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System for storing and managing plural logical volumes in each of

1. ICAT CATEGORY IPVO PHYSICAL VOLUME ONLY i PHYSICAL PARTITIONED VOLID VOLUME ID EXTERNAL VOLSER VOLUME SERIAL NUMBER INTERNAL U S Patent Aug 13 1996 Sheet 5 of 11 5 546 557 92 MANUALLY SELECT PHYSICAL VOLUMES THAT ARE TO BE PARTITIONED PVP S AND PVO S FIG 8 MANUALLY SPECIFY RANGE OF SIZES FOR LOGICAL OR VIRTUAL VOLUMES TO BE STORED IN THE SELECTED PHYSICAL VOLUMES MANUALLY IDENTIFY A RANGE OF VOLSER S FOR LOGICAL VOLUMES 9 5 96 MANUALLY DEFINE HEADER STANDARD FIELDS OF LOGICAL VOLUMES LABEL 97 ASSIGN ALL PVP S AND LV S TO THE INSERT CATEGORY 10 NO LIBRARY 1 0 YES 10 SET STACK CATEGORY FOR PVP 108 IDENTIFY PVP S amp PVO S 102 EXIT U S Patent Aug 13 1996 Sheet 6 of 11 5 546 557 PHYSICAL ONLY 0 10K 1 PVO 110 PVO 111 PARTITIONED VOLUMES FIG 9 10K 100K 1 VOLUME RANGE FIG 11 150 152 153 ASSIGN TO SCRATCH VOLSER S PRIORITY 155 156 157 158 DEVICE VOLSER S TARGET MIGRATE ADDRESS VOLID S LOCATION S 160 161 163 164 165 PHYSICAL DEVICE PARTITION VALUE BLOCK NUMBER OTHER PARAMETERS 172 170 CHANGE DEVICE EC OTHER SEGMENT ADDRESS DRE FIELDS 180 181 171 182 U S Patent Aug 13 1996 Sheet 7 of 11 5 546 557 120 REQUEST HOST PROCESSOR TO CREATE DATA STORAGE SPACE FOR A DATA SET FIG 10 12
2. mation to the attached host processor a plurality of host processor addressable media drives in said apparatus each said media drive for removably mounting for reading and writing to and from a physi cal volume having a record medium a plurality of said physical volumes in said apparatus each of said physical volumes for storing data therein in one or more host processor addressable logical data storage volumes volume moving means for inserting and removing said physical volumes into and from said media drives volume manager means connected to the attachment means for receiving mount commands from the attached host processor said mount commands includ ing an address of one of said media drives and a volume serial number of a mount command addressed one of said host processor addressable logical data storage volume to be mounted on said addressed media drive peripheral controller means having data flow means con nected to the attachment means and to the media drives for processing digital signals between said attachment means and said media drives volume map means connected to the volume manager means for storing identifications of said volume serial 3 20 25 35 40 45 50 60 65 28 numbers and indications of which of said physical volumes contain said host processor addressable logi cal data storage volumes respectively as a volume mapping of said host processor addressable logical data storage
3. said volume increasing means having means for accessing said data base means for determining the length of segments in the partition in which said addressed host processor addressable logical data storage vol ume resides and said volume increasing means responding to the accessing means for creating said predetermined partition using segments having a greater longitudinal lengths than the determined longitudinal lengths 20 In the apparatus set forth in claim 17 further includ ing in combination logical volume increasing means connected to said moni toring means for responding to said approach indication to abort said data appending for assigning a new logical volume to receive said data to be appended 21 In the apparatus set forth in claim 15 further includ ing in combination eject means in the volume manager means for indicating that given ones of said physical volumes are ejectable from the apparatus as respective identified ejectable physical volumes media storage means connected to said volume moving means for yielding and receiving said physical volumes for transport to and from the respective media drives said media storage means having an IO station con nected to the volume moving means for yielding and receiving certain ones of said physical volumes to and from the media storage means and having a manual input and manual output port said peripheral controller means having migrate initiating means connected to
4. A metbod of operating a peripheral data storage sub system programmed control means in the peripheral data storage sub system for controlling its operation attach ment means connected to the control means for attaching the sub system to a host processor a plurality of addressable media devices for removably receiving physical volumes of media means connected to the control means and to the media devices for mounting and demounting said physical volumes of media said media devices being connected to the attachment means for exchanging data signals therewith the method including steps establishing a plurality of volume serial numbers establishing a listing in said control means containing indications of a first set having a plurality of first ones of said volume serial numbers that are to be used only for identifying host processor addressable logical data Storage volumes establishing a second set of second ones of said volume serial numbers that are to be used only to identify stack ones of said physical volumes in which said host processor addressable logical data storage volumes can reside initializing predetermined ones of said host processor addressable logical data storage volumes including first allocating a predetermined partition of predetermined ones of said physical volumes for respective ones of said host processor addressable logical data storage volumes and establishing addressability of said host processor addressa
5. actuate PVM 57 to adjust the location information in a manner for quickly and precisely locate the command identified logical block PVM 57 responds by locating the VOLSER entry for the mounted LV PVM 57 reads the location information for the mounted LV for comparing same with the information received with the Locate Block JD command As one example assume that the last access to the addressed LV involving a Read Block ID command occurred when the addressed LV resided in a PVP in a half wrap in which the forward direction was indicated by 311 forward is from the free tape end toward the hub end and the LV was close to the free end Next assume that the LV was moved to a second PVP in which the LV was inserted to reside in a half wrap having a forward direction indicated by arrow 313 forward is from the hub end toward the free end and that the LV is near the hub end In all instances each LV is physically referenced to BOT such that if any LV is migrated to a PVO the PRV s remain correct That is the PRV s of each LV are relative to the PRV of the partition in which such LV resides PVM 57 then sends the adjusted values to PSC 52 for enabling PSC 52 to effect the high speed searching to the desired block id PSC 52 has a table not shown of segment sizes for the respective segment numbers or per range of segment numbers PSC 52 in step 234 converts the PVM 57 supplied segment numbers into a number of segments to be traversed from the
6. created established data storage volumes are logical or vir tual volumes hereinafter termed LV s As later detailed the peripheral data storage subsystem is initialized with a range of VOLSER s for facilitating orderly generation of LV s 10 30 35 40 45 50 55 60 65 10 The illustrated embodiment of this invention employs magnetic tape physical data storage volumes PVPs in which the LV s are created established In the host processor accessing or mounting such LV s the procedures are inde pendent of whether or not the VOLSER has been created established That is the peripheral data storage subsystem responds to a host processor request to mount a data storage volume herein an LV to create an LV having a VOLSER indicated in a host processor issued mount command FIG 3 illustrates a prior art magnetic tape format Mag netic tape 20 has a so called system area 21 at a free or leader end of magnetic tape 20 The beginning of the tape volume BOV is indicated by a format identification FID 22 FID 22 is typically a non data pattern that inter alia indicates recording density number of tracks etc of the prior art magnetic tape Boundary 23 of FID 22 marks the logical beginning of volume LBOV Area 24 of magnetic tape 20 contains the recorded data arranged in physical blocks of data Logical end of volume LEOV indicates a logical end of the storage portion of area 24 LEOV can be indicated by a mark on ma
7. identified VOLID field of entry 68 then comparing the sum with either a default value all PVPs have identical data storage capacities or the data storage capacity indicated in VOLID field of entry 68 as set forth above An alternate method of summing is to subtract the starting PRV entry 68 value from the ending PRV entry 69 value to ascertain the number of tape segments occupied by the existing LVs in the PVP being examined On the other hand the PVP may have only fixed sized partitions In that case there either is or is not an unassociated partition for receiving the LV In any event the number of unallocated segments of the PVP is determined Any PVP mounted on the selected tape drive is always considered first Such selection is a fastest procedure for establishing an LV in a PVP as it eliminates mounting a PVP into a tape drive for satisfying the MOUNT command If several PVPs entries are examined then the candidate PVP having a largest number of unallocated segments is selected If the affinity parameter indicates that it is desired to disperse LVs having such affinity parameter i e provide simultaneous access to LVs with a minimal access request conflicts to a single PVP then a PVP having no LVs or a predetermined minimal number of LVs with such affinity parameter is selected On the other hand if an affinity parameter indicates that it is desired to cluster LVs in a few PVPs sequential processing then a PVP having adequate nu
8. problems using current day data storage management prac tices requires an undue attention to assignment and storage of data using the logical volume approach It is desired that the current practices in host processors and manual proce dures required by attending personnel not be made cumber some Therefore it is desired to provide mechanisms and methods for storing a plurality of logical data storage volumes in one physical data storage volume wherein the data management activates in a host processor and of the attending personnel do not change for defining volumes It is desired to eliminate the current need for defining and assigning which physical data storage volume is to be used for storing any given logical volume and to eliminate a current need for assigning a physical volume for storing data before that data are sent to a data storage system In other words the management of data storage volumes is trans parent not seen by either the host processor nor its attend ing personnel DISCUSSION OF THE PRIOR ART Clifton et al in U S Pat No 4 310 883 describe a mass storage system wherein one disk volume IBM 3330 disk volume was emulated by two tape cartridges in an auto matic cartridge library ACL The disk volumes are termed 5 546 557 5 virtual volumes even though the system is a one for one emulation of two tape cartridges for each disk volume Clifton et al host processor automated emulated disk volume selecti
9. 25 30 35 40 45 50 55 65 18 Interactive step 95 defines to subsystem 45 a so called IBM standard label VOLI etc for created and initialized LVs but not storing any data on PVPs or LVs PVM 57 receives the information for storing same in register 96 as standard label The stored label information is inserted into each newly created LV immediate adjacent its FID Interactive step 97 completes the initialization by assigning all identified PVP VOLIDs Also the LV VOLSERs are supplied to host processors 45 for insertion into system volume catalog 50 as host processor available data storage volume identifications Subsystem 48 assigns the new LVs to an insert category Subsystem 48 then passes the VOLSERs of the LVs in the insert category to the host processors 45 as if such volumes have been actually introduced into the subsystem The host processors 45 respond to the received LV VOLSERS to add the new VOLSERSs to the system volume catalog 50 even though no such volumes actually exist The VOLSERs in range 112 are indicated as having some given data storage capacity any capacity for each VOLSER FIG 10 initialization of an LV on a selected PVP can occur after the FIG 8 illustrated subsystem initialization has been completed In FIG 10 interactive step 120 via a terminal not shown attached to a host processor 45 or by execution of an application program in host processor 45 requests host processor 45
10. 74 of the LV s VOLSER PVM 57 via PSC 52 reposition tape 30 to the PBOP of the partition receiving the new LV Then PVM 57 via PSC 52 indicates to the requesting host processor that the command identified VOLSER is mounted and data processing may ensue as indicated by numeral 132 If a new partition is established in the PVP then PVM 57 also updates PH 33 to include the newly created partition If a stack PVP is needed at step 140 then 57 selects any stack PVP for receiving the LV to be established Then at step 147 a PH 33 partition is created and PH 33 is recorded in the PH 33 partition Then steps 146 et seq are performed FIG 11 illustrates in simplified form selected peripheral commands issued by a host processor 45 to subsystem 48 Other commands not shown are also issued All of these commands employ the general arrangement shown for MOUNT command 49 and the FIG 11 illustrated com mands PSC 52 receives and decodes each of the commands as well as other commands not pertinent to an understanding of this invention and therefore not mentioned herein MOUNT command 49 FIG 6 is not repeated here Such MOUNT command represents diverse types of commands that may be used for accessing PVOs or LVs design choices that my be employed in practicing the present invention An assign to scratch host processor issued peripheral command indicates that an identified LV s are to be disas sociated from its PVP The disassoci
