IBM V7.2 User's Manual
Contents
1. G GG EE LUG o ma N Execute the FlashCopy task ts1dbrev from the Primary server as root user usr opt ibm2105cli rsExecuteTask sh v s ESSCSS tsldbdatarevfc Wait for rsExecuteTask to return Mount the db2 TS1 data file systems on the Primary server mount db2 TS1 db2ts1 NODEOOOO mount db2 TS1 sapdatal mount db2 TS1 sapdata2 mount db2 TS1 sapdata3 mount db2 TS1 sapdata4 mount db2 TS1 sapdata5 Split Mirror Restore Scenario 34 mount db2 TS1 sapdata6 mount db2 TS1 sapdata7 9 Start the DB2 instance on the Primary server db2start 10 On the Primary database issue the db2inidb command to take the database image out of a suspended state and place it into a rollforward pending state db2inidb tsl as mirror 11 On the Primary database rollforward through the DB2 logs and stop The rollforward command allows the option to rollforward to end of logs or to rollforward to a point in time db2 rollforward database tsl to end of logs and stop Or db2 rollforward database tsl to 2000 06 19 19 56 00 0000 and stop 12 Start the SAP system TS1 on the Primary server by logging on as user tsiadm and issuing the following command startsap Summary DB2 UDB s Suspend l O technology provides a very powerful mechanism to offload work on to a secondary system as well as providing a means to plan for disaster recovery This functionality along with the utiliz2. The file system for the SAP software is contained in usr sap Note The home directory for the DB2 instance owner must be created manually on each machine and will not utilize any pairs DB2 archive logs do not have to be placed in a pair They are treated and stored as you would normally do as part of your recovery strategy and plan Here are examples of how to create volume groups logical volumes and file systems on the Primary server Create volume groups smit vg gt Add a Volume Group Configuring a Two Host System 18 dd a Volume Group Type or select values in entry fields Press Enter AFTER making all desired changes Entry Fields VOLUME GROUP name Physical partition SIZE in megabytes PHYSICAL VOLUME names Activate volume group AUTOMATICALLY yes at system restart Volume Group MAJOR NUMBER Create VG Concurrent Capable no Auto varyon in Concurrent Mode no Alternatively issue the following command mkvg f y sapvg s 64 hdisk15 smit vg gt Add a Volume Group Add a Volume Group Type or select values in entry fields Press Enter AFTER making all desired changes Entry Fields VOLUME GROUP name dall Physical partition SIZE in megabytes PHYSICAL VOLUME names qq 9 hdisk29 hdisk33l Activate volume group AUTOMATICALLY yes at system restart Volume Group MATOR NUMBER Create VG Concurrent Capable no Auto varyon in Concurrent Mode no Alternatively issue the fol
3. Press Enter AFTER making all desired changes Logical volume NAME VOLUME GROUP name Number of LOGICAL PARTITIONS PHYSICAL VOLUME names Logical volume TYPE POSITION on physical volume RANGE of physical volumes MAXIMUM NUMBER of PHYSICAL VOLUMES to use for allocation Number of COPIES of each logical partition Mirror Write Consistency Allocate each logical partition copy on a SEPARATE physical volume RELOCATE the logical volume during reorganization Logical volume LABEL MAXIMUM NUMBER of LOGICAL PARTITIONS Enable BAD BLOCK relocation SCHEDULING POLICY for reading writing logical partition copies Enable WRITE VERIFY File containing ALLOCATION MAP Stripe Sizer Alternatively issue the following commands mklv y dblv dbvg 60 hdisk26 mklv y datallv dbvg 295 hdisk9 mklv y data2lv dbvg 295 hdisk33 mklv y data3lv dbvg 295 hdisk11 mklv y data4lv dbvg 295 hdisk29 mklv y data5lv dbvg 295 hdisk21 mklv y data6lv dbvg 295 hdisk41 mklv y data7lv dbvg 295 hdisk28 mklv y dbloglv dbvg 295 hdisk34 Create file systems smit fs MS Fields 512 yes parallel no Not Striped gt Add Change Show Delete File Systems gt Journaled File Systems Add a Journaled File System on a Previously Defined Logical Volume Add a Standard Journaled File System Configuring a Two Host System 21 Add a Large File Enabled Journaled File System Type or select values in entr
4. complete execution The command returns 0 for successful completion and greater than zero if there is an error Note For FlashCopy tasks execution is completed when the FlashCopy pairs have been established and the control bitmaps have been generated This usually only lasts a few seconds rsList2105s Displays the mapping of host physical volume name to ESS volume serial number for all disks assigned to the host system from which the command is executed rsPrimeServer Notifies the Copy Services Server of the mapping of host disk name to ESS volume serial number This permits a host volume view from the ESS Copy Services Server Web interface rsQuery Queries the FlashCopy and PPRC status of one or more volumes rsTestConnection Determines whether the Copy Services Server can be contacted successfully rsQueryComplete Determines PPRC status With the exception of rsList2105s all commands require the IP address or complete hostname of the Primary Copy Services Server as parameter Optionally you can specify the address of the Backup Copy Services Server ESS Copy Services CLI Command Description 9 Overview of standard SAP R 3 system installation with DB2 UDB A SAP R 3 system is identified by a three character system identifier lt SID gt and a two digit system number between 00 and 96 The following information about the directory structure applies to a Central System consisting of the SAP R 3 central instance and dat
5. Figure 2 FlashCopy configuration The key points to note from Figure 2 are e The host name of the Primary server is MACHA Configuring a Two Host System 15 the ESS e The Primary server uses the source disks while the Backup server uses the target disks The host name of the Backup server is MACHB The host name of the ESS Copy Services Server is ESSCSS The name of the SAP system is TS1 its system number is 00 To achieve optimal performance the disks are spread equally over all 8 LSSs of e The Primary server accesses the ESS volumes as follows ESS volumes Logical subsystem 009 and 015 10 10A and 110 11 215 12 315 13 407 14 507 15 605 16 707 17 O e These devices are visible to AIX as OvO O OF OO 00 50 O hdisk15 hdisk9 hdisk26 hdisk11 hdisk21 hdisk41 hdisk33 hdisk29 hdisk28 hdisk34 e The Backup server accesses the ESS volumes as follows ESS volumes Logical subsystem 00B and 010 10 10B and 115 11 216 12 316 13 410 14 510 15 612 16 711 17 e These devices are visible to AIX as Q Q9 29 hdisk16 hdisk7 hdisk13 hdisk35 hdisk39 Configuring a Two Host System 16 hdisk42 hdisk40 hdisk38 hdisk37 o hdisk43 The source and target volume of each FlashCopy pair reside in the same ESS LSS 0000 Note The root userid must be used to execute all ESS and AIX commands and to install DB2 an
