window The dialog window shown in Figure 13 15 will appear If you answer Yes your settings will be saved in etc httpd conf httpd conf Remember that your original configuration file will be overwritten 0 Are you sure you want to save and exit Q Ove Figure 13 15 Save and Exit If this is the first time that you have used the Apache Configuration Tool you will see the dialog window shown in Figure 13 16 warning you that the configuration file has been manually modified If the Apache Configuration Tool detects that the httpd conf configuration file has been manually modified it will save the manually modified file as etc httpd conf httpd conf bak Q The configuration file has been manually modified Overwrite Bex Figure 13 16 Configuration File Manually Modified i eee After saving your settings you must restart the Apache daemon with the command service httpd restart You must be logged in as root to execute this command 136 Chapter 13 Apache Configuration 13 7 Additional Resources To learn more about Apache refer
304. to the following resources 13 7 1 Installed Documentation e Apache documentation If you have the apache manual package installed and the Apache Web server daemon httpd running you can view the Apache documentation Open a Web browser and go to the URL http localhost on the server that is running Apache Then click the Documentation link 13 7 2 Useful Websites http www apache org The Apache Software Foundation http httpd apache org docs Apache HTTP Server Version 1 3 User s Guide http localhost manual index html After starting the Apache server on your local system you can view the Apache HTTP Server Version 1 3 User s Guide using this URL http www redhat com support docs apache html Red Hat Support maintains a list of useful Apace Web Server links http www redhat com support docs faqs RH apache FAQ book1 html The Red Hat Linux Apache Centralized Knowledgebase compiled by Red Hat 13 7 3 Related Books e Apache The Definitive Guide by Ben Laurie and Peter Laurie O Reilly amp Associates Inc 3 redhat Chapter 14 Apache Secure Server Configuration 14 1 Introduction This chapter provides basic information on an Apache server with the mod_ss1 security module enabled to use the OpenSSL library and toolkit The combination of these three components provided with Red Hat Linux will be referred to in this chapter as the secure Web server or just as the secure server
305. to use the driverdisk command to tell the installation program where to look for the driver disk driverdisk lt partition gt type lt fstype gt lt partition gt is the partition containing the driver disk type Filesystem type for example vfat ext2 or ext3 1 4 8 firewall firewall optional Firewall options can be configured in kickstart This configuration corresponds to the Firewall Configuration screen in the installation program 24 Chapter 1 Kickstart Installations firewall high medium disabled trust lt device gt dhcp ssh telnet smtp http ftp port lt portspec gt Levels of security Choose one of the following levels of security e high e medium e disabled trust lt device gt Listing a device here such as eth0 allows all traffic coming from that device to go through the firewall To list more than one device use trust eth0 trust ethl Do NOT use a comma separated format such as trust eth0 ethl Allow incoming Enabling these options allow the specified services to pass through the firewall e dhcp v ssh telnet smtp e http tp port lt portspec gt You can specify that ports be allowed through the firewall using the port protocol for mat For example if you wanted to allow IMAP access through your firewall you can specify imap tcp You can also specify numeric ports explicitly for example
306. ts its reputation behind its certification of your organi zation s identity When your browser is communicating using SSL encryption you will see the https prefix at the beginning of the Uniform Resource Locator URL in the navigation bar Encryption depends upon the use of keys think of them as secret encoder decoder rings in data format In conventional or symmetric cryptography both ends of the transaction have the same key which they use to decode each other s transmissions In public or asymmetric cryptography two keys co exist a public key and a private key A person or an organization keeps their private key a secret and publishes their public key Data encoded with the public key can only be decoded with the private key data encoded with the private key can only be decoded with the public key To set up your secure server you will use public cryptography to create a public and private key pair In most cases you will send your certificate request including your public key proof of your company s identity and payment to a CA The CA will verify the certificate request and your identity and then send back a certificate for your secure Web server 140 Chapter 14 Apache Secure Server Configuration A secure server uses a certificate to identify itself to Web browsers You can generate your own certificate called a self signed certificate or you can get a certificate from a Certificate Authority or CA A certificate