11. a human being In the prior art data 10 20 25 30 35 40 45 50 55 60 65 2 storage the VOLID is repeated internally in the physical volume as a machine readable copy of the VOLID Each LV has an internally stored VOLSER that identifies it as a data storage volume A logical volume is a data storage volume that is addres sable by a host processor independently of which physical volume is storing it The volume identifier VOLSER of each logical volume is independent of the physical volume iden tifier VOLID and is usually not externally available on the physical volume A physical volume partitioned PVP is a physical volume that is divided into a plurality of physically identi fiable partitions each partition is logically co extensive with a single logical volume That is one partition has one logical volume that may or may not completely occupy the one partition The medium physical locations in the physical volume are addressable by means external to the physical volume as addressable segments Each partition logical vol ume consists of an integral number of contiguous segments Partitions may be of fixed length or variable length An unpartitioned volume is a physical volume that has one partition Such a physical volume is termed as being physi cal only or PVO A partition is a portion of a physical volume that is machine identifiable either by machine sensible marks on a medium constitut
12. always remain in media means 54 One reason for such physical volume ejection control is that host processors 45 could address the PVOs while not being able to address the PVPs Only LVs residing in a PVP can be host processor addressed Any volume that is addressable by a host processor is included in system volume catalog 50 whereas the PVPs do not show up in system volume catalog 50 For maintenance purposes peripheral storage controller 52 creates a so called buffered log known in the prior art Any error conditions detected in subsystem 48 related to a PVP are included in the buffered log However such inclusion in a buffered log does not made the PVP addressable by a host processor It is noted that media means 54 preferably includes an automatic tape library ATL plus shelf storage The shelf storage is usually not managed by PVM 57 therefore the PVPs cannot be migrated to shelf storage Further the LVs when migrated to shelf storage are first moved from a PVP to a PVO for the migration It is within the scope of this invention to include a shelf storage that is managed by 57 as via terminal 59 In this instance PVPs may be moved migrated from ATL to shelf to such subsystem managed shelf storage FIG 12 includes reference to such PVP migration for illustrative purposes A migrate command is received by PSC 52 PSC 52 in decoding the migrate command actuates PVM 57 to execute the command PVM 57 first determines at step 20
13. as four tracks 310 and 312 is termed a half wrap while the entirety of the two tracks is termed a full wrap That is one complete scan in a forward direction beginning at the free end of tracks 310 to the hub end thence from the hub end of tracks 312 to the free end is one full wrap The PRV s 315 extend entirely across the tape 30 such that all tracks 310 312 have a same PRV value in each longitudinal position of tape 30 The space between longitudinally adjacent PRV s constitutes one segment of tape in each set of the tracks partition s are represented in FIG 5 by double headed arrows 316 318 320 and 321 20 25 30 40 45 50 55 65 14 Optionally each LV can have a VTOC Such a VTOC is stored in a one segment partition immediately preceding the partition holding the LV Numeral 330 between longitudi nally adjacent partition s denote a VTOC partition one segment for the respective LV s residing the respective LV containing partitions Numeral 318 indicates that a partition can extend between track half wraps The diverse number of tape segments in the LV holding partitions 316 321 indi cates that the data storage capacity of each partition is independent of the storage capacity of other partition s it is user defined and implementation dependent The for matting in each of the LV partitions is as described for FIG 4 The FID of each LV holding partition can indicate whether or not a VTOC for the LV i
14. boundaries are identified by segment boundary numbers The first segment is numbered segment 1 and has two known PRV s that identify its boundaries All partitions are similarly indicated Note that partitions other than the subsystem managed partition that contains PH 33 do not exist until an LV is created for such partitions 20 30 35 45 50 55 65 12 b A so called volume record that contains the volume serial number VOLID of the physical volume c An End of Data EOD mark at one end of PH 33 A formatted PVP has the just described format of one partition partition 0 and not others Therefore EOD is at the end of partition 0 In the library environment this first or PH 33 partition is created and managed by the library and is used to validate that the correct physical volume has been mounted This verification ensures both system and data integrity In each fixed partition sized partitioned or LV physical volume unused data storage space exists between each LV that may contain residual data from prior recordings Such data are invalid and have to be ignored In general it is not possible to read through these unused data storage spaces to reliably differentiate residual invalid FID marks from current and valid FID marks without knowledge of the starting and ending segment boundaries This segment boundary information is stored in PH 33 Once written PH 33 need never be updated since all partitions are defined
15. control means for attach ing the sub system to a host processor a plurality of addres sable media devices for removably receiving physical vol umes of data storage media means connected to the control means and to the media devices for mounting and demount ing said physical volumes of data storage media said media devices being connected to the attachment means for exchanging data signals therewith the method including steps establishing a plurality of volume serial numbers establishing a listing in said control means containing indications of a first set having a plurality of first ones of said volume serial numbers that are to be used only for identifying host processor addressable logical data storage volumes and establishing a second set of sec ond ones of said volume serial numbers that are to be used only to identify stack ones of said physical vol umes in which said host processor addressable logical data storage volumes can reside first initializing first predetermined ones of said host processor addressable logical data storage volumes including first allocating a predetermined partition of predetermined ones of said physical volumes for respective ones of first predetermined ones of said host processor addressable logical data storage vol umes and establishing addressability of said first pre determined ones of said host processor addressable logical data storage volumes by inserting predeter mined respective ones
16. current position then converts the number of segments into tape distance PSC 52 then at step 235 commands the addressed DVE to high speed access the block ID using the Milligan et al described high speed search Upon completion of the high speed search slow speed read block IDs while moving searching completes the operation Since each PVP may contain a plurality of LVs to better utilize the capacity of a tape volume concurrent conflicting access requests to two different LVs residing in a same PVP is an access conflict that has to be efficiently resolved for maintaining subsystem performance That is logical vol umes residing on the same PVP are not concurrently mount able FIGS 14 16 illustrate three solutions to access request conflicts To resolve the access request conflicts either all but one of the mount requests for the multiple LVs must be deferred possibly creating a deadlock or all but one of the LVs must be moved to another PVP If LV movement is chosen access to any data on the PVP and in the LVs is delayed while the copies are being made 10 20 25 30 35 40 45 50 55 65 26 FIG 14 illustrates copying one or more of the LVs on one PVP receiving concurrent conflicting access requests to another PVP At step 240 PVM 57 detects concurrent conflicting access requests to a plurality of LVs residing on one PVP Each received MOUNT command remains queued until subsystem 48 reaches it for execut
17. data storage sub system to a host processor a plurality of addressable media devices for removably receiv ing physical volumes of media means connected to the control means and to the media devices for mounting and demounting said physical volumes of media on and from said media devices said media devices being connected to the attachment means for exchanging data signals therewith the method including the steps establishing in the control means a plurality of volume serial numbers establishing a listing in said control means containing indications of a first set having a plurality of first ones of said volume serial numbers that are to be used only for identifying host processor addressable logical data storage volumes and establishing a second set of sec ond ones of said volume serial numbers that are to be used only to identify stack ones of said physical vol umes in which said host processor addressable logical data storage volumes can reside establishing in the listing a plurality of affinity categories establishing a first one of said affinity categories for dispersing said host processor addressable logical data storage volumes having said first one affinity among a maximal number of said physical volumes and establishing a second one of said affinity categories for clustering said host processor addressable logical data storage volumes having said second one affinity cat egory initializing predetermined ones of said
18. of said host processor addressable data storage volumes and that was previously had a scratch category and physical volumes that are in a partition category that respectively are storing one or more of said a plurality of said host processor addressable logical data storage volumes 55 The method set forth in claim 54 including the steps in said listing maintaining two affinity categories maintaining a first affinity category indicating that a minimal number of said host processor addressable logical data storage volumes are to reside in each of said plurality of physical volumes having ones of said host processor addressable logical data storage vol umes residing therein in said control means responding to a said mount com mand indicating said first affinity category for selecting one of said plurality of said physical volumes that includes a minimal number of said host processor addressable logical data storage volumes having said first affinity category for receiving and storing said mount command indicated host processor addressable logical data storage volume maintaining a second affinity category for indicating that a maximal number of said host processor addressable logical data storage volumes are to reside in a minimal number of said plurality of physical volumes and in said control means responding to a said mount com mand indicating said second affinity category for selecting a second one of said plurality of said
19. of the logical volumes from the one physical volume to other physical volumes If a data movement solution is chosen access to any data on the one physical volume is delayed while the copies are made This solution may not always be practical for many data processing environments Access to the first byte of data stored in a physical tape volume may be slower than if but one logical volume is stored in each physical tape volume That is since the beginning of any logical volume is usually displaced from the normal loading point the tape has be to moved to position the beginning of a logical volume at the tape drive transducer or head Depending on how data storage space is managed for logical volumes each addressable logical volume is stored in a partition in a physical volume the size number of data bytes of a logical volume data storage space required for a logical volume must accommodate volume size can be expected to be unpredictable One solution is to prevent appending data to data currently stored in a logical volume that is full Such partitions as used herein are logically co extensive with logical volumes High speed searches on the tape are based on segments or position reference values PRVs as will become apparent and as set forth in Milligan et al supra Some prior art documents use the term partition in a same vein as the term segment is used herein To solve the above stated problems as well as other
20. processor issued locate command for said given data block including identifying said given block 1D said given tape location and identifying said first host processor 10 20 25 35 40 50 55 60 65 54 addressable logical data storage volume on said second physical volume said volume manager means having locate means responding to said locate command for accessing said volume map means for determining that said first host processor addressable logical data storage vol ume resides in said second magnetic tape physical volume said locate means having adjustment means for changing the given tape location indicated in the locate command to said different position on said second physical vol ume including arithmetically differencing a beginning physical position of said one host processor address able logical data storage volume in said first and sec ond physical volumes and arithmetically changing the memorized location by arithmetically combining said difference and said memorized location and said peripheral controller means actuating said second media device for moving the magnetic tape of the second physical volume to said changed location for accessing said given data block 61 A method of operating a peripheral data storage sub system programmed control means in the peripheral data storage sub system for controlling its operation and attachment means connected to the control means for attach ing the