6. Scenario 27 Standby database scenario This scenario starts with the SAP R 3 system TS1 running on the Primary server On the Backup server TS1 is stopped and the DB2 filesystems for data and logs are unmounted This scenario assumes that the FlashCopy pairs and tasks are already defined on the ESS Copy Services Server Because the standby scenario requires logs from the Primary database to be applied to the Backup database configure the SAP DB2 userexit program to copy the log files to the Backup server Ship the archive logs to the Backup server so that the Backup database can apply these logs To do this 1 NFS mount the log directory of the Backup system TS1 on MACHB 2 In the configuration file init TS1 db6 in the directory usr sap TS1 SYS global set the value of the variable DB2DB6_STANDBY_DIR to the NFS mounted log directory of the target system For more details on how to configure the SAP DB2 administration tools see the SAP manual SAP Database Aaministration Guide IBM DB2 Universal Database for UNIX and Windows that is also available at http service sap com installguides 1 Issue the suspend command on the Primary database db2 connect to tsl db2 set write suspend for database 2 Flash the data pairs from the Primary server usr opt ibm2105cli rsExecuteTask sh v s ESSCSS tsldbdata Attention For this scenario do not copy or make available to the Backup server the db
7. online backup scenario on page 31 e Creating a split mirror copy of the SAP R 3 database that can be copied over the primary database Split mirror restore scenario on page 3424 Figure 1 provides the conceptual overview of the sample configuration Primary Backup Server Server ill e Snapshot for reporting Li u testing etc e Hot Standby 110 i e Offloading database 11 backups e Database restore A Lu SAP R 3 FlashCopy System TS1 change profiles FlashCopy IBM ESS F20 Figure 1 Conceptual overview As Figure 1 shows there are two AIX hosts one as the Primary Server the other as the Backup server Ten ESS logical volumes are attached to each system One logical volume is used for the SAP system software and configuration files the others for the database Two SAP R 3 with DB2 UDB and ESS Sample Configuration 12 volume groups are created on the Primary server for the SAP system and the database respectively DB2 Universal Database v7 2 for AIX is used DB2 UDB suspended 1 0 capabilities are available on all platforms supported by DB2 UDB An IBM ESS 2105 F20 is used The same scenarios also pertain to other ESS models supporting the same functionality as the ESS F20 such as the ESS Model 800 Silvertip The servers were attached to the ESS via SCSI adapters but alternatively fibre channel may
8. statements provided in this document should not be interpreted as such Trademarks ii Table of contents BET WRITE SUSPEND BET WRITE RESUME DB2INIDB OVERVIEW OF IBM 2105 ENTERPRISE STORAGE SERVER OVERVIEW OF COPY SERVICES OVERVIEW OF THE ESS COPY SERVICES WEB INTERFACE OVERVIEW OF ESS COMMAND LINE INTERFACE CLI ESS COPY SERVICES CLI COMMAND DESCRIPTION SUMMARY Table of contents iii Abstract SAP R 3 and its components have been the success of more than 19 000 installations in enterprises of every size in more than 106 countries worldwide The SAP R 3 system is an open integrated system that covers all business applications including accounting and controlling production and materials management quality management and plant maintenance sales and distribution human resources and project management The mySAP com e business platform is a suite of solutions and services that empower employees customers and business partners to collaborate successfully anywhere anytime IBM DB2 Universal Database UDB is the industry s first multimedia Web ready relational database management system strong enough to meet the demands of large corporations and flexible enough to serve medium sized and small e businesses DB2 Universal Database combines integrated power for business intelligence content management and e business with industry leading performance and reliability and is thus ideally
9. suited as the database system for SAP R 3 and mySAP com This coupled with the FlashCopy feature of the IBM Enterprise Storage Server enables high availability solutions like the creation of clone SAP R 3 systems standby databases and system backups with nearly no performance impact and zero downtime This document takes you through a sample configuration setup using SAP R 3 Release 4 6D with DB2 UDB Enterprise Edition EE V7 2 and IBM Enterprise Storage Server FlashCopy Abstract 1v About the authors Aslam Nomani has been working with the IBM Database Technology team in the Toronto Laboratory for five years For the past four years he has worked in the DB2 UDB System Verification Test department Aslam has worked extensively in testing DB2 UDB EE and DB2 UDB EEE in a high availability environment He is currently one of the team leads within the UDB test organization Enzo Cialini has been working with Database Technology at the IBM SWS Toronto Laboratory for ten years is certified in DB2 UDB Database Administration and DB2 UDB Database Application Development is an Advanced Technical Expert in DB2 for DRDA and an Advanced Technical Expert in DB2 for Clusters He is currently responsible for managing the DB2 UDB System Verification Test Department with a focus on High Availability and has been involved with DB2 in highly available environments for many years His experience ranges from implementing and supporting numerous insta
10. supported Overview of FlashCopy 5 Overview of FlashCopy Overview of the ESS Copy Services Web interface The ESS Copy Services Web interface is used to create and manage Copy Services tasks This Web interface consists of a number of HTML screens and Java applets and can be accessed from a standard Web browser A Copy Services task consists of e The IDs of the source and target disks involved e The operation to be performed Establish FlashCopy pair Withdraw FlashCopy pair Establish PPRC copy pair Suspend PPRC copy pair o Terminate PPRC copy pair e Several other options that is whether or not to perform background copy o ooo For example to create a task named fctask that establishes a FlashCopy relationship between two disks with the no copy option 1 Select the LSS in which the source and target disk reside 2 Left click the source disk right click the target disk and right click againto display the Options menu 3 Select Establish FlashCopy pair from the first menu and click Next 4 Select Do not perform background copy if checked from the second menu and click Next 5 Enter fctask as the task s name and a task description and click Save to store the task on the Copy Services server You can execute the task from the Tasks menu of the Copy Services Web interface or from any server on which the ESS Command Line interface is installed You can install the command line interface on any server atta