307. ttings Clicking the Ok button will apply the changes and then exit the program 18 2 Time Zone Configuration To configure the system time zone click the Time Zone tab as shown in Figure 18 2 The time zone can be changed by either using the interactive map or by choosing the desired time zone from the list below the map To use the map click on the city that represents the desired time zone A red X will appear and the time zone selection will change in the list below the map Click Apply to save the changes Click Ok to apply the changes and exit the program If your system clock is set to use UTC select the System clock uses UTC option UTC stands for the universal time zone also known as Greenwich mean time GMT Other time zones are determined by adding or subtracting from the UTC time Date amp Time Fime Zone View World I System clock uses UTC Ontario amp Quebec a America Montreal Eastern Time America Montserrat America Nassau America New_York Eastern Time America Nipigon Eastern Time Ontario amp Quebec America Nome Alaska Time west Alaska America Noronha Atlantic islands bad gt Pox X cancel Apply Help Figure 18 2 Timezone Configuration 166 Chapter 18 Time and Date Configuration SS redhat Chapter 19 User and Group Configuration User Manager allows you to view modify add and delete local users and groups To use User Manager you m
308. tton 80 Chapter 6 Network Configuration 6 6 Establishing a Token Ring Connection A token ring network is a network in which all the computers are connected in a circular pattern A token or a special network packet travels around the token ring and allows com puters to send information to each other Ori For more information on using token ring under Linux refer to the Linux Token Ring Project website available at http www linuxtr net To add a token ring connection follow these steps 1 Click the Devices tab 2 Click the Add button 3 Select Token Ring connection from the Device Type list and click Next 4 If you have already added the token ring card to the hardware list select it from the Ethernet card list Otherwise select Other Tokenring Card to add the hardware device 5 If you selected Other Tokenring Card the Select Token Ring Adapter window as shown in Figure 6 9 appears Select the manufacturer and model of the adapter Select the device name If this is the system s first token ring card select tr0 if this is the second token ring card select tr1 and so on The Network Administration Tool also allows the user to configure the resources for the adapter Click Next to continue Select Token Ring Adapter Adapter IBM Olympic based PCI roken ring Device fro Resource IRQ Unknown MEM lt Back X Cancel Figure 6 9 Token Ring Settings 6 On the Configure Network Set
309. ttpd conf 119 etc printcap 179 etc printcap local 179 etc sysconfig dhepd 115 etc sysconfig ipchains 87 90 proc directory 177 var spool cron 198 A anacron additional resources 202 Apache 119 See Also Apache Configuration Tool additional resources 136 related books 136 securing 139 Apache Configuration Tool Directives See Apache directives error log 123 Modules 119 transfer log 123 Apache directives DirectoryIndex 122 ErrorDocument 122 ErrorLog 123 Group 133 HostnameLookups 124 KeepAlive 134 KeepAliveTimeout 134 Listen 120 LogFormat 123 LogLevel 123 MaxClients 134 MaxKeepAliveRequests 134 Options 122 ServerAdmin 120 ServerName 120 TimeOut 134 TransferLog 123 User 133 apacheconf 119 APXS 138 at 200 additional resources 202 autofs 104 etc auto master 104 Automated Tasks 197 B batch 200 additional resources 202 BIND configuration 149 adding a forward master zone 150 adding a reverse master zone 152 adding a slave zone 154 applying changes 150 default directory 150 bindconf 149 boot diskette 205 booting emergency mode 61 rescue mode 59 single user mode 61 Cc CA See certificate authorities certificate authorities choosing 141 creation of request 143 installing 146 moving it after an upgrade 140 pre existing 140 request creation of 143 self signed 145 test vs signed vs self signed 141 testing 146 chkconfig 95