21. sable logical data storage volumes that were in said Stack category 5 546 557 57 receiving a mount command from an attached host pro cessor into said control means that includes an address of one of said media devices and an addressed volume serial number wherein said addressed volume serial number has a value respectively indicating that the addressed volume serial number identified host proces sor addressable logical data storage volumes is to be or is stored in a physical volume either in said stack or partition categories or in said scratch and unitary cat egories in said control means checking said listing for determin ing whether or not an initialized one of said host processor addressable logical data storage volumes is identified by said addressed volume serial number if said checking shows that no initialized logical data storage volume is identified by said addressed vol ume serial number then selecting one of said physi cal volumes as a selected one physical volume in said stack or scratch category indicated by said mount command identified volume serial number for receiving said addressed host processor addressable logical data storage volume mounting said selected one physical volume in said addressed media device as mounted physical vol ume then allocating a predetermined addressable partition of said mounted physical volume for receiving and storing a host processor addressable logical data storag
22. second physical volume said second data storage volume and updating said data base to show that said second data storage volume resides in said second physical volume and erasing any indication of said data storage volume residing in said first physical volume and updating said data base to show that said second physical volume is mounted on said second one of said media devices and in the control means supplying an indication to the attachment means that said second data storage volume is mounted on said second one of said media devices and is ready to be accessed 38 The method set forth in claim 36 further including the steps indicating in said data base that first and second data storage volumes reside in a first one of said physical volumes 10 15 30 35 45 50 55 44 mounting said first one of said physical volumes in a first one of said media devices for enabling a current access to said first data storage volume in said control means receiving from said attachment means a second mount command to mount said second data storage volume in a second one of said media devices holding any response to said second mount command from said control means until said current access to the first physical volume is completed detecting that said current access is completed establishing a plurality of paths over which data may be transmitted from any of said media devices to said attachment means including establi
23. selected migrate volume then actuating the volume manager means to delete said VOLID of said one of said physical volumes from said data base means to update said data base means to show that the certain logical volume is disassociated from said first one of said physical volumes 24 In the apparatus set forth in claim 15 further includ ing in combination 5 20 50 55 60 38 media storage means connected to said moving means for yielding and receiving said magnetic tape physical volumes for transport to and from the respective media drives an IO station in the media storage means for yielding and receiving physical volumes to and from said volume moving means and having a manual port for manually receiving and yielding physical volumes said peripheral controller means having migrate com mand means connected to the attachment means for receiving host processor issued migrate commands from the attachment means that indicate a VOLSER volume serial number for identifying one of host processor addressable logical data storage volumes to be migrated said migrate command means connected to the volume manager means for verifying that the migrate command VOLSER volume serial number is for either a host processor addressable logical data storage volume that resides by itself in a physical volume or resides with other host processor addressable logical data storage volumes in one physical volume said migrate com mand me
24. the eject means for selecting and indicating a given number of said identified ejectable physical volumes for migrating addressed ones of said host processor addressable logical data storage vol umes to said IO station said volume manager means having migrate controlling means connected to said migrate initiating means for accessing said data base means for identifying all of said addressed ones of said host processor addressable logical data storage volumes said migrate controlling means responding to the migrate initiating means indicating that all of the addressed ones of said host processor addressable logical data storage volumes to actuate the peripheral controller means to move said addressed ones of the host proces sor addressable logical volumes to said identified eject able physical volumes and then to actuate the volume moving means to move said identified ejectable physi cal volumes to said IO station and said volume manager means responding to said migrate controlling means to update said data base means 22 In the apparatus set forth in claim 15 further includ ing in combination said data base means having first and second portions each said portions having a plurality of entries for identifying data storage volumes said first portion having a plurality of physical volume identifying ones of said entries each of said physical volume identifying entry having a volume id VOLID 5 546 557 37 field for s
25. the invention be practiced in an automatic library environment Ejection of LV s from the library is effected by storing the LV in an ejectable physical volume Categories including categories based on affinity charac teristics facilitate volume selection and management The categories define characteristics that assist management of the data the LV s and physical volumes Diverse media and data storage track layouts can be used in the physical volumes The data storage subsystem may contain physical volumes that store data only as a single volume physical volumes that contain one or more LV s scratch physical volumes designated for either single vol 20 25 30 35 45 50 55 60 65 8 ume usage or LV usage Diverse media such as magnetic tape optical tape magnetic disks or optical disks may be employed alone or in a mixed media library The foregoing and other objects features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings DESCRIPTION OF THE DRAWING FIG 1 illustrates known prior art volume creation estab lishment methods FIG 2 illustrates a method for the creation establishment of data storing volumes in accordance with the present invention FIG 3 illustrates a prior art magnetic tape format FIG 4 illustrates in simplified form a multi volume tape format c
26. to send an error condition signal UNIT CHECK to the access requesting host processor The UNIT CHECK may indicate that the requested LV is not available but can be made available by requesting a MOUNT of such volume on the same DVE in the subsystem The second requesting host processor at step 264 has several options to respond to the UNIT CHECK The second requesting host processor may wait a predeter mined time for retrying access to the LV may abort its current job that caused the access request or may abort a new Job for which the access request was made 5 546 557 27 FIG 17 illustrates appending data to data stored in an LV Care is exercised not to record any data beyond the extent of the LV i e all recording is contained to the partition that is co extensive with the LV Step 280 assumes that PSC 52 is writing data in an addressed LV in a PVP mounted in one of the DVEs 53 During recording in step 280 PSC 52 is continually monitoring in step 281 the position of the tape with respect to the recording transducer not shown as by tracking the position by the Milligan et al disclosed reel tachometer or any other known mechanism If a LEOP FIG 4 is detected recording is immediately aborted and in step 252 a UNIT CHECK is sent to the appending data com manding host processor Also the write commanding host processor aborts its writing program at step 283 and ends volume processing writes known so called trailer labels Abor
27. volumes without any or a minimal host processor intervention GLOSSARY AND DEFINITIONS OF TERMS The following terms are used in this document A data storage volume or volume is a unit of a data storage medium that is separately addressable and is identified by a volume identifier As used below only for the purpose of consistency in terminology the volume identifier for a logical volume is termed VOLSER while the volume iden tifier for a physical volume is termed VOLID In the prior art VOLSER and VOLID have been used interchangeably To effect access to data storing locations in a volume a host processor requests that an addressed volume be mounted in an addressed device for accessing data storage space of such volume A physical volume is a volume that is always a physical package such as a tape cassette or cartridge a disk cartridge and the like Each physical volume is independently mount able into a device to provide access by a host processor to its data storage space In the prior art such physical volumes are directly addressable by the host processor In practicing this invention a plurality of logical volumes LV are located in but transportable from a physical volume To access data storage space in a physical volume having LVs only the LVs are addressed by a host processor This physical volume is not separately directly addressable by a host processor The volume identifier VOLID on a physical volume is readable by
28. when the volume is first formatted and before any partition is logically created to make it addressable as an LV Changes to the partitioning sizes requires rewriting PH 33 In the variable length partition or variably sized LV format multiple partitions of variable length are created after the PVP is initially formatted as a variable partition PVP Such variable sized partitioning is such that a continu ous formatting from the beginning of the first partition to the end of the last partition is provided The first or PH 33 partition on the volume contains PH 33 that contains a variable partition volume header having the following infor mation and the information shown in TABLE I a A Variable Partition Mark FPM that indicates variable length partitions exist in the PVP b A so called volume record that contains the volume serial number VOLID of the PVP c An End of Data EOD mark In the illustrated embodiment all of the above mentioned marks are in usual or so called legal data pattern form Therefore each of the marks is a physical data block having information bearing signals respectively indicating a tape mark EOD etc In a library environment this first or PH 33 partition in a variably sized PVP is created when the PVP is to receive an LV The first partition is then managed by the library as later described for validating that a correct physical volume has been mounted Whenever either a fixed or variably sized partit
29. 1 AUTOMATIC CLASS SELECTION 122 157 dura DANS VOLSER EXIST T YES SELECT PVP STORING LV NOT EXIST FIND PVOL THAT CAN PVM SEARCHES FOR VOLSER CONTAIN LV THEN CREATE LV IF NO VOLSER SELECT PVOL FOR CREATING AN LV PVP SELECTION CRITERIA CATEGORY FILTER T AFFINITY FILTER Q EXPIRATION DATE NO MOST FREE SPACE CURRENTLY MOUNTED 130 YES MOUNT PVP TO DRIVE 140 lt gt 145 FIND EMPTY PARTITION 146 RECORD FID HOST PROCESSOR COMMANDS REWIND AND UNLOAD 131 POSITION TAPE TO PRV FOR THE LV SELECT PVP FROM THE STACK CATEGORY Zx RECORD FID 32 RECORD PH 33 HDR1 134 PVM UPDATES DB AND STORES PVOL U S Patent Aug 13 1996 Sheet 8 of 11 5 546 557 PVP PHYSICAL VOLUME PARTITIONED PVO PHYSICAL VOLUME ONLY SELECT MIGRATION PROCESSING PVP TO LIBRARY PVO 202 215 PRIOR ART SELECT TWO MIGRATION DEVICES 203 216 MOVE PVP TO LOAD TWO IO STATION PVP S 217 MOVE LV S MOVE PVP TO STORAGE CUBICLE ae YES 209 UPDATE DATA BASE U S Patent Aug 13 1996 5 546 557 Sheet 9 of 11 FIG 13 LOCATING BLOCKS IN LV S READ BLOCK ID 225 BLOCK ID COMMAND IS ISSUED TO FIND LOGICAL BLOCK AFTER WHICH DATA BLOCKS WILL BE ADDED SUBSYSTEM RETURNS TO HOST PROCESSOR THE PHYSICAL REFERENCE INDEX AND THE NUMBER OF THE LOGICAL BLOCK HOST PROCESSOR SAVES THE PARAMETER INFORMATION FOR LATER FINDING DATA BLOCKS O BE APPENDED
30. 2 The apparatus set forth in claim 1 further including in combination a dedicated media drive connected to said volume moving means for receiving and ejecting physical volumes from and to said volume moving means said dedicated media drive being addressable only by said peripheral controller means and said volume manager means actuating said peripheral controller means to select said dedicated media drive each time one of said host processor addressable logi cal data storage volumes is to be copied between two of said physical volumes 33 The apparatus set forth in claim 1 further including in combination said host processors having a system volume catalog of said host processor addressable logical data storage volumes that includes a plurality of volume serial numbers for said host processor addressable logical data storage volumes including volume serial numbers that identify no host processor addressable data stor age volume in said volume map means said volume serial numbers being arranged into groups that each respectively indicate a predetermined category of host processor addressable logical data storage volumes and 5 546 557 41 said system volume catalog having no volume serial numbers of said physical volumes 34 A method of operating a peripheral data storage sub system programmed control means in the peripheral data storage sub system for controlling its operation and attachment means connected to the
31. 5 whether the migration is for a PVO or an LV If the command is for an LV migration then PVM 57 whether or not a plurality of LVs are to be migrated is checked Also whether the plural LV migration includes a separate migration of one or more LVs independently of which PVP currently is storing the LV is checked To migrate a PVO any known or prior art migration is used in step 202 Such migration of a PVO can be from shelf storage into ATL of means 54 from ATL to shelf storage exit from the data processing installation or entry into the data processing installation Upon completing migration of the PVO PVM 57 updates the FIG 7 illustrated data base to reflect the migration reports completion of the migration to the commanding host processor and exits migration over path 210 The PVO migration is effected by PVM 57 commanding media storage means 54 to move a PVO to or from IO station 55 Manual access to IO station 55 moves the PVO to and from shelf storage or to another data processing installation Migrating LV s involve new and different procedures As stated above PVP s are not addressable by a host processor therefore cannot be commanded to be migrated Also since LV VOLSERs cannot be transferred from PVM 57 control of an ATL there is no migration of PVP s in the illustrated embodiment to shelf storage Migration of LV s to shelf storage includes moving the addressed LV from a PVP to a PVO an ejectable physical volume then migr