11. to take a backup you should create PSAPTEMP as a DMS tablespace With DB2 UDB V7 2 you cannot take backups of split mirror database copies unless all the tablespaces are DMS Overview of Standard SAP R 3 System Installation with DB2 UDB 10 Detailed discussions about the layout of a SAP R 3 system on an ESS are contained in the following white papers Sanjoy Das Siegfried Schmidt Jens Claussen BalaSanni Godavari Storage Management for SAP and DB2 UDB Split Mirror Backup Recovery with IBM at Enterprise Storage Server ESS http www storage ibm com hardsoft products sap smdb2 paf Siegfried Schmidt SAP R 3 Storage Management Split Mirror Backup Recovery on IBM s Enterprise Storage Server ESS at http www storage ibm com hardsoft products sap smsm200 pd Jens Claussen Database Layout for SAP Installations with DB2 UDB for Unix and Windows at http service sap com atg Overview of Standard SAP R 3 System Installation with DB2 UDB 11 Sample configuration of SAP R 3 with DB2 UDB and IBM ESS In this configuration we will work with a standard SAP R 3 installation and describe the following different scenarios that use the DB2 UDB split mirror functionality e Creating a clone SAP system Snapshot database scenario on na e Creating a standby SAP database Standby database scenario on page 28 e Creating a split mirror copy of the SAP R 3 database for backup and restore Split Mirror
12. 2 TS1 10g dir file system on the Primary server at this point 3 Wait for the FlashCopy task to finish 4 Issue the resume command from the same connection used in step 1 db2 set write resume for database 5 Mount the data filesystem on the Backup server mount db2 TS1 db2ts1 NODE0000 mount db2 TS1 sapdatal mount db2 TS1 sapdata2 mount db2 TS1 sapdata3 mount db2 TS1 sapdata4 n n n nount db2 TS1 sapdata5 nount db2 TS1 sapdata6 nount db2 TS1 sapdata7 ct ct ct ct ct ct ct o o O O O O Standby Database Scenario 28 10 11 12 13 14 Start the DB2 instance db2ts1 on the Backup server db2start Place the Backup database into a rollforward pending state and take it out of its suspended state db2inidb tsl as standby As DB2 log files are successfully getting archived to the archive directory on the Primary database make them available to the retrieve path for the Backup database Be careful not to roll forward through a log file on the Backup server that is only partially copied to the retrieve directory On the Backup database roll forward through the DB2 logs that have been archived from the Primary database The rollforward command gives you the options to roll forward to end of logs or to a point in time Rolling forward to a point in time can be useful if the intention is to keep the Backup database a constant amount of time behind the Primary database db2 rollfor
13. 7 2 or V7 1 Fixpack 3 at In addition see the DB2 Developer Domain article entitled Split Mirror Using Suspended 1 0 in DB2 DB2 UDB commands 2 Universal Database V7 wwwTb software 1bm com dmdd library techarticle 0204quazi 0204quazi html DB2 UDB commands Overview of IBM 2105 Enterprise Storage Server The IBM 2105 Enterprise Storage Server ESS provides superior storage sharing for Unix Windows NT Windows 20000 Novell Netware iSeries and zSeries servers With the ESS any combination of these heterogeneous platforms can be used Hosts are attached to the ESS via the following interfaces e Fibre Channel for Unix Windows NT and Windows 2000 e UItraSCSI for Unix Windows NT and Windows 2000 Novell Netware and e iSeries ESCON and FICON for zSeries The ESS provides the image of a set of logical disk devices to the attached servers The logical devices are configured to emulate disk device types that are compatible with the attached servers The logical devices access a logical volume that is implemented using multiple disk drives The ESS consists of the following components e Storage server the storage server is composed of two clusters that control and manage data transfer If one cluster fails the remaining cluster takes over the functions of the failing one e Host adapters each cluster has one or more host adapters that provide one or more host I O interfaces A host adapter can commun
14. Database Scenario 29 15 before the logic error occurred If the database needs to be recovered to the point when the Primary server failed then a rollforward to end of logs should be performed db2 rollforward database ts1 to end of logs and stop or db2 rollforward database ts1 to 2000 06 19 20 57 00 0000 and stop Start the SAP system log on as ts1adm user on the Backup server and issue the command startsap Standby Database Scenario 30 Split Mirror online backup scenario This scenario starts with the SAP R 3 system TS1 running on the Primary server The Backup server has TS1 stopped and DB2 file systems for data and logs unmounted Attention This scenario is currently not supported for databases that contain SMS tablespaces 1 NFS mount the log directory of the system where you want to restore the backup and configure the SAP DB2 userexit program so that it copies the log files to this directory in the configuration file init TS1 ab6 in the directory usr sap TS1 SYS global set the value of the variable DB2DB6_STANDBY_DIR to the NFS mounted log directory of the target system For more details on how to configure the SAP DB2 administration tools please refer to the SAP manual SAP Database Administration Guide IBM DB2 Universal Database for UNIX and Windows that is available at http service sap com installguides 2 Issue the suspend command on the Primary database db2 connect to tsl db2 set