310. twork Rpmfind Distributions Install Options Other Options No dependency checks _j Don install documentation I No reordering Install all files I Don t run scripts Database Options Upgrade Options _ Just update database i Allow replacement of packages al Just test l Allow replacement of files Architecture Options Allow upgrade to old version _ Dont check package architecture i Keep packages made obsolete _ Don t check package OS Bok y Apply X Close Help Figure 26 4 Behaviour Tab in Preferences Under Install Options you have the following choices e No dependency checks When selected this will install or upgrade a package with out checking for other files that the program may depend on in order to work Unless you know what you are doing we strongly suggest that you not use this option as some packages may depend on other packages in order to function correctly No reordering This option is useful if RPM is unable to change the installation order of some packages to satisfy dependencies Do not run scripts Pre and post install scripts are sequences of commands that are sometimes included in packages to assist with installation Selecting this option is similar to the noscripts option when installing packages from the shell prompt Under Upgrade Options you can select the following Allow replacement of packages Replaces a package with a new copy of the same pack age Sim
311. ty of Software RAID level 4 is equal to the capacity of the member partitions minus the size of one of the partitions if they are of equal size Level 5 This is the most common type of RAID By distributing parity across some or all of an array s member disk drives RAID level 5 eliminates the write bottleneck inherent in level 4 The only performance bottleneck is the parity calculation process With mod ern CPUs and Software RAID that usually isn t a very big problem As with level 4 the result is asymmetrical performance with reads substantially outperforming writes Level 5 is often used with write back caching to reduce the asymmetry The storage capacity of Hardware RAID level 5 is equal to the capacity of member disks minus the capacity of one member disk The storage capacity of Software RAID level 5 is equal to the capacity of the member partitions minus the size of one of the partitions if they are of equal size Linear RAID Linear RAID is a simple grouping of drives to create a larger virtual drive In linear RAID the chunks are allocated sequentially from one member drive going to the next drive only when the first is completely filled This grouping provides no performance benefit as it is unlikely that any I O operations will be split between member drives Linear RAID also offers no redundancy and in fact decreases reliability if any one member drive fails the entire array cannot be used The capacity is the tot
312. u can configure Apache directives such as virtual hosts logging attributes and maximum number of connections Only modules that are shipped with Red Hat Linux can be configured with Apache Con figuration Tool If additional modules are installed they can not be configured using this tool The Apache Configuration Tool requires the X Window System and root access To start the Apache Configuration Tool use one of the following methods e On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt Apache Configuration On the KDE desktop go to the Main Menu Button on the Panel gt System gt Apache Configuration Type the command apachecon at a shell prompt for example in an XTerm or GNOME terminal Efon Do not edit the etc httpd conf httpd conf Apache configuration file if you wish to use this tool Apache Configuration Tool generates this file after you save your changes and exit the program If you want to add additional modules or configuration options that are not available in Apache Con figuration Tool you cannot use this tool The general steps for configuring the Apache Web Server using the Apache Configuration Tool are as following 1 Configure the basic settings under the Main tab 2 Click on the Virtual Hosts tab and configure the default settings 3 Under the Virtual Hosts tab configure the Default Virtual Host 4 If you want to serve more than one URL o
313. u need to setup a CIPE device contact your system administrator for the correct values Configure Tunnel Device cipcho Tunnel through Device None Server Mode Local Port Remote Peer Address Remote Peer Port Remote Virtual Address Local Virtual Address Secret Key Generate Configuration for your remote partner P Address of Tunnel Device Server Mode lLocal Port own choice Remote Peer Address 0 0 0 0 auto Remote Virtual Address Local Virtual Address Secret Key lt Back X Cancel Figure 6 11 CIPE Settings 82 Chapter 6 Network Configuration 6 8 Establishing a Wireless Connection Wireless Ethernet devices are becoming increasingly popular The configuration is similar to the Ethernet configuration except that it allows you to configure ESSID mode frequency channel transmit rate and key for your wireless device To add a wireless Ethernet connection follow these steps 1 Click the Devices tab 2 Click the Add button 3 Select Wireless connection from the Device Type list and click Next 4 If you have already added the wireless network interface card to the hardware list select it from the Ethernet card list Otherwise select Other Ethernet Card to add the hardware device rote The installation program usually detects supported wireless Ethernet devices and prompts you to configure them If you configured them during the insta