32. 87 500 2 1994 Stoppani Jr w 395 600 5 327 535 7 1994 et al 395 440 15 OOO O O O DAN NT US005546557A Patent Number 5 546 557 45 Date of Patent Aug 13 1996 OTHER PUBLICATIONS MS DOS operating system pp 149 160 1991 Introduction to IBM Direct Access Storage Device 1990 pp 5 8 to 5 9 Dictionary of Computing 1987 pp 276 462 464 Isol IEC 10288 pp 194 204 Primary Examiner Thomas C Lee Assistant Examiner Moustafa Mohamed Meky Attorney Agent or Firm M W Schecter D A Shifrin H F Somermeyer 57 ABSTRACT A peripheral data storage subsystem has means for respond ing to a MOUNT command received from a host processor to create and mount a host processor addressable logical data storage volume Such logical data storage volume has a serial number VOLSER indicated in the MOUNT com mand The logical data volume is assigned a predetermined area of a physical data volume such area being termed a partition The illustrated embodiment shows a tape sub system in which the partitions are accessed by a control using a reel tachometer that identifies segments of the tape Each partition has a number of the tape segments Controls and methods are described for initializing the subsystem for effecting the automatic volume creation appending data into a logical volume how logical volumes are made to be portable moving logical volumes amongst dive
33. OF SEVERAL PHYSICAL VOLUMES INCLUDING AUTOMATICALLY CREATING LOGICAL VOLUMES IN PERIPHERAL DATA STORAGE SUBSYSTEM DOCUMENTS INCORPORATED BY REFERENCE Clifton et al U S Pat No 4 310 883 is incorporated for its showing of a host processor allocating data storage space in a virtual volume selected from a group of such virtual logical volumes Gelb et al U S Pat No 5 018 060 is incorporated for its showing of a host processor using automatic storage class selections for enabling enhanced data storage volume selec tion in allocating data storage space in a data storage volume for a data set Milligan et al U S Pat No 4 393 445 is incorporated by reference for its showing of a peripheral data storing tape subsystem in which the subsystem generates and uses physi cal reference values PRV s useful for rapidly accessing blocks of data stored in any one of a plurality of magnetic tapes Co pending commonly assigned application for patent by Kulakowski et al Ser No 07 816 590 filed Jan 3 1992 now U S Pat No 5 303 214 is incorporated by reference for its teaching of affine groups of data sets and data storage volumes logical or physical in a multi media automatic media library data storing subsystem FIELD OF THE INVENTION This invention relates to peripheral data storage sub system more particularly to such subsystems that can auto matically create data storing logical or virtual volumes and the management of such
34. OF VOLUME LEOV LOGICAL END OF VOLUME PEOV PHYSICAL END OF VOLUME FID FORMAT IDENTIFICATION BLOCK FIG 4 HUB EDD dd 32 33 33A S BOP BEGINNING OF PARTITION LBOP LOGICAL BOP EOP END OF PARTITION LEOP LOGICAL EOP U S Patent Aug 13 1996 Sheet 3 of 11 5 546 557 FIG 5 20 TT o 311 SSSR Se RI PRV L9 f NE By 00 7381 312 PVP PORTION OF DATA BASE FIG 7 69 PERIPHERAL DATA BASE VOLID LV INDEX CATEGORY DATETIME REQUEST LAST JOB MOUNTED AFFINITY HISTORY LV PORTION OF DATA BASE 6 74 START PARTITION VOLSER VOLID STOP PRV NO E OU MOUNT esa HISTORY JOBID DATE TIME POINTERS U S o FIG 6 PROCESSOR PERIPHERAL STORAGE CONTROLLER PSC PERIPHERAL VOLUME MANAGER PVM DEVICES DRIVES DVE S SHELF STORAGE MANUAL 55 LEGEND AUTOMATIC TAPE LIBRARY ATL AUTOMATIC CARTRIDGE LIBRARY ACL o Patent Aug 13 1996 Sheet 4 of 11 5 546 557 SYSTEM VOLUME CATALOG 50 VOLSER VOLID jx js PVP VOLUME MAP ame
35. ON TAPE AFTER THE IDENTIFIED LOGICAL BLOCK LOCATE BLOCK ID 230 RECEIVE LOCATE BLOCK ID COMMAND HAVING THE FIRST STARTING PRV PVM READS THE START PRV FROM FIELD 85 IN THE DATA BASE PVM CHANGES THE RECEIVED START PRV TO THE DATA BASE PRV PSC CALCULATES THE SEGMENT SIZE BASED ON DIRECTION BIT ADJUSTED SEGMENT NUMBER FOR CONTROLLING HIGH SPEED SEARCH LOCATE BLOCK ID COMMAND IS EXECUTED AS A HIGH SPEED SEARCH U S Patent Aug 13 1996 FIG 14 240 PVM DETECTS ACCESS REQUESTS TO TWO LV S IN ONE PVP SEND NOT READY SIGNAL TO HOST 242 SELECT A TARGET PVP HAVING THE SAME CATEGORY AS SECOND REQUESTED LV S 243 MOUNT TARGET PVP S 247 SEND LONG BUSYTO THE ORIGINAL HOST 244 COPY SECOND LV S FROM FIRST PVP TO RESPECTIVE MOUNTED TARGET PVP S 245 UPDATE DATA BASE 246 SEND MOUNT COMPLETED RESPONSE TO SECOND REQUESTING HOST PROCESSOR Sheet 10 of 11 5 546 557 FIG 16 260 PVM DETECTS ACCESS REQUEST CONFLICT TO MULTIPLE LV S IN A FIRST PVP SEND UNIT CHECK TO FIRST REQUESTING HOST IN HOST PROCESSOR WAIT ABORT CURRENT JOB ABORT NEW JOB EXIT 248 SEND NO LONGER BUSY TO ORIGINAL REQUESTING HOST PROCESSOR U S Patent Aug 13 1996 Sheet 11 of 11 5 546 557 FIG 18 FIG 17 300 APPEND DATA 305 280 WRITING DATA IN AN LV 306 301 307 253 5 546 557 1 SYSTEM FOR STORING AND MANAGING PLURAL LOGICAL VOLUMES IN EACH
36. P usual data processing activities ensue all as indicated by numeral 132 When the requesting host processor 45 determines that the data processing has been completed then at step 133 the requesting host processor commands the subsystem to unload demount the mounted LV A PVP with unused or available established partitions or unassigned segments typi cally stays mounted in a tape drive for receiving a newly established LV i e a volume miss has occurred because an mount command identified VOLSER has no corresponding established LV If at step 124 PVM 57 determines that no LV exists for the VOLSER then PVM 57 will automatically establish an LV FIG 10 having the requested VOLSER A category or affinity value can be used to implicitly indicate desired LV data storage capacity In preparing for LV establishing an LV at step 140 PVM 57 determines using category and affinity parameters in MOUNT command 49 FIG 6 if a PVP exists with LV s preferably mounted on a tape device that can receive the requested LV if none are identified then a PVP in the stack category is selected The FIG 7 illustrated data base is searched in the category field CAT for finding VOLIDs that can be used for storing the received VOLSER indicated LV If such a PVP is found preferably a mounted PVP then the available data storage space is checked not shown Such checking includes summing the number of segments for the data base LV s VOLSERs existing in the
37. United States Patent Allen et al 54 75 73 21 22 51 52 58 56 SYSTEM FOR STORING AND MANAGING PLURAL LOGICAL VOLUMES IN EACH OF SEVERAL PHYSICAL VOLUMES INCLUDING AUTOMATICALLY CREATING LOGICAL VOLUMES IN PERIPHERAL DATA STORAGE SUBSYSTEM Inventors Vincent K Allen Robert S Goncharsky Richard A Ripberger all of Tucson Ariz Assignee International Business Machines Corporation Armonk N Y Appl No 75 936 Filed Jun 14 1993 Int Che rau uhuy a hu ha 06 13 24 US usina 395 438 395 404 395 823 369 34 364 247 3 364 248 1 364 248 2 364 DIG 1 Field of Search 395 275 425 395 600 650 438 404 823 369 34 References Cited U S PATENT DOCUMENTS 4 310 883 1 1982 Clifton et al 395 600 4 393 445 7 1983 Milligan et al 360 72 2 4 430 727 2 1984 Moore et al wee 395 442 395 284 4 837 680 6 1989 Crockett et al 4 989 191 1 1991 369 33 5 018 060 5 1991 Gelb et al 395 600 5 129 088 7 1992 Auslander 395 700 5 163 134 11 1992 Kakuse et al 395 823 5 197 055 3 1993 Hartung et al 369 34 5 210 866 5 1993 Milligan et al 395 182 04 5 239 650 8 1993 Hartung et al 395 650 5 283 875 2 1994 Gibson et al we 395 404 5 2
38. a storage volume to said second displacement location 7 In the apparatus set forth in claim 1 further including in combination initialization means connected to said volume manager means for actuating the volume manager means to enter volume serial number data into said volume map means said initialization means including first data means for actuating said volume manager means to insert identifying data into said volume map means for identifying a first sub plurality of said physical volumes as partitioned physical volumes each of said first sub plurality of said physical volumes having a respective VOLID volume serial number and a visually sensible copy of said respective VOLID volume serial number all of said VOLID volume serial numbers of said first sub plurality of said physical volumes being unique such that none of the VOLID serial numbers in said first sub plurality of physical volumes are dupli cated second data means for actuating said volume manager means to insert identifying data into said volume map means for identifying a set of unique VOLSER volume serial numbers for identifying respective ones of said host processor addressable logical data storage vol umes a first predetermined subset of said VOLSER volume serial numbers being different from any of said VOLID volume serial numbers third data means for actuating said volume manager means to insert identifying data into said volume map means for further indi
39. achment means that the writing is aborted selecting another tape including mounting said another tape on a tape drive and recording said data to be appended on said another tape 46 The method set forth in claim 34 wherein each of said physical volumes movably mount a data storage medium said storage medium being an elongated flexible magnetic data storage tape each of said media devices having medium displacement detecting and indicating means for detecting and indicating displacement of said tape of a physical volume mounted therein from a medium reference position said detecting and indicating means indicating said displacement in segments of said magnetic tape said data recorded on the medium arranged in blocks each block having a block ID mounting a physical medium in one of said media devices 10 20 25 30 35 40 45 50 55 60 65 48 detecting and indicating a block ID of a data block recorded in a given one of said host processor addres sable logical data storage volumes in said mounted physical volume reading and storing the block ID in said listing in said detecting and indicating means detecting and indicating a displacement of said recorded block from said reference position as being in one of said seg ments in said control means storing said indicated displacement in said listing with said block ID and supplying said block ID said indicated displacement of Said recorded bl
40. aid partitions in first predeter mined ones of said physical volumes and in said control means clustering a variable number of said segments in each of said partitions in second predeter mined ones of said physical volumes such that said assigned host processor addressable logical data stor age volumes in each of said second predetermined ones of the physical volumes can have different data storage capacities 50 The method set forth in claim 48 wherein said magnetic tape having a plurality of data storage tracks arranged in a serpentine pattern such that a forward tape scanning direction in a first subset of the data storage tracks is from a free end of said magnetic tape to a hub end of said magnetic tape mounted on a reel of tape and a forward tape scanning direction in a second subsystem of the data storage tracks if from said hub end toward said free end said first and second subsets including tracks in a respective half wraps that are interleaved across the magnetic tape laterally to the longitudinal length of the magnetic tape such that scanning the first subset of data storage tracks including the Steps in said detecting and indicating means counting said partitions in a first direction of count and scanning the 5 546 557 49 second subset of data storage track results in counting said partitions in a second direction of count that is reverse to said first direction one of said directions of count being an ascending co
41. al block but are from BOT Therefore the displacement in segment numbers from BOT to PBOP of the LV being addressed is added to the segment number contained in the locate command When PRV s are linear then simple addition is usable for identifying the partitions When PRV s are not linear then a function PRV f partition number where is the PRY used in the locate read block ID command and is the current actual PRV on the tape in the PVP The values of the equation set forth above are empirically determined from each tape format therefore are not described herein Block number field 170 contains the block number assigned to the 10 20 25 30 35 40 45 55 60 65 22 logical block within the VOLSER identified LV in the MOUNT command 49 that preceded host processor 45 issuing the locate command Referring next to FIG 12 migration of LV s PVOs and PVPs within media storage means 54 and the like is explained One or more migrate commands may be used in connection with host processors 45 This description is based on one host processor issued migrate command for all types of volumes it is to be understood that each separate migration process may be achieved by responding to respec tive separate host processor issued migrate commands not shown In an early constructed embodiment the PVOs were the only ejectable migrate out of the media means 54 while PVPs were not ejectable must
42. ans connected to the control means for attaching the data storage sub system to a host processor a plurality of addressable media devices for removably receiving physical volumes of media means connected to the control means and to the media devices for mounting and demounting said physical volumes of media on and from said media devices said media devices being connected to the attachment means for exchanging data signals therewith said program product comprising a data storage means having machine sensible program instructions includ ing program instructions for establishing in the control means a plurality of volume serial numbers program instructions for establishing a listing in said control means containing indications of a first set having a plurality of first ones of said volume serial numbers that are to be used only for identifying host processor addressable logical data storage volumes and establishing a second set of second ones of said volume serial numbers that are to be used only to identify stack ones of said physical volumes in which said host processor addressable logical data storage volumes can reside program instructions for establishing in the listing a plurality of affinity categories establishing a first one of said affinity categories for dispersing said host proces sor addressable logical data storage volumes having 20 25 35 40 45 50 55 65 60 said first one affinity among a maxi