15. Using IBM TotalStorage Enterprise Storage Server ESS with IBM DB2 UDB Enterprise Edition V7 2 and SAP R 3 October 2002 Brigitte Bl ser IBM Germany B blingen Laboratory Enzo Cialini IBM Toronto Laboratory Aslam Nomani IBM Toronto Laboratory David Davis IBM Storage Systems Group O Copyright International Business Machines Corporation 2002 All rights reserved Trademarks The following terms are trademarks or registered trademarks of International Business Machines Corporation in the United States other countries or both AIX DB2 DB2 Universal Database Enterprise Storage Server ESS ESCON FlashCopy IBM Series zSeries The following terms are trademarks SAP AG in Germany in the United States other countries or both SAP mySAP com R 3 Other products or service names may be trademarks or registered trademarks of their respective owners Unix and Unix based trademarks and logos are trademarks or registered trademarks of The Open Group Windows and Windows based trademarks and logos are trademarks or registered trademarks of Microsoft Corp The furnishing of this document does not imply giving license to any IBM patents References in this document to IBM products Programs or Services do not imply that IBM intends to make these available in all countries in which IBM operates The information contained in this publication does not include any product warranties and any
16. a7 A yes p rw crfs v jfs d dbloglv m db2 TS1 log dir A yes p rw Change the size of the file system it is changed to 7GB in this example chfs a size 14000000 usr sap chfs a size 14000000 db2 TS1 sapdatal chfs a size 14000000 db2 TS1 sapdata2 chfs a size 14000000 db2 TS1 sapdata3 chfs a size 14000000 db2 TS1 sapdata4 chfs a size 14000000 db2 TS1 sapdata5 Configuring a Two Host System 22 chfs a size 1 chfs a size 1 chfs a size 1 chfs a size 1 1000000 db2 TS1 sapdata6 1000000 db2 TS1 sapdata7 1000000 db2 TS1 log_dir 1000000 db2 TS1 db2ts1 NODE0000 ha A DB gt Mount the file systems un un un un un un un un un 0000000000 usr sap db2 TS1 db2ts1 NODE0000 db2 TS1 sapdatal db2 TS1 sapdata2 db2 TS1 sapdata3 db2 TS1 sapdata4 db2 TS1 sapdata5 db2 TS1 sapdata6 db2 TS1 sapdata7 un CCE eh CE CR her db2 TS1 log_dir Change ownership of the file systems to the SAP administrative user and DB2 instance owner respectively users ts1adm in group sapsys and user db2ts1 and group dbtsiadm in this example chown tsladm sapsys usr sap nown nown nown own nown nown nown nown Qu Quo quo oq J 6 db2ts1 dbtsladm db2 TS1 sapdatal db2ts1 dbtsladm db2 TS1 sapdata2 db2ts1 dbtsladm db2 TS1 sapdata3 db2ts1 dbtsladm db2 TS1 sapdata4 db2ts1 dbtsladm db2 TS1 sapda
17. abase Provide a standby database that can be accessed as a disaster recovery strategy if the primary database is not available All logs from the primary database will be applied to the secondary database so that the secondary database represents a transactionally consistent version of the primary database at the time of the failure Provide the ability to offload backups from the primary database A DB2 backup can be performed on the secondary database system The DB2 backup can then be restored on either the primary system or on another system Then the database can be rolled forward to bring the database to a particular point in time or until the end of the logs are reached Provide the ability for a quick database restore The mirror pair can be resynced so that the primary copy is restored to the initial data at the time of the split Then the primary database can be rolled forward to bring the database to a particular point in time or until the end of the logs are reached DB2 UDB suspended I O overview 1 DB2 UDB commands We use the following commands set write suspend The suspend command db2 set write suspend for database suspends all write operations to the DB2 UDB database i e to tablespaces and log files Read operations are not suspended and are thus allowed to continue Applications can continue to process insert update and delete operations utilizing the DB2 bufferpools A database connection is required for
18. abase instance installed on a single host We do not consider the installation of dialog instances on additional systems We will further assume that the transport host is installed on the same host as the central instance The base directories required for the SAP R 3 central instance are usr sap for the general SAP R 3 software and usr sap trans which contains SAP R 3 software for the transport of objects between SAP R 3 systems The SAP R 3 software and configuration files are installed in the directory usr sap lt SID gt The directory is owned by the user lt sid gt adm which belongs to the group sapsys For each R 3 system there is one DB2 instance db2 lt sid gt that contains the SAP R 3 database lt SID gt and an administration database ADM lt SID gt for managing backup images and log files The db2 lt sid gt directory is owned by the user db2 lt sid gt which belongs to the group db lt sid gt adm db lt sid gt adm is the SYSADM GROUP of the DB2 instance This results in the following directory structure SAP software usr sap lt SID gt trans DB2 instance db2 lt SID gt db2 lt sid gt NODE0000 log_dir log_archive log_retrieve sapdatal sapdata2 sapdata3 sapdata4 sapdata5 sapdata6 sapdatat sqllib By default all the tablespaces are database managed storage DMS except for the temporary tablespace PSAPTEMP which is system managed storage SMS If you want to use the split mirror copy of the database
19. ation of the IBM Enterprise Storage Server provides an ideal environment for running an SAP R 3 system Split Mirror Restore Scenario 35
20. be used Installing Advanced Copy Services An IBM representative should install Copy Services on the ESS 2105 F20 Copy Services is a separately sold feature of the ESS It includes FlashCopy for the Open Systems environment Installing the Command Line Interface on AIX Install the ESS Command Line Interface on the AlX server from which you want to execute the FlashCopy tasks Alternatively you can also execute the FlashCopy tasks from the ESS Copy Services Web Interface Install the Copy Services Command Line Interface software It requires the IBM 2105 Runtime environment for AIX as a prerequisite The installation fileset of the Command Line Interface is named ibm2105cli rte The destination of the fileset is usr opt ibm2105cli The installation fileset of the IBM 2105 Runtime environment for AIX is ibm2105 rte The destination of the fileset is usr opt iom2105 Creating and assigning ESS logical volumes 1 Use the StorWatch ESS Specialist Web Interface to define logical volumes and assign them to the Primary and the Backup server a Select Storage Allocation from the StorWatch ESS Specialist menu b Select Open Systems Storage gt Modify Volume Assignments gt Add Volumes c Select the server the SCSI adapter to which the logical volume s should be attached and the disk group on which the logical volumes should be created and click Next d Select Raid 5 as storage type specify the size and number of logical volumes a