314. u to the graphical login screen or the console text found on a GUI interface A title word or phrase found on a GUI interface screen or window will be shown in this style When you see text shown in this style it is being used to identify a particular GUI screen or an element on a GUI screen such as text associated with a checkbox or field Example Select the Require Password checkbox if you would like your screensaver to require a password before stopping xii Introduction top level of a menu on a GUI screen or window When you see a word in this style it indicates that the word is the top level of a pull down menu If you click on the word on the GUI screen the rest of the menu should appear For example Under Settings on a GNOME terminal you will see the following menu items Prefer ences Reset Terminal Reset and Clear and Color selector If you need to type in a sequence of commands from a GUI menu they will be shown like the following example Click on Programs gt A pplications gt Emacs to start the Emacs text editor button on a GUI screen or window This style indicates that the text will be found on a clickable button on a GUI screen For example Click on the Back button to return to the webpage you last viewed computer output When you see text in this style it indicates text displayed by the computer on the command line You will see responses to commands you typed in error messages and inte
315. ulfilled the CA s requirements they will send a certificate to you usually by email Save or cut and paste the certificate that they send you as etc httpd conf ssl crt server crt 14 8 Creating a Self Signed Certificate You can create your own self signed certificate Please note that a self signed certificate will not provide the security guarantees provided by a CA signed certificate See Section 14 5 for more details about certificates If you would like to make your own self signed certificate you will first need to create a random key using the instructions provided in Section 14 6 Once you have a key use the following command make testcert You will see the following output and you will be prompted for your password unless you generated a key without a password umask 77 usr bin openssl req new key etc httpd conf ssl key server key x509 days 365 out etc httpd conf ssl crt server crt Using configuration from usr share ssl openssl cnf Enter PEM pass phrase After you enter your password or without a prompt if you created a key without a pass word you will be asked for more information The computer s output and a set of inputs looks like the following you will need to provide the correct information for your organiza tion and host You are about to be asked to enter information that will be incorporated into your certificate request What you are about to enter is what is called a Distinguishe
316. user password servername sharename 11 4 Additional Resources For configuration options not covered here please refer to the following resources 11 4 1 Installed Documentation e smb conf man page explains how to configure the Samba configuration file e smbd man page describes how the Samba daemon works e usr share doc samba version number docs HTML and text help files included with the samba package 11 4 2 Useful Websites http www samba org The Samba Web page contains useful documentation informa tion about mailing lists and a list of GUI interfaces 3 redhat Chapter 12 Dynamic Host Configuration Protocol DHCP Dynamic Host Configuration Protocol DHCP is network protocol for automatically assign ing TCP IP information to client machines Each DHCP client connects to the centrally located DHCP server which returns that client s network configuration including IP address gateway and DNS servers 12 1 Why Use DHCP DHCP is useful for fast delivery of client network configuration When configuring the client system the administrator can choose DHCP and not have to enter an IP address netmask gateway or DNS servers The client retrieves this information from the DHCP server DHCP is also useful if an administrator wants to change the IP addresses of a large number of sys tems Instead of reconfiguring all the systems he can just edit one DHCP configuration file on the server for the ne