43. ans rejecting the migrate command if the migrate command is received in a first transmission of said migrate command from said attachment means and accepting the migrate command if it is a second trans mission by said attachment means of said received migrate command said migrate command means actu ating said attachment means to reject the migrate command on said first reception of said migrate com mand and to accept the migrate command on its second reception said peripheral controller means having migrate initiating means connected to the migrate command means for responding to said accepted migrate command for actuating said volume manager means to migrate an addressed one of said host processor addressable logi cal data storage volumes that reside in said one of said physical volumes said volume manager means having migrate controlling means connected to said migrate initiating means for accessing said data base means for identifying said migrate command VOLSER identified volume stored in one of said physical data storage volume and said migrate controlling means responding to the request to migrate initiating means indicating that said migrate command VOLSER identified volume is to be migrated for actuating the peripheral controller means to move said migrate command VOLSER identified host pro cessor addressable logical data storage volume from said one physical volume to another physical volume then actuating the volume moving
44. ans to select a second one of said physical volumes identified in said listing by said addressed volume serial number for mounting in said addressed media device program instructions for actuating said control means for mounting said second selected physical volume in said addressed media device as being said logical data storage volume and program instructions responsive to said checking showing that the addressed serial number is not a volume serial number in said first plurality of serial numbers for actuating said contro means to reject the received mount command as not identifying any data storage volume including if said received mount command identifies a volume serial number in said second plu rality of volume serial numbers 65 A program product for operating a peripheral data storage sub system programmed control means in the peripheral data storage sub system for controlling operation of the data storage sub system having attachment means connected to the control means for attaching the sub system to a host processor a plurality of addressable media devices for removably receiving physical volumes of media trans port means connected to said control means and to the media devices for responding to said control means for mounting and demounting said physical volumes of media said media devices being connected to the attachment means for exchanging data signals therewith said program product comprising data storage mean
45. apparently is to automatically assign data sets to data storage volumes based on established criteria classes that use inferences or hints identifying the data set to select a data storage volume Gelb et al like Clifton et al use already established volumes based on manual actuation of the system to recognize such physical or emulated volumes The IBM Technical Disclosure Bulletin Vol 35 No 5 October 1992 pp 17 20 describes improving data storage volume management by using categories category is defined for including data storage volumes having a com mon attribute Such common attributes include scratch vol umes expiration dates common user type of volume host processor data related to a job or a set of Jobs volumes to be transferrer or migrated to a scratch category and the like mount by category is indicated as mounting any volume that is a member of a category One example is mounting one volume from a scratch category Co pending commonly assigned application Kulakowski et al Ser No 07 816 590 filed Jan 3 1992 now U S Pat No 5 303 214 shows an automatic media library subsystem that uses an affinity characteristic for managing data storage volumes That is those data storage volumes storing data that have a predetermined functional relationship host pro cessor determined have an affinity Affinity classes are established Cartridges that are members of a same affinity class must be entered and exited from t
46. areas 37 38 resides next to partition 2 Numeral 39 indicates that additional partitions having LV s are appended to the illustrated partitions up to the LEOV not shown of tape 30 Each of the LV s in volume portions 34 36 and 38 of the illustrated partitions have an EOD indicating end of data in the respective LV s In a magnetic tape 30 having fixed size partitions i e all of the multiple partitions have like sizes in terms of numbers of segments in each of the respective partitions Segments may be used to find or identify partition boundaries If the segments have a sufficient resolution all partitions of fixed sized should have the same data storage capacity If the segments vary in size with reel rotational positions see Milligan et al supra then fixed sized partitions can have differing numbers of segments The first partition in a tape in each fixed partitioned physical volume contains a fixed partition volume header PH 33 This first partition preferably does not have any system number i e is not accessible by a host processor Therefore there is no need for any system control marks such as tape marks in the PH 33 partition PH 33 being in its own partition is updatable by the subsystem Each PH 33 as partially shown in TABLE I above contains the following information 2 A Fixed Partition Mark FPM that defines in either a list or a code representing a documented list the boundaries of all existing partitions The
47. at is each LV appears as a true addressable data storing volume to the host processors that is mountable in a peripheral data storage subsystem Of course data are included in catalog 50 indicating that the volume is a logical or virtual volume Peripheral storage controller PSC 52 also termed control unit storage director and the like attaches the subsystem 48 to host processor 45 PSC 52 includes the usual daia flow circuits error detection and correction circuits data buffers or caches device attaching circuits inter PSC communica tion circuits and the like A plurality of magnetic tape drives hereinafter DVE s are attached to PSC 52 in a usual manner Physical media storage 54 receives stores and supplies PVOs and PVPs storage media such as tape cartridges tape reels etc from for and to addressed ones of the DVE s 53 In a preferred form of practicing the present invention storage 54 includes an automatic tape library of usual design In this preferred form a medium cartridge accessor not shown fetches PVPs from storage cubicles for automatic insertion into addressed ones of the DVEs A usual long term manually service shelf storage in proximity to the automatic library ies ATL or ACL is provided The operational relationship of such shelf storage to the libraries will become apparent In accordance with the present invention a peripheral volume manager PVM 57 is added to subsystem 48 PVM 57 provides automatic data s
48. ated between a predetermined one of said partitions and said second end of the tape 27 The apparatus set forth in claim 1 further including in combination affinity means in the data base means for indicating that first predetermined ones of said host processor addres sable logical data storage volumes having respective affinity properties that are identical with affinity prop erties of second predetermined ones of said host processor addressable logical data storage volumes and said second means having volume assignment means connected to the affinity means for assigning said first predetermined ones of said host processor addressable logical data storage volumes to respective ones of a set of a plurality of said physical volumes that include said indicated affinity 28 The apparatus set forth in claim 27 further including in combination said indicated affinity means indicating that a minimal number of said host processor addressable logical data storage volumes are to reside in each of said plurality of physical volumes in a first set and volume assignment means in said volume manager means for selecting one of said plurality of said physical volumes that includes a minimal number of said host processor addressable logical data storage volumes for receiving and storing said mount command indicated host processor addressable logical data storage vol ume 29 The apparatus set forth in claim 27 further including in combina
49. ating the PVO to shelf storage 5 546 557 23 However assuming that a shelf storage stores physical volumes PVO and PVP having a range of serial numbers for the automatic library ATL migrating a PVP to a library from shelf storage within means 54 involves at step 203 PVM 57 sending a message to the shelf storage area such as via terminal 59 to manually fetch the PVP and load it into IO station 55 PVM 57 then commands the library at step to fetch the PVP in the IO station and store it in a designated storage cubicle The FIG 7 illustrated data base is updated in step 209 to reflect the PVP migration Such updating is deletion of the data content of VOLID field of the LV entry 72 During the LV migration the VOLSER identifying the LV is disassociated from any PVP therefore is available to identify another LV The volume of data is identified by the VOLID of the PVO carrying the volume of data to shelf storage Host processors 45 update system volume catalog 50 to reflect the change of the volume of data from the VOLSER of the migrated LV to the VOLID of the migrated PVO If shelf storage can store PVPs under subsystem 48 control then a PVP to shelf migration not shown can be effected The migrate command identifies one or more LVs to be to migrated The PVP is never addressed by the migrate command PVM 57 selects the PVP to be migrated based upon identified LVs to be migrated For migrating an LV the FIG 11 illustrated mig
50. ation is achieved by removing the addressability of the LV by deleting the PVP identification in field VOLID from the LV s data base entry 72 The assign to scratch command has command indica tor field 150 VOLSER s command modifying parameter field 152 addressed LVs and an optional priority of execu tion field 153 Field 153 indicates an order of execution of this command with respect to other host processor issued peripheral commands This command can be considered as a command to change the category of the LV Execution of this command does not require mounting the addressed LV onto a tape drive The entire command is executed by the above described deletion to the LV portion 66 of the periph eral data base PVM 57 updates the linked list of LV s for the affected PVP to reflect deletion of the LV The LV pointers field is erased with the pointers fields in logically adjacent LV entries of the PVP linked list are changed to reflect removal or disassociation of the addressed LV from the PVP Optionally data security may require that the data content of the disassociated LV be erased In that event subsystem 48 mounts the addressed LV on the subsystem tape drive 53A for erasing the addressed LV s data content 5 546 557 21 A migrate volume command has command identifier field 155 device address field 156 VOLSER s command modifying parameters field 157 address LVs or PVPs to identify the volumes to be migrated and target locatio
51. ber has a value respec tively indicating that the addressed volume serial num ber identified host processor addressable logical data storage volumes is to be or is stored in a physical volume either in said stack or partition categories or in said scratch and unitary categories program instructions for actuating said programmed con trol means to check said listing for determining whether or not an initialized one of said host processor addres sable logical data storage volumes is identified by said addressed volume serial number program instructions for actuating said programmed control means if said checking shows that no initial ized logical data storage volume is identified by said addressed volume serial number then selecting one of said physical volumes as a selected one physical volume in said stack or scratch category indicated by said mount command identified volume serial number for receiving said addressed host processor addressable logical data storage volume program instructions for actuating said programmed control means for mounting said selected one physi cal volume in said addressed media device as a mounted physical volume program instructions for then actuating said control means for allocating a predetermined addressable partition of said mounted physical volume for receiv ing and storing a host processor addressable logical 5 546 557 63 data storage volume having said addressed volume serial number and t
52. ble logical data storage volumes by inserting respective ones of said volume serial numbers of said first set in said host processor addressable logi cal data storage volumes on respective ones of said physical volumes including initializing fewer of said host processor addressable logical data storage vol umes that the number of said established first volume serial numbers in said control means listing said initialized host proces sor addressable logical data storage volumes having said first volume serial numbers respectively and identifying respectively said initialized ones of said host processor addressable logical data storage vol umes and said physical volumes in which the respective logical data storage volume reside establishing in said control means for use in said listing a plurality of volume control categories including a stack category for indicating erased physical volumes that are to store a plurality of said host processor addressable logical data storage volumes a scratch category for indicating erased physical volumes that are to store a single host processor addressable logical data storage volume physical volumes that are storing one of said host processor addressable logical data storage vol umes in a unitary category and that was previously had a scratch category and physical volumes that are in a partition category that respectively are storing one or more of said a plurality of said host processor addres