21. ched to the ESS via TCP IP A basic FlashCopy task can only contain disk pairs from one LSS You can combine several basic FlashCopy tasks into one group task to establish or withdraw FlashCopy pairs in several LSSs Please note that the source and target disks of a FlashCopy pair always have to reside in the same LSS Overview of ESS Copy Services Web Interface 7 Overview of ESS Command Line Interface CLI The ESS Command Line Interface consists of a number of scripts to communicate with the ESS Copy Services server The Command Line Interface is Java based and therefore requires the Java JDK version 1 1 8 to be installed on each host system from which you want to issue the commands The CLI code level must be at the same release level as the microcode that is installed in the ESS clusters The CLI can be installed on any host system that is connected to the ESS that is defined as the primary Copy Services server via a local area network It is not required that the host system is attached to the ESS storage In the ESS Copy Services Web Interface you can configure that the execution of Copy Services server commands is password protected If you enable password protection you have to provide a user ID and password with each command invocation Overview of ESS Command Line Interface CLI 8 ESS Copy Services CLl command description rsExecuteTask Executes one or more predefined Copy Services Server tasks and waits for the tasks to
22. d create the DB2 instance The remainder of the DB2 commands are executed from the ID db2ts1 which is the DB2 instance owning ID 1 Create the logical volumes in each LSS and assign them to the Primary Server and the Backup Server via the Web interface of the StorWatch Enterprise Storage Specialist From each AIX server run cfgmgr to define SCSI paths to the ESS Create a FlashCopy task for the SAP system via the ESS Copy Services Web interface a Create the task ts1sap to flash the disk on which the SAP software is installed b If you defined the task ts1sap with the no copy option you must also define another task called ts1sapwd to withdraw the FlashCopy pair for the SAP software If you did not specify no copy do not create ts1sapwd We will need a number of FlashCopy tasks for the database file systems to support the different scenarios a Create the tasks tsidb_10 to tsidb 17 to flash the logical volumes containing the database data and log files in each LSS If you create the tasks with the no copy option you must create appropriate tasks tsidb_10_wdto tsidb_17_wd to withdraw the FlashCopy pairs b Group the tasks as follows Group tsidb_10 to ts1db_17 into task ts1db Group tsidb_10_wd to tstdb 17 wd into task ts1dbwd With these tasks FlashCopy pairs for the data and log file systems of the database can be established and withdrawn For the Standby Database Scenario we need a FlashCopy task that only
23. db2 TS1 sapdata3 umount db2 TS1 sapdata4 umount db2 TS1 sapdata5 umount db2 TS1 sapdata6 umount db2 TS1 sapdata7 umount db2 TS1 log_dir GAGE Gh lGh gh Gr ct ook ich 000000000 Withdraw the FlashCopy pairs for the database and log files usr opt ibm2105cli rsExecuteTask sh v s ESSCSS tsldbwd and wait for the FlashCopy task to finish Restore the DB2 backup image taken on the Backup serverto any DB2 server including the Primary server using the DB2 restore command 1 Stop the SAP system on the Primary server by logging on as user ts1adm and issuing the following command which also stops the DB2 instance stopsap Restore the DB2 backup to the desired machine db2 restore database tsl from backupfs Make sure that logs from the Primary server are available to the machine where the database restore was performed thus allowing a rollforward through the logs After the restore is successful roll forward through the DB2 logs The rollforward command allows the option to roll forward to end of logs or to roll forward to a point in time Ensure all logs that are required from the Primary server are available to the new system db2 rollforward database tsl to end of logs and stop or db2 rollforward database tsl to 2000 06 19 19 56 00 0000 and stop Split Mirror Online Backup Scenario 32 5 Start the SAP system TS1 by logging on as ts1adm user and issuing the followin
24. ew of Copy Services Copy Services is a separately priced feature of the ESS which provides powerful functions for replication of mission critical data For the Open Systems environment Copy Services offer point in time replication with FlashCopy and dynamic synchronous mirroring to a remote ESS with Peer to Peer Remote Copy PPRC The examples described in this paper use FlashCopy FlashCopy creates instant point in time copies of logical volumes LVs for purposes such as data backup or data duplication The copy is called time zero TO copy It is a binary copy that looks exactly the same as the source volume at the time the copy was made When executing FlashCopy the ESS establishes the FlashCopy pairs and creates control bitmaps This only takes a few seconds Both source and target volumes can be accessed immediately after the FlashCopy pairs have been established and the bitmaps created Background tasks continue copying the data from the source to the target volumes The FlashCopy relationship between source and target volume ends when the physical background copy tasks completed Source and target volume can be accessed and modified independently FlashCopy can also be used with the no copy option This suppresses copying of the complete source volume Only the data that changes on the source volume is copied to the target volume before the changes are made on the source volume The FlashCopy relationship between source and target vol
25. g command startsap Split Mirror Online Backup Scenario 33 Split mirror restore scenario This scenario starts with the SAP R 3 system TS1 running on the Primary server The Backup server has TS1 stopped and DB2 file system for data and logs unmounted 1 Edit the userexit program and place it in the appropriate directory on the Primary server so DB2 knows where archived logs are located The user exit program will archive the logs Issue the suspend command on the Primary database db2 connect to tsl db2 set write suspend for database Execute the FlashCopy task tsidbdata from the Primary server as root user usr opt ibm2105cli rsExecuteTask sh v s ESSCSS tsldbdatafc Wait for rsExecuteTask to return Issue the resume command from the same connection in Step 2 db2 set write resume for database If the Primary database gets corrupted due to a database application error or some other error that prevents the database from being restarted another FlashCopy task that copies the former target volumes to the former source volumes can then be executed At this point DB2 should no longer be running on the Primary server Unmount the db2 TS1 data file systems on the Primary server umount db2 TS1 db2ts1 NODE0000 unt db2 TS1 sapdatal unt db2 TS1 sapdata2 unt db2 TS1 sapdata3 unt db2 TS1 sapdata4 unt db2 TS1 sapdata5 unt db2 TS1 sapdata6 unt db2 TS1 sapdata7 00000000