317. ust be running the X Window System and have root privileges To start User Manager use one of the following methods e On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt User Manager e On the KDE desktop go to the Main Menu Button on the Panel gt System gt redhat config users e Type the command redhat config users ata shell prompt for example in an XTerm or a GNOME terminal Action Preferences Help kB gt 0 New User New Group Properties Delete Help Refresh Apply filter Users Groups User Name User ID Primary Group Full Name Login Shell Home Directory 00 tfox SI tfox dbintbash thomeitfox irfuller 501 irfuller jbindbash Mmome r fuller iha 502 iha jbintoash Mhome ha Figure 19 1 Red Hat User Manager To view a list of all local users on the system click the Users tab To view a list of all local groups on the system click the Groups tab If you need to find a specific user or group type the first few letters of the name in the Filter by field Press Enter or click the Apply filter button The filtered list will be displayed To sort the users or groups click on the column name The users or groups will be sorted by the value of that column Red Hat Linux reserves user IDs above 500 for system users By default Red Hat User Man ager does not display system users To view all users including the system users uncheck Preference
318. w set of IP address If the DNS servers for an organization changes the changes are made on the DHCP server not on the DHCP clients Once the network is restarted on the clients or the clients are rebooted the changes will take effect Furthermore if a laptop or any type of mobile computer is configured for DHCP it can be moved from office to office without being reconfigured as long as each office has a DHCP server that allows it to connect to the network 12 2 Configuring a DHCP Server You can configure a DHCP server using the configuration file etc dhcpd conf DHCP also uses the file var 1ib dhcp dhcpd leases to store the client lease database Refer to Section 12 2 2 for more information 12 2 1 Configuration File The first step in configuring a DHCP server is to create the configuration file that stores the network information for the clients Global options can be declared for all clients or options can be declared for each client system The configuration file can contain any extra tabs or blank lines for easier formatting The keywords are case insensitive and lines beginning with a hash mark are considered com ments There are two types of statements in the configuration file e Parameters state how to perform a task whether to perform a task or what network configuration options to sent to the client e Declarations describe the topology of the network describe the clients provide ad dresses f
319. wing saving etc foo conf as etc foo conf rpmsave Chapter 25 Package Management with RPM 221 This message means that your changes to the configuration file may not be forward com patible with the new configuration file in the package so RPM saved your original file and installed a new one You should investigate the differences between the two configuration files and resolve them as soon as possible to ensure that your system continues to function properly Upgrading is really a combination of uninstalling and installing so during an RPM upgrade you can encounter uninstalling and installing errors plus one more If RPM thinks you are trying to upgrade to a package with an older version number you will see rpm Uvh foo 1 0 1 1386 rpm foo package foo 2 0 1 which is newer is already installed To cause RPM to upgrade anyway use the oldpackage option rpm Uvh oldpackage foo 1 0 1 i386 rpm foo PREAH E AE AE FE FE AE AE FE FE AE FE FE E FE FE AE AE E AE AE FE FE FE AE AE FE FE AE FEAE E 25 2 5 Freshening Freshening a package is similar to upgrading one Type the following command at a shell prompt rpm Fvh foo 1 2 1 i386 rpm foo FEAE AE AE AE FEAE AE AE FEAE E AE FEE HE AE HE EH aH EEEE RPM s freshen option checks the versions of the packages specified on the command line against the versions of packages that have already been installed on your system When a newer version of an already installed p
320. with RPM The Red Hat Package Manager RPM is an open packaging system available for anyone to use which runs on Red Hat Linux as well as other Linux and UNIX systems Red Hat Inc encourages other vendors to use RPM for their own products RPM is distributable under the terms of the GPL For the end user RPM makes system updates easy Installing uninstalling and upgrading RPM packages can be accomplished with short commands RPM maintains a database of installed packages and their files so you can invoke powerful queries and verifications on your system If you prefer a graphical interface you can use Gnome RPM to perform many RPM commands During upgrades RPM handles configuration files carefully so that you never lose your customizations something that you will not accomplish with regular tar gz files For the developer RPM allows you to take software source code and package it into source and binary packages for end users This process is quite simple and is driven from a single file and optional patches that you create This clear delineation of pristine sources and your patches and build instructions eases the maintenance of the package as new versions of the software are released rote Because RPM makes changes to your system you must be root in order to install remove or upgrade an RPM package 25 1 RPM Design Goals In order to understand how to use RPM it can be helpful to understand RPM s design goals