53. bsystem to respond to a MOUNT command received from an attached host processor when no volume exists to be mounted to create or establish a volume then mount the volume for responding to the MOUNT command Such volumes can be logical or virtual volumes established in a physical volume i e such as a reel of tape The subsystems manages the logical volumes LV s in relation to the physical volumes using a peripheral data base Each physi cal volume can contain a variable number of LV s For accessing the LV s physical segments are identified in the physical volume preferably using PRV s Each PRV may indicate a boundary between two longitudinally adjacent segments Each constitutes one partition of the physical volume Each partition consists of one or more preferably contiguous segments The LV s are accessible on a random basis Two or more concurrent conflicting access requests for different LV s in the same physical volume are honored by copying one of the LV s to another physical volume Any one of several methods are employed Appending data to an existing LV is monitored and managed to ensure that the data being appended do not unintentionally overwrite data already stored recorded in the physical volume In response to detected possible over writing the current writing is aborted then another LV is selected created for receiving the data and the data are rewritten into the newly selected created It is preferred that
54. cating that first predetermined ones of said VOLSER volume serial numbers in said first predetermined subset respectively identify ones of said host processor addressable logical data storage volumes that are to reside on ones of said first sub plurality of physical volumes wherein said first sub plurality of physical volumes are for storing a plurality of said host processor addressable logical data storage volumes and fourth data means connected to a host processor that is connected to said attachment means for supplying VOLSER data to a host processor all of said VOLSER volume serial numbers as identifying host processor addressable logical data storage volumes whether or not any respective ones of said VOLSER volume serial numbers actual identify a host processor addressable data storage volume such that the volume manager means can respond to said received mount command to create a host processor addressable logical data stor age volume using said VOLSER volume serial num bers in said volume map means 8 In the apparatus set forth in claim 7 further including in combination 30 45 50 55 60 65 fifth data means for actuating said volume manager means to insert into said volume map means identifying data 32 for identifying a second sub plurality of said physical volumes as physical only physical volumes in which each of said physical only physical volumes are to have a visual sensible indication of a res
55. ciated with the source PVP The data volume in the PVO assumes the VOLID of the receiving PVO Subsystem 48 reports the changes to the requesting host processor for updating system volume catalog 50 Referring next to FIG 13 the execution of a locate command is described As background a known Read Block ID command can be used to request the current position on the medium as defined by segment number and logical block number A known Locate Block command can be used position to a specified location on the medium as defined by segment number and logical block number On executing locate commands the segment number is used as a point of locality to start scanning while reading data recorded on the tape for finding the specified logical block It is common practice to use of a Read Block ID command before writing data into a tape volume such as a PVO A similar procedure is used to write data into a LV This procedure is next described The Read Block ID command execution provides location data for finding data to be next written into an LV or PVO The Read Block ID command is used to find and identify the actual location of a logical block after which additional logical blocks are to be recorded The identified existing logical block is a target to which a high speed search can be terminated for quickly positioning the tape for reading or writing appended logical blocks Such Read Block ID command will cause the longitudinal loca tion on tape t
56. cond affinity category to select one of said physical volumes as said selected one physi cal volume having a maximal number of said host processor addressable logical data storage volumes assigned to the mount command identi fied affinity category that has data storage space for said host processor addressable logical data storage volume and that has one of second volume serial numbers 5 546 557 61 program instructions for actuating said control means to mount said selected one physical volume in said addressed media device program instructions for actuating said control means to allocate a predetermined addressable partition of said mounted physical volume for receiving and storing said one host processor addressable logical data storage volume having said addressed volume serial number and then recording in said allocated partition of said selected physical volume said addressed volume serial number such that said allocated partition is addressable as an initialized logical data storage volume by said address volume serial number program instructions for actuating said control means to update said listing for showing that said addressed volume serial number identifies said one logical data storage volume and that said one logical data storage volume resides in said selected physical volume program instructions responsive to said addressed volume serial number being identified in said listing for actu ating said control me
57. d ing in combination said magnetic tape having a plurality of data storage tracks arranged in a serpentine pattern such that a forward tape scanning direction in a first subset of the data storage tracks is from a free end of said magnetic tape to a hub end of said magnetic tape and a forward tape scanning direction in a second subset of the data storage tracks if from said hub end toward said free end said first and second subsets including tracks in a respective half wraps that are interleaved across the magnetic tape laterally to the longitudinal length of the magnetic tape such that scanning the first subset of data storage tracks result in counting said segments in a first direction of count and scanning the second subset of data storage track results in counting said segment in a second direction of count that is reverse to said first direction one of said directions of count being an ascending count 15 In the apparatus set forth in claim 14 further includ ing in combination data base means in said volume manager means for indicating a volume mapping in the apparatus said data base means establishing and maintaining said volume mapping for each host processor addressable logical data storage volume that includes its respective VOLSER volume serial number type of volume as being physical or logical VOLID of the physical volume in which the host processor addres sable logical data storage volume resides status of each said ho
58. d first VOLSER host processor addressable logical data stor age volume said volume moving means mounting said different one of the first sub plurality of said physical volumes on one of said media drives as a second mounted physical volume said attachment means receiving a locate command from one of said attaching host processors for commanding the peripheral controller means to position said mag netic tape medium having said first VOLSER host processor addressable logical data storage volume said peripheral controller means being responsive to said received locate command for actuating said volume manager means to change the displacement location indicated in the locate command to said different dis placement location on said different one of said physi cal volumes and said peripheral controller means actuating the one media drive to position the magnetic tape medium in the second mounted physical data storage volume to said different displacement location 17 In the apparatus set forth in claim 16 further includ ing in combination said attachment means actuating the peripheral controller means for appending data to data stored in an addressed one of host processor addressable logical data storage volumes residing in a predetermined partition of one of the physical volumes with another host processor ad dressable volume in a predetermined one of said par titions such that the addressed host processor address able lo
59. d set of VOLSER volume serial numbers recorded therein that is identical to the respective VOLID volume serial number and given predetermined ones of said received mount com mands indicating respective ones of said VOLID iden tical VOLSER volume serial numbers such that said physical volumes having a VOLID in said first sub plurality of physical volumes are addressable by said apparatus but not addressable by said host processor 6 In the apparatus set forth in claim 5 further including in combination each of said physical volumes for movably mounting a data storage medium each of said media drives having medium displacement indicating means for indicating displacement of said data storage medium of a physical volume mounted therein from a medium reference position of the data storage medium in each said media drive for indicating displacement of the data storage medium from said reference position said peripheral controller means having means for detect ing and indicating a block ID and a first displacement location from said medium reference position of a first one of the host processor addressable logical data storage volumes having a first VOLSER recorded on said mounted medium and being connected to the medium displacement indicating means for reading and storing the block ID and said first displacement location and means for supplying said block ID said first displacement location of said first one of the host process
60. d third volume serial number identified host processor addres sable logical data storage volumes is identified by said second addressed volume serial number if said checking shows that no initialized host proces sor addressable logical data storage volume is iden tified by said second addressed volume serial num ber then selecting and mounting in said addressed media device a predetermined one of said scratch physical volumes then recording on said mounted predetermined one of said scratch physical volumes said second volume serial number allocating the entirety of said mounted 5 546 557 43 predetermined one of said scratch physical volumes for said host processor addressable logical data stor age volume and then identifying said predetermined one of said scratch physical volumes using said second addressed volume serial number if said checking shows that an initialized host proces sor addressable logical data storage volume is iden tified by said second addressed volume serial num ber then selecting and mounting in said addressed media device one of said physical volumes identified in said listing as storing said one host processor addressable logical data storage volume residing on said selected one physical volume and command rejecting only those received mount commands not identifying any volume serial number in said first second or third sets of volume serial numbers 36 The method set forth in claim 34 furt
61. d writing said volume map means having entry means for indicating that first and second host processor addressable logical data storage volumes reside in a first one of said physical volumes said volume manager means for actuating said volume moving means for mounting said first one of said physical volumes in a first one of said media drives for enabling a current access to said first host processor addressable logical data storage volume said volume manager means responding to a second received mount command for mounting said second host processor addressable logical data storage vol ume to identify that said mount command requires access to said first one of said physical volumes said volume manager means having hold means responsive to a current access to of said first one of said host processor addressable logical data storage volume to hold response to said second received mount command until said current access completes said volume moving means mounting a second physical volume on a second media drive completion means in the peripheral controller means for detecting and indicating completion of said current access and said volume manager means having conflict means con nected to said completion means for responding to said hold means and to completion of said current access to access said first one of said mounted first physical volumes to copy said first host processor addressable logical data storage volume from said first p
62. data storage tracks arranged in a serpentine pattern such that a forward tape scanning direction in a first subset of the data storage tracks is from a free end of said magnetic tape to a hub end of said magnetic tape and a forward tape scanning direction in a second subset of the data storage tracks if from said hub end toward said free end said first and second subsets including tracks in a respective half wraps that are inter leaved across the magnetic tape laterally to the longitudinal length of the magnetic tape including the steps in said control means clustering a plurality of said segments into media device addressable partitions assigning predetermined ones of said host processor ad dressable logical data storage volumes to respective predetermined ones of said partitions in said peripheral controller means counting said seg ments in a first direction of count and scanning the second subset of data storage track results in counting said segment in a second direction of count that is reverse to said first direction one of said directions of count being an ascending count 15 20 50 55 60 65 52 in said listing indicating the volume mapping in the apparatus in said listing establishing and maintaining for each host processor addressable logical data stor age volume for indicating said respective volume serial number for each said host processor addressable logical data storage vol ume identi