26. handles the database data filesystems without the log filesystem We group the tasks ts1db_10 to tstdb_16 into the group task ts1dbdata and the tasks tstdb_10_wd to tsidb_16_wd into the group task tsidbdatawd We will also need a FlashCopy task for flashing the log filesystem and for withdrawing the FlashCopy pair Configuring a Two Host System 17 For the Split Mirror Restore Scenario we need FlashCopy tasks for the database data filesystems only without the no copy option We also need FlashCopy tasks for establishing reverse FlashCopy pairs for the database data filesystems Although these could be defined with the no copy option this is not recommended We create two group tasks ts1dbdatafc and tsidbdatarevic The following table lists the FlashCopy tasks that we created 5 Onthe Primary server create volume groups logical volumes and file systems to be used by SAP and DB2 Then change the size of the file systems mount the file systems and change ownership of the file systems to the SAP administrator user and the DB2 instance owner respectively Below is a list of file systems that will be used for storing the data for the examples used throughout this paper The file systems for DB2 data are contained in db2 TS1 sapdatal to db2 TS1 sapdata7 The file system for DB2 s active log files is contained in db2 TS1 log_dir The file system for databases and the database directory is contained in db2 TS1 db2ts1 NODE0000
27. icate with either cluster complex e Device adapters each cluster has one or more device adapters that provide one or more storage device interfaces Disk drives are attached to a pair of device adapters one in each cluster so that the drives are accessible from either cluster e Cluster complex the cluster complex provides the management functions for the ESS It consists of cluster processors cluster memory cache nonvolatile storage and related logic e The disk drives provide the primary nonvolatile storage medium for any host data stored within the ESS storage devices They are grouped into ranks and are managed by the clusters Internally the ESS is divided into Logical Subsystems LSSs An LSS is a logical structure that is used for configuration of the ESS An ESS can have up to 16 LSSs defined for Open Systems storage In one LSS up to 256 logical volumes can be defined Storage capacity is partitioned among the attached servers using the flexible Web based StorWatch Enterprise Storage Specialist management tool With its Web interface you can create assign and unassign logical volumes to the hosts attached to the ESS For details about the ESS ESS Copy Services and the Web and command line interfaces please refer to the following Redbooks available at e SG245757 Implementing ESS Copy Services on UNIX and Windows NT 2000 e SG245465 IBM Enterprise Storage Server Overview of IBM 2105 Enterprise Storage Server 4 Overvi
28. ifies the hostname of the Copy Services Server Wait for rsExecuteTask to return 3 Issue the resume command from the same connection in step 1 db2 set write resume for database 4 From the Backup server mount the file systems mount db2 TS1 db2ts1 NODE0000 unt db2 TS1 sapdatal unt db2 TS1 sapdata2 unt db2 TS1 sapdata3 unt db2 TS1 sapdata4 unt db2 TS1 sapdata5 unt db2 TS1 sapdata6 unt db2 TS1 sapdata7 unt db2 TS1 log dir 20000000 Sra 5 Start the DB2 instance db2ts1 on the Backup server db2start 6 The following command performs crash recovery on the database and takes it out of a suspended state db2inidb tsl as snapshot The database on the Backup server is now in a transactionally consistent state at the time the suspend command was issued against the Primary database 7 Start the SAP system TS1 by logging on as user ts1adm on the Backup server and issuing the following command startsap 8 To reconfigure the transport system for the new host log on to the SAP system and execute transaction STMS If a new snapshot image is desired stop the SAP system TS1 on the Backup server and unmount the db2 TS1 file systems Then withdraw the existing FlashCopy pairs by executing the task ts1dbwd if they had been flashed using the no copy option Then re establish the FlashCopy pairs and execute the above steps again Snapshot Database Scenario 26 Snapshot Database
29. issuing the suspend command It is recommended that you maintain the current session for executing the subsequent resume command set write resume The resume command db2 set write resume for database resumes all write operations to the suspended DB2 UDB database A database connection is required for issuing the resume command db2inidb The db2inidb command db2inidb lt db_alias gt as lt snapshot standby mirror gt is required to initialize the copy of the suspended database You do not require a database connection prior to executing this command It can be used in the following three cases e snapshot can be applied to the secondary copy putting it into a transactionally consistent state e standby can be applied to the secondary copy putting it into a rollforward pending state DB2 logs from the primary database can then be applied to the secondary database e mirror can be applied to the primary copy after it has been restored from the secondary copy The primary database will be placed into a rollforward pending state and then DB2 logs can be applied to the primary database restart write resume The restart write resume command db2 restart db lt db_alias gt write resume can be utilized to resume write operations on a suspended database that experienced an abnormal termination For further information regarding DB2 UDB s suspended 1 O functionality see the DB2 UDB documentation and Release Notes provided with V