321. x 7 3 provides two MTAs Sendmail and Postfix If both are installed sendmail is the default MTA Red Hat Mail Transport Agent Switcher allows a user to select either sendmail or post fix as the default MTA for the system To start Red Hat Mail Transport Agent Switcher use one of the following methods e On the GNOME desktop go to the Main Menu Button on the Panel gt Programs gt System gt Red Hat Mail Transport Agent Switcher e On the KDE desktop go to the Main Menu Button on the Panel System gt Red Hat Mail Transport Agent Switcher e Type the command redhat switchmail at a shell prompt for example in an XTerm or GNOME terminal The program automatically detect if the X Window System is running If it is running the program starts in graphical mode as shown in Figure 16 1 If X is not detected it starts in text mode To force Red Hat Mail Transport Agent Switch to run in text mode use the command redhat switchmail nox The Mail Transport Agent Switcher is a tool which enables users to easily switch between various Mail Transport Agent that they have installed Please choose your Mail transport agent Available Mail Transport Agent Sendmail C Postfix ox X Cancel Figure 16 1 Red Hat Mail Transport Agent Switcher 156 Chapter 16 Mail Transport Agent MTA Configuration If you selected Postfix you must make sure the sendmail service is stopped and the post fix service is started sbi
322. xecute a custom script that you wrote For any of the above values an asterisk can be used to specify all valid values For ex ample an asterisk for the month value means execute the command every month within the constraints of the other values A hyphen between integers specifies a range of integers For example 1 4 means the integers 1 2 3 and 4 A list of values separated by commas specifies a list Forexample 3 4 6 8 indicates those four specific integers The forward slash can be used to specify step values The value of an integer can be skipped within a range by following the range with lt integer gt For example 0 59 2 can be used to define every other minute in the minute field Step values can also be used with an asterisk For instance the value 3 can be used in the month field to run the task every third month Any lines that begin with a hash mark are comments and are not processed Example 22 1 Examples of crontabs record the memory usage of the system every monday at 3 30AM in the file tmp meminfo 30 3 mon cat proc meminfo gt gt tmp meminfo run custom script the first day of every month at 4 10AM 10 41 root scripts backup sh As you can see from the etc crontab file it uses the run parts script to execute the scripts inthe etc cron hourly etc cron daily etc cron weekly and etc cron monthly directories on an hourly daily weekly or monthly basis respectiv
323. y kickstart displays a message and waits for the user to press a key before rebooting 1 4 22 rootpw root pw required rootpw iscrypted lt password gt Sets the system s root password to the lt password gt argument iscrypted If this is present the password argument is assumed to already be encrypted 1 4 23 skipx skipx optional If present X is not configured on the installed system 34 Chapter 1 Kickstart Installations 1 4 24 text text optional Perform the kickstart installation in text mode Kickstart installations are performed in graphical mode by default 1 4 25 timezone timezone required timezone utc lt timezone gt Sets the system time zone to lt t imezone gt which may be any of the time zones listed by timeconfig utc If present the system assumes the hardware clock is set to UTC Greenwich Mean time 1 4 26 upgrade upgrade optional Tells the system to upgrade an existing system rather than install a fresh system 1 4 27 xconfig xconfig optional Configures the X Window System If this option is not given the user will need to con figure X manually during the installation if X was installed this option should not be used if X is not installed on the final system noprobe Do not probe the monitor card lt card gt Use card lt card gt this card name should be from the list of cards in Xconfigurator If this argument is not provide
324. y without requiring your recipient to decrypt your entire message In a clearsigned message your signature appears as a text block within the context of your letter a detached signature is sent as a separate file with your correspondence B 7 Additional Resources There is more to encryption technology than can be covered in one slim introduction to GnuPG Here are some resources where you can learn more 260 Appendix B Getting Started with Gnu Privacy Guard B 7 1 Installed Documentation e man gpgand info gpg Quick Reference of GnuPG commands and options B 7 2 Useful Websites http www gnupg org The GnuPG website with links to the latest GnuPG releases a comprehensive user s guide and other cryptography resources http hotwired lycos com webmonkey backend security tutorials tutoriall html Visit the Encryption Tutorial from Webmonkey to learn more about encryption and how to apply encryption techniques http www eff org pub Privacy The Electronic Frontier Foundation Privacy Secu rity Crypto amp Surveillance Archive B 7 3 Related Books The Official PGP User s Guide by Philip R Zimmerman MIT Press e PGP Pretty Good Privacy by Simson Garfinkel O Reilly amp Associates Inc e E Mail Security How to Keep Your Electronic Messages Private by Bruce Schneier John Wiley amp Sons Index Symbols etc auto master 104 etc fstab 103 etc hosts Ipd etc httpd conf h