63. dressed volume serial number if said checking shows that none of said first predetermined ones of said host processor addressable logical data storage vol umes is identified by said addressed volume serial number then selecting one of said physical volumes having one of said second volume serial numbers for identifying in said listing said selected one physical volume by said addressed volume serial number in addition to said one second volume serial number program instructions for actuating said control means to mount said selected one physical volume in said addressed media device program instructions for actuating said control means to allocate a predetermined addressable partition of said selected one physical volume for receiving and storing a host processor addressable logical data storage vol ume having said addressed volume serial number and then recording in said allocated partition of said selected physical volume said addressed volume serial 5 546 557 59 number such that said allocated partition is addressable as an initialized one host processor addressable logical data storage volume by said addressed volume serial number program instructions for actuating said control means to then record in said selected one physical volume an index to said one host processor addressable logical data storage volume that includes an address of said allocated addressable partition whereby said one host processor addressable logica
64. e magnetic data storage tape each of said media drives having medium displacement detecting and indicating means for detecting and indi cating displacement of a medium of a physical volume mounted therein from a beginning of a medium refer ence position as an indicated position of said magnetic data storage tape said peripheral controller means having segment means for indicating a plurality of addressable segments in said magnetic data storage tape said peripheral controller means having means for detect ing and indicating a block ID of data recorded on said mounted medium and being connected to the medium displacement indicating means for reading and storing the block ID and the indicated position from said reference position and means for supplying said block ID said indicated position indicating a first one of the host processor addressable logical data storage vol umes having a first VOLSER to a one of said host processors as a first position reference value in said mounted medium and said second means of said volume manager means having volume assignment means for assigning respective one of said host processor addressable logical data storage volumes to predetermined ones of said segments said volume manager means establishing in said volume map means a volume map of said host processor addressable logical data storage volumes assigned to and identifying said physical volumes in which said assigned host processor addressab
65. e sub system to a host processor a plurality of addressable media devices for removably receiving physi cal volumes of data storage media means connected to the control means and to the media devices for mounting and demounting said physical volumes of data storage media said media devices being connected to the attachment means for exchanging data signals therewith said program product comprising data storage means having machine sensible program instructions includ ing 10 20 25 40 45 50 55 60 65 58 program instructions for establishing a plurality of vol ume serial numbers program instructions for establishing a listing in said control means containing indications of a first set having a plurality of first ones of said volume serial numbers that are to be used only for identifying host processor addressable logical data storage volumes and for establishing a second set of second ones of said volume serial numbers that are to be used only to identify stack ones of said physical volumes in which said host processor addressable logical data storage volumes can reside program instructions for first initializing first predeter mined ones of said host processor addressable logical data storage volumes including first allocating a pre determined partition of predetermined ones of said physical volumes for respective ones of first predeter mined ones of said host processor addressable logical data stora
66. e volume having said addressed volume serial number and then recording in said allocated partition of said selected physical volume said addressed volume serial number such that said allocated parti tion is addressable as an initialized logical data storage volume by said addressed volume serial number then updating said listing for showing that said addressed volume serial number identifies said one logical data storage volume and that said one logical data storage volume resides in said selected physical volume if said addressed volume serial number is identified in said listing then selecting a second one of said physical volumes as a second selected physical volume identified in said listing by said addressed volume serial number for mounting in said addressed media device then mounting said second selected physical volume in said addressed media device and if said checking shows that the addressed serial number is not a volume serial number in said first plurality of serial numbers rejecting the received mount command as not identifying any data storage volume including if said received mount command identifies a volume serial number in said second plurality of volume serial numbers 63 A program product for operating a peripheral data storage sub system programmed control means in the peripheral data storage sub system for controlling its opera tion and attachment means connected to the control means for attaching th
67. ectively identify ones of said host processor addressable logical data storage volumes residing on predetermined ones of said first sub plurality of physical volumes a given plurality of said first sub plurality of physical volumes storing a plurality of said host processor addressable logical data storage volumes and a predetermined plu rality of said VOLSER volume serial numbers not identifying host processor addressable logical data storage volumes and 20 45 50 65 30 first predetermined received ones of said mount command respectively indicating respective ones of said first predetermined set of said VOLSER volume serial num bers 5 In the apparatus set forth in claim 4 further including in combination said volume map means further identifying a second sub plurality of said physical volumes as physical only physical volumes each of said physical only physical volumes having a visual sensible indication of a respective VOLID volume serial number all of said VOLID volume serial numbers being a unique number and different from said first predetermined first VOLSER volume serial numbers said set of said unique VOLSER volume serial numbers having a second predetermined subset of said VOLSER volume serial numbers being identical to said VOLID volume serial numbers for said second sub plurality of physical volumes each of said physical only physical volumes having a VOLSER volume serial number in said secon
68. ent recorded upon receipt of a locate command Each of the PRV s is a fixed position of tape 30 i e fixed with respect to BOP of the tape It is also preferred that each tape drive can locate any partition without using PRV s In any event after executing a locate command a target logical block must be found before writing into a partition supposedly storing the target or addressed logical block In the locate command field 160 contains the command indicator Field 161 contains the device address CP field 163 is always set to zero 0 in a locate command that is accessing any LV In the prior art partitions were not associated with separately addressable host processor logi cal volumes An example is PVO segments can be each a prior art partition or can be grouped into respective prior art partitions Remember that each PVO prior art consists one and only one addressable data storage volume Field 165 contains the PRV or segment number value that is known to the host processor 45 The generation of this value is describer later with respect to execution of a locate command as shown in FIG 13 This value may not be a correct value for the LV being addressed therefore PVM 57 adjusts the command contained value to provide an accurate execution of the received locate command That is host processors 45 believe that each LV is mounted on a different tape reel and that all segment numbers are not from PBOP as in the case of each LV physic
69. fication of the physical volume in which the host processor addressable logical data storage volume resides and the current location of each said physical volume status of each host processor addressable logical data storage volume as to whether or not the host pro cessor addressable logical data storage volume is mounted in an addressed one of said media devices or that a request to mount has been received identifications of the starting and ending segments of the magnetic tape for each said partition in which the host processor addressable logical data storage vol ume resides and a storage location of the identified physical volume whilst the identified physical volume is demounted from said media devices 60 Apparatus for storing data in a data storage sub system peripherally to a host processor including in com bination attachment means for attaching the apparatus to one or more host processors for receiving commands from an attached host processor exchanging data with the attached host processor and for supplying status infor mation to the attached host processor a plurality of host processor addressable media devices in the sub system a plurality of magnetic tape physical volumes in said data storage sub System and respec tively having volume serial numbers each said media device capable of mounting for reading and writing to and from one of said magnetic tape physical volumes each of said magnetic tape physica
70. fications of an addressed one of said media devices an addressed one of said volume serial numbers and one of said affinity categories in said control means checking said listing for determin ing whether or not an initialized one of said host processor addressable logical data storage volumes is identified by said addressed one of said volume serial numbers if said checking shows that no initialized logical data storage volume is identified by said addressed one of said volume serial numbers then if said one of said affinity categories is said first affinity category then selecting as a selected one physical volume one of said physical volumes having a minimal number of said host processor addressable logical data storage volumes assigned to said first affinity category to the mount com mand identified affinity category and one of sec ond volume serial numbers otherwise if said one of said affinity categories is said second affinity category then selecting one of said physical volumes as said selected one physi cal volume having a maximal number of said host processor addressable logical data storage volumes assigned to the mount command identi fied affinity category that has data storage space for said host processor addressable logical data storage volume and that has one of second volume serial numbers mounting said selected one physical volume in said addressed media device then in said control means allocating a
71. for indicating displace ment of said magnetic tape medium of each of said mounted physical volumes from a beginning of a medium reference position that is a beginning of tape immediately adjacent a free end of the magnetic tape medium and remote from a hub end of the magnetic tape medium said peripheral controller means having means for detect ing and indicating a block ID of data recorded on said mounted magnetic tape medium and indicating a dis placement location of said magnetic tape medium from said medium reference position and being connected to the magnetic tape medium displacement indicating means for reading and storing the block ID and said indicated displacement location from said reference position and means for supplying said block ID said indicated displacement location for indicating a first 5 546 557 35 one of the host processor addressable logical data storage volumes having a first VOLSER to one of said host processors as a first position reference value in said mounted magnetic tape medium said peripheral controller means actuating said volume moving means and said media drives to copy said first VOLSER identified host processor addressable logical data storage volume to a different displacement posi tion on a different one of said first sub plurality of said physical volumes said volume manager means receiv ing from said peripheral controller means an indication of said different displacement location for sai
72. ge volumes and establishing addressability of said first predetermined ones of said host processor addressable logical data storage volumes by inserting predetermined respective ones of said volume serial numbers of said first set in said host processor addres sable logical data storage volumes on respective ones of said predetermined ones of said physical volumes said first predetermined ones of said host processor addressable logical data storage volumes being fewer than a number of said established first volume serial numbers program instructions for establishing in said control means a listing said first predetermined ones of said host processor addressable logical data storage vol umes having said first volume serial numbers respec tively and identifying respectively said first predeter mined ones of said host processor addressable logical data storage volumes and said physical volumes in which the respective first predetermined ones of said host processor addressable logical data storage vol umes reside program instructions for actuating said control means to receive a mount command from an attached host pro cessor into said control means that includes addressed of one of said media devices and an addressed volume serial number in said control means checking said listing for determining whether or not a first predetermined one of said host processor addres sable logical data storage volumes is identified by said ad