30. llations to consulting Brigitte Bl ser has been working for IBM for 17 years She has been engaged in several development projects using DB2 UDB and SAP R 3 She is certified in DB2 UDB Database Administration and DB2 UDB Database Application Development She is currently working in the SAP DB2 Development Porting department of the IBM Germany B blingen Lab and responsible for supporting the SAP IT department in migrating internal SAP systems to DB2 UDB This includes the definition and implementation of High Availability solutions David Davis is a Product Professional with SSG Software Development in San Jose California He has 1 year of experience in application and database integration with storage products Previously he worked for 6 years in IBM s Professional Services as a consultant in database and application development engagements About the authors V DB2 UDB suspended l O overview DB2 UDB v7 2 has implemented suspended I O technology which provides the capability to use split mirroring technology while DB2 is online Suspended I O supports continuous system availability by providing a full implementation for splitting a mirror pair without shutting down the database The split copy of the database can be used to do such things as Provide a transactionally consistent snapshot of the database at the current point in time This database can be used to offload user queries that don t need the most current version of the dat
31. lowing command mkvg f y dbvg s 64 hdisk9 hdisk11 hdisk21 hdisk26 hdisk28 hdisk29 hdisk33 hdisk34 hdisk41 Create logical volumes The following procedure creates two logical group names saplv and data1lv smit lv gt Add a Logical Volume gt VOLUME GROUP name sapvg Configuring a Two Host System 19 Add a Logical Type or select values in entry fields Press Enter AFTER making all desired changes Logical volume NAME VOLUME GROUP name Number of LOGICAL PARTITIONS PHYSICAL VOLUME names Logical volume TYPE POSITION on physical volume RANGE of physical volumes MAXIMUM NUMBER of PHYSICAL VOLUMES to use for allocation Number of COPIES of each logical partition Mirror Write Consistency Allocate each logical partition copy on a SEPARATE physical volume RELOCATE the logical volume during reorganization Logical volume LABEL MAXIMUM NUMBER of LOGICAL PARTITIONS Enable BAD BLOCK relocation SCHEDULING POLICY for reading writing logical partition copies Enable WRITE VERIFY File containing ALLOCATION MAP T s E Stripe Size Alternatively issue the following command mklv y saplv sapvg 60 smit lv Volume mn Fields an middle minimum 1 yes yes yes 512 yes parallel no Not Striped gt Add a Logical Volume gt VOLUME GROUP name dbvg Configuring a Two Host System 20 Add a Logical Volume Type or select values in entry fields
32. nce owner is identical across both machines The current example will use db2ts1 as the instance owner Since there are two separate copies of the instance directory ensure that you update database manager configuration parameters and DB2 profile variables on both instances if required After installation the SAP system on the Primary server will be started automatically Configuring a Two Host System 24 11 On the Backup server from the db2inst1 instance catalog the database TS1 even though the file systems that contain the database TS1 does not currently exist on the Backup server db2 catalog db TS1 on db2 TS1 The base configuration is now done and the following sections will provide examples on how ESS FlashCopy technology and DB2 UDB suspended I O technology can be used together Configuring a Two Host System 25 Snapshot database scenario This scenario starts with SAP R 3 system TS1 running on the Primary server and clients using the Primary database The Backup server has TS1 and DB2 stopped and DB2 file systems for data and logs unmounted 1 From the Primary Server issue the suspend command on the Primary database db2 connect to tsl db2 set write suspend for database 2 Execute the FlashCopy task ts1db for flashing the data and log file systems from the Primary server as root user usr opt ibm2105cli rsExecuteTask sh v s ESSCSS tsldb The v option indicates verbose mode the s parameter spec
33. nd click Perform Configuration Update e Repeat these steps until you have created and assigned all logical volumes that are required Make sure that for each source disk you create a target disk of the same size or bigger in the same ESS LSS 2 Oneach AIX server run cfgmgr to define SCSI paths to the ESS The ESS logical volumes will be visible as hdisks on the Primary and Backup servers Use the following AIX command to list the ESS logical volumes assigned to a server SAP R 3 with DB2 UDB and ESS Sample Configuration 13 lsdev C grep 2105 3 Use the ESS Command Line Interface command rsList2105s to display the mapping of host physical volume name to ESS volume serial number for all disks assigned to the host system cd usr opt ibm2105cli rsList2105s sh 4 Determine the SCSI paths and disks to be used for the SAP system the DB2 database and the DB2 logs 5 Document the corresponding Idev s logical devices gt gt to be used for AIX logical volumes SAP R 3 with DB2 UDB and ESS Sample Configuration 14 Configuring a system with two hosts Overview 1 Install the ESS CLI on the Primary Server 2 Assign ESS disks to both servers 3 Install DB2 for AIX on both servers 4 Install a standard SAP R 3 system on the Primary Server Figure 2 shows the configuration we used for the FlashCopy examples LI Primary Backup il Server Server l MACHA MACHB SAP R 3 TS1 Copy Services Server ESSCSS
34. ta5 db2tsl dbtsladm db2 TS1 sapdata6 db2tsl dbtsladm db2 TS1 sapdata7 db2tsl dbtsladm db2 TS1 log_dir Install DB2 on both the Primary and Backup server if this is not already done Further information on installing DB2 can be found in the DB2 UDB documentation Install the SAP R 3 system as Central Instance database server and SAP application server on the same system on the Primary server from the SAP CDs as described in the SAP installation guide with the R3Setup program Name the SAP system TS1 and use 00 as system number Before running R3Setup modify the file DBSIZE TPL in the installation directory as follows replace PSAPTEMP 0 0 32 4 Z_SAPDATAPATH SAPDATAT with PSAPTEMP 1800 1 8 4 Z_SAPDATAPATH SAPDATA7 This change will cause the temporary tablespace PSAPTEMP to be created as a DMS tablespace with one container in db2 TS1 sapdata7 By default an SMS tablespace is created The R3Setup program will create the DB2 instance db2ts1 and the database TS1 It will also update the database configuration to set the log path to Configuring a Two Host System 23 8 9 10 db2 TS1 log_dir Loading the data into the database may last several hours For more details about installing an SAP R 3 system please refer to the SAP R 3 Installation Guide Flash the SAP software to the target disk and system a Create the group dbts1adm and the user tsiadm on the target system with the same