325. y access from all hosts L SymLinkslfOwnerMatch w Deny hosts from l Allow List w Allow access from all hosts A Allow hosts from ise 68 1 0 255 255 255 0 _jLet htaccess files override directory options Directory varnvwwhtmitesting Browse Bok X Cancel Help Figure 13 7 Directory Settings If you check the Let htaccess files override directory options the configuration directives in the htaccess file take precedence 13 3 Virtual Hosts Settings You can use the Apache Configuration Tool to configure virtual hosts Virtual hosts allow you to run different servers for different IP addresses different host names or different ports on the same machine For example you can run the website for http www your_domain com and _ http www your_second_domain com on the same Apache server using virtual hosts This option corresponds to the lt VirtualHost gt directive for the default virtual host and IP based virtual hosts It corresponds to the lt NameVirtualHost gt directive for a name based virtual host The Apache directives set for a virtual host only apply to that particular virtual host If a di rective is set server wide using the Edit Default Settings button and not defined within the virtual host settings the default setting is used For example you can define a Webmaster email address in the Main tab and not define individual email addresses for each virtual host Apache Configuration Tool includes
326. ys to execute the command delay delay time in minutes job identifier description of the task used in Anacron messages and as the name of the job s timestamp file can contain any non blank characters except slashes command command to execute For each tasks Anacron determines if the task has been executed within the period specified in the period field of the configuration file If it has not been executed within the given pe riod Anacron executes the command specified in the command field after waiting the number of minutes specified in the delay field 200 Chapter 22 Automated Tasks After the task is completed Anacron records the date in a timestamp file in the var spool anacron directory Only the date is used not the time and the value of the job identifier is used as the filename for the timestamp file Environment variables such as SHELL and PATH can be defined at the top of etc anacrontab as with the cron configuration file The default configuration file looks similar to the following etc anacrontab configuration file for anacron See anacron 8 and anacrontab 5 for details SHELL bin sh PATH usr local sbin usr local bin sbin bin usr sbin usr bin These entries are useful for a Red Hat Linux system 1 5 cron daily run parts etc cron daily 7 10 cron weekly run parts etc cron weekly 30 15 cron monthly run parts etc cron monthly Figure 22 1 Default anacrontab As you can se
327. ys a good idea to confirm that the boot loader has been configured to boot the new kernel This is a crucial step If the boot loader is configured incorrectly you will not be able to boot your system If this hap pens boot your system with the boot diskette you created earlier and try configuring the boot loader again 23 5 1 GRUB If you selected GRUB as your boot loader confirm that the file boot grub grub conf con tains a title section with the same version as the kernel package you just installed if you installed the kerne1 smp and or kernel bigmem you will have a section for it has well NOTICE You have a boot partition This means that all kernel paths are relative to boot default 0 timeout 30 splashimage hd0 0 grub splash xpm gz title Red Hat Linux 2 4 18 0 12 root hd0 0 kernel vmlinuz 2 4 18 0 12 ro root dev hda3 initrd initrd 2 4 18 0 12 img If you created a separate boot partition the paths to the kernel and initrd image are relative to the boot partition You can begin testing your new kernel by rebooting your computer and watching the mes sages to ensure your hardware is detected properly 23 5 2 LILO If you selected LILO as your boot loader confirm that the file etc 1lilo conf contains an image section with the same version as the kernel package you just installed Chapter 23 Ugrading the Kernel 209 boot dev hda map boot map install boot boot b prompt timeout 50 message boot

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