73. gical data storage volume has a predetermined data storage capacity said peripheral controller means having write means for writing data into said addressed volume and monitoring means in the peripheral controller means for monitoring said medium displacement indicating means for writing data near an end of said predeter mined partition said monitoring responding to said medium displacement indicating means indicating an approach of one end of said predetermined partition to signal the peripheral controller means to stop writing 18 In the apparatus set forth in claim 17 further includ ing in combination said peripheral controller means having means connected to said monitoring means for responding to said approach indication to indicate to the attachment means that the writing is aborted said attachment means responding to said aborted writing to stop all data transfers to the peripheral controller means and to actuate the peripheral controller means to abort the writing and said peripheral controller means having recover means connect to the attachment means for responding to the 5 10 15 25 30 35 40 45 55 36 attachment means for mounting a second logical vol ume for receiving said data being appended in the addressed one of the host processor addressable logical volumes to be stored in said second logical volume 19 In the apparatus set forth in claim 18 further includ ing in combination
74. ginal host processor At step 248 for reestablishing access to the original PVP a no longer busy signal is sent to the original requesting host processor FIG 15 illustrates accessing a target PVP mounted on a DVE via a second PSC Each subsystem 45 may have a plurality of PSC s 53 that have access to the same DVEs Since each PSC 53 may have one or two data flow circuits for processing read and write data signals error detection and correction managing control characters all as known access to a target PVP may involve two PSCs Numeral 250 designates the channel connections for the two PSCs PSC 1 numbered 251 and PSC 2 numbered 252 The PSCs have known inter PSC data connections In the subsystem one DVE may be temporarily assigned to act as a different device address The requesting host processor 45 for a copied LV accesses the copied LV on a target PVP via the PSC 1 connection to PSC 2 using the PSC 2 data flow circuit not shown for accessing a DVE 253 that is mount ing the target PVP hence the copied LV Other known arrangements may also be used FIG 16 shows a host processor software procedure that forces any host processor 45 requesting access to a second LV on a PVP that is currently being access for first LV to command copying of the second LV to another PVP At step 260 PVM 57 detects an access conflict because access to a second LV on a PVP has been received from a host proces sor At step 263 PVM 57 notifies PSC 53
75. gnetic tape 20 or be a PRV such as shown in Milligan et al supra The physical end of volume PEOV indicates the end of the magnetic tape at the hub end portion Included in the prior art usage of magnetic tape 20 is the Milligan et al disclosed PRV s based upon a reel tachometer indication of tape displacement from a tape hub not shown that enables faster access to the data blocks stored recorded in area 24 Such PRV s are also used to define physical segments of magnetic tape 20 Such physical segments are addressable via the reel tachometer counts all as shown in Milligan et al Each s ch segment is bounded by two selected PRV s generated by the reel tachometer As taught by Milligan et al a separate tape displacement measurement system may be used The present invention builds on the teachings of Milligan et al to provide enhanced automatic data storage volume controls using LV s while simulta neously enhancing usage of magnetic tape 20 FIG 4 illustrates in simplified diagrammatic form an exemplary magnetic tape 30 format employing some described aspects of the present invention Such format consists of partitions that are each identifiable by the Mil ligan et al PRV system each partition comprising one or more of the physical segments Each partition other than a later described first or system partition stores i e is addres sable as an LV one logical volume Such partitions are dynamically generated in response to MOUNT c
76. h partition storing an LV as will become more apparent format identification FID 32 is more extensive in informational content than the prior art FID 22 The leader end of FID 32 is termed beginning of partition BOP The informational content of FID 32 includes whether the partitions on magnetic tape are of fixed or variable in length PH 33 is a partition defining header that has information as set forth below The combination of FID 32 and PH 33 completely defines the specific format of magnetic tape 30 FID 32 PH 33 and area 34 constitute a PH 33 partition addressable by subsystem 48 and is not addres sable by a host processor PH 33 preferably includes the information set forth in Table I below TABLEI VOLID of the PVP of Partition 0 PBOP and PEOP PRV s of Partition 1 PBOP and PEOP PRV s for all partitions 2 N EOD End of Data mark LV s for storing user data such as in records numbered 1 N N is a positive integer are in partitions numbered 0 through N where N is a positive integer designation of a last partition created for a last LV in the PVP The second partition numbered 0 consists of partition FID physical block or mark 33A and a data storing area 34 in which an LV resides Areas 334 34 occupy one or more tape segments Similarly a third partition numbered 2 consists of FID 34 and volume area 35 and is longitudinally adjacent the second partition Similarly fourth partition numbered 3 and having
77. he library as a unit The storage location of the cartridges having such an affinity is preferably in close physical association in the library storage compartments It is desired to extend the Kula kowski et al affinity control for better managing logical volumes having such an affinity for enhancing accessing the various logical volumes depending on the nature of the affinity The terms virtual volume and logical volume have been used to denote identifying a portion of a storage medium as an addressable entity Also the term minidisk has been used to mean virtual disk All of this usage has required a manual actuation of the data processing system to 20 35 40 45 50 55 60 65 6 establish each and every such logical volume or disk That is no automatic means have been shown for automatically creating or establishing a logical volume LV or logical disk The DICTIONARY OF COMPUTING IBM Eight Edi tion 1987 pp 276 and 462 464 define some of the terms listed above The term minidisk on page 276 includes the synonym of virtual disk The term virtual disk is defined on page 462 as being either a so called RAM disk in main storage or a logical subdivision of a physical disk storage device that has its own address consecutive storage space for data and an index or description of stored data so that the data can be accessed Again each and every one of such virtual disks are individuall
78. hen two addressable partitions are required for each LV having a VTOC one partition for the VTOC and one partition for the LV In a fixed size PVP each VTOC portion of an LV consists of one segment while the LV portion partition consists of one or more contiguous segments The LV VTOC reduces the time needed to determine volume contents As such each LV VTOC is a backup to directory data stored in a data base containing this information i e avoids a full scan of the tape to reconstruct the directory information Variable length partitions LV s need not reside in con tiguous segments This LV fragmentation on the tape requires a VTOC at the beginning of the volume such as in area 34 for indicating beginnings and ends of each LV fragment The VTOC in this case would be required to identify the partitions in the event that the data base con taining this information was lost i e scanning the tape would not provide reliable results for reconstructing the directory information FIG 5 shows partitions and their relationship to segments In atape having so called serpentine tracks the forward scan direction represented by arrow 311 viz free end toward the hub end in one set of a plurality of tracks 310 tracks extending between BOM and EOM is opposite to the forward direction of scanning indicated by arrow 313 viz from the hub end toward the free end in a second or adjacent set of a like plurality of tracks 312 Each set of tracks such
79. hen recording in said allocated partition of said selected physical volume said addressed volume serial number such that said allo cated partition is addressable as an initialized logical data storage volume by said addressed volume serial number program instructions for actuating said control means to then update said listing for showing that said addressed volume serial number identifies said one logical data storage volume and that said one logical data storage volume resides in said selected physical volume program instructions actuating said programmed con trol means if said addressed volume serial number is identified in said listing then selecting a second one of said physical volumes as a second selected physi 10 15 64 cal volume identified in said listing by said addressed volume serial number for mounting in said addressed media device program instructions for actuating said programmed contro means to then mount said second selected physical volume in said addressed media device and program instructions responding to said checking show ing that the addressed serial number is not a volume serial number in said first plurality of serial numbers for actuating said control means to reject the received mount command as not identifying any data storage volume including if said received mount command identifies a volume serial number in said second plu rality of volume serial numbers
80. her including the Steps establishing a data base in said control means including said listing as a part of said data base in said data base maintaining a status of each of the host processor addressable logical data storage vol umes hereafter data storage volume that indicates whether or not each said data storage volume is mounted in an addressed one of said media devices a request to mount has been received and a location whereat each of said data storage volumes is stored when not mounted in one of said media devices and further maintaining in data base identifications of a physi cal location of each of said allocated partitions for said data storage volumes 37 The method set forth in claim 36 further including the steps maintaining in said data base an indication that first and second data storage volumes reside in a first one of said physical volumes mounting said first one of said physical volumes in a first one of said media devices for enabling a current access to said first data storage volume receiving in the control means from the attachment means a mount command for said second data storage volume to be mounted on a second one of said media devices holding in said control means a response to said received mount command mounting on a second one of said media devices a second physical volume detecting completion of said current access to said first data storage volume copying from said first physical volume to said
81. host processor addressable logical data storage volumes including first allocating a predetermined partition of predetermined ones of said physical volumes for respective ones of said host processor addressable logical data storage volumes and establishing addressability of said host processor addressable logical data storage volumes by inserting respective ones of said volume serial numbers of said first set in said host processor addressable logi cal data storage volumes on respective ones of said physical volumes including initializing fewer of said host processor addressable logical data storage vol umes that the number of said established first volume serial numbers 5 546 557 55 in said control means listing said initialized host proces sor addressable logical data storage volumes having said first volume serial numbers respectively and identifying respectively said initialized ones of said host processor addressable logical data storage vol umes and said physical volumes in which the respective logical data storage volume reside in said listing assigning first and second predetermined ones of said predetermined initialized host processor addressable logical data storage volumes respectively to said first and second affinity categories in said attachment means receiving a mount command from an attached host processor and supplying the received mount command to said control means including in said mount command identi
82. hysical 5 546 557 29 volume to said mounted second physical volume and to update said volume map means for identifying said second addressable host processor addressable logical data storage volume being in said mounted second physical volume and for removing said hold response such that both said first and second addressable logical data storage volumes can be simultaneously accessed 3 In the apparatus set forth in claim 1 further including in combination said volume map means indicating that first and second host processor addressable logical data storage vol umes reside in a first one of said physical volumes said volume manager means mounting said first one of said physical volumes in a first one of said media drives for enabling a current access to said first host proces sor addressable logical data storage volume said volume manager means responding to said received mount command for said second host processor ad dressable logical data storage volume to identify that said mount command requires access to said first one of said physical volumes said volume manager means having hold means responsive to said current access to of said first one of said host processor addressable logical data storage volumes to hold response to said mount command until said current access completes completion means in said peripheral controller means for detecting completion of said current access said attachment means having a plura
83. ing of Tape PEOP Physical End of Partition PEOT Physical End of Tape PRV Physical Reference Value of a tape physical volume used to identify locations of LV s in a PVP This quantity is also term a Physical Reference Index PRI PVO Physical Volume Only one addressable volume as in the prior art PVP Physical