35. ume exists until it is withdrawn manually When the FlashCopy relationship ends the copy is no longer available for use Here are the restrictions for FlashCopy e A FlashCopy relationship can only be established between disk volumes Source and target volumes have to reside within the same Open System s Logical Subsystem LSS e The target disk must have the same size as the source volume or must be bigger e Both source and target volumes can only be involved in one FlashCopy relationship at a time e The target can only be used on the same operating system Copy Services run inside the ESS FlashCopy can be used to quickly create copies of production data for the purpose of taking backups creating test systems or creating database copies for data mining purposes or data warehouses FlashCopy has no significant impact on the performance nor does it require downtime of the production system Using PPRC one ESS has to be defined as the Primary Copy Services Server This ESS holds all Copy Services related information i e the volumes and their current state Optionally a second ESS could be defined to be the Backup Copy Services Server On each ESS that is intended to use Copy Services there is a Copy Services client running which communicates with the server Access to Copy Services is provided through an Internet browser This allows for controlling the ESS copy functionality over the network from any platform for which the browser is
36. userid and groupid as on the source system b Copy the files from the tstadm home directory default home t s 1 adm to the tstadm home directory on the target system Alternatively you can also place the home directory of the tstadm user on the ESS disk used for the SAP system and create a link c Make the following changes to the files in the home directory on the target system a Change the names of the files doenv_MACHA csh and sapenv_MACHA csh to dbenv_MACHB csh and sapenv_MACHB csh respectively a Change the names of the scripts used to start and stop the SAP system change startsap_MACHA_00 and stopsap MACHA 00 to startsap_MACHB_00 and stopsap_MACHB_00 respectively d As root user execute the ts1sap FlashCopy task usr opt ibm2105cli rsExecuteTask sh v s ESSCSS tslsap e Mount the file system usr sap on the target system mount usr sap f Modify the SAP system profiles on the target system in the directory usr sap TS1 SYS profile as follows e Change the names of the profiles START DVEBMGSO00 MACHA and TS1_DVEBMGS00_MACHA to START DVEBMGSO00 MACHB and TS1 DVEBMGSOO MACHB respectively e Edit the profiles DEFAULT PFL START DVEBMGSO00 MACHB and TS1_DVEBMGS00_MACHB and change all occurrences of MACHA to MACHB Create an identical instance db2ts1 on the Backup server The HOME file system is not part of a pair and may reside on an internal disk Ensure the UID GID of the insta
37. ward database tsl to end of logs or db2 rollforward database tsl to 2000 06 19 19 56 00 0000 Note The retrieved log files are copied to db2 TS1 log_dir by DB2 during the rollforward which is the current mount point for the log directory Ensure that the instance owner has write access to this directory and that the directory is large enough When the log logical volume is copied and db2 TS1 log_dir is mounted the contents of the db2 TS1 log_dir mount point will no longer be visible This does not cause a problem because any log files that may have been in this directory can still be retrieved from the retrieve path Continue with iterations of the previous ro11 forward commands until the Primary database fails a database application logic error occurs or until use of the Backup database is desired If you do not need to roll forward through the most current logs from the Primary system then proceed to step 16 At this point ensure all log files that have been archived on the Primary server are available to the Backup server Copy the log pair from the Primary server usr opt ibm2105cli rsExecuteTask sh v s ESSCSS tsldblog and wait for FlashCopy task to finish Mount the log filesystem on the Backup server mount db2 TS1 1log dir Issue a rollforward stop command on the Backup database If a database application logic error occurred the user must rollforward to a point in time Standby
38. write suspend for database lu 3 Execute the FlashCopy task ts1db from the Primary server as root user usr opt ibm2105cli rsExecuteTask sh v s ESSCSS tsldb Wait for rsExecuteTask to return Note If you are at DB2 UDB V7 FP4 and above you do not have to copy the logs for this scenario 4 Issue the resume command from the same connection as used in Step 2 db2 set write resume for database 5 Mount the data and log filesystems on the Backup server mount db2 TS1 db2ts1 NODE0000 mount db2 TS1 sapdatal mount db2 TS1 sapdata2 mount db2 TS1 sapdata3 mount db2 TS1 sapdata4 mount db2 TS1 sapdata5 mount db2 TS1 sapdata6 mount db2 TS1 sapdata7 mount db2 TS1 log_dir Note If you are on DB2 UDB V7 FP4 and above you do not need to mount the db2 TS1 log_dir file system 6 Start the DB2 instance on the Backup server db2start Split Mirror Online Backup Scenario 31 10 11 The following command places the Backup database into a rollforward pending state and take it out of a suspended state db2inidb tsl as standby Perform a DB2 backup on the Backup server using the supported backup system db2 backup database tsl to backupfs Stop the DB2 instance on the Backup server db2stop Unmount the db2 T581 file systems on the Backup server umount db2 TS1 db2ts1 NODE0000 umount db2 TS1 sapdatal umount db2 TS1 sapdata2 umount
39. y fields Press Enter AFTER making all desired changes LOGICAL VOLUME name MOUNT POINT Mount AUTOMATICALLY at system restart PERMISSIONS Mount OPTIONS Start Disk Accounting no Number of bytes per inode 4096 Allocation Group Size MBytes 64 Alternatively issue the following command crfs v jfs d saplv m usr sap A yes p rw smit fs gt Add Change Show Delete File Systems gt Journaled File Systems gt Add a Journaled File System on a Previously Defined Logical Volume gt Add a Standard Journaled File System Add a Large File Enabled Journaled File System Type or select values in entry fields Press Enter AFTER making all desired changes Entry Fields datally db2 TS1 sapdatatyl LOGICAL VOLUME name MOUNT POINT Mount AUTOMATICALLY at system restart MES PERMISSIONS read write Mount OPTIONS Start Disk Accounting no Number of bytes per inode 4096 B4 PI Allocation Group Size MBytes Alternatively issue the following commands crfs v jfs d dblv m db2 TS1 db2ts1 NODE0000 A yes p rw crfs v jfs d datallv m db2 TS1 sapdatal A yes p rw crfs v jfs d data21v m db2 TS1 sapdata2 A yes p rw crfs v jfs d data3lv m db2 TS1 sapdata3 A yes p rw crfs v jfs d data4lv m db2 TS1 sapdata4 A yes p rw crfs v jfs d data5lv m db2 TS1 sapdata5 A yes p rw crfs v jfs d data6lv m db2 TS1 sapdata6 A yes p rw crfs v jfs d data7lv m db2 TS1 sapdat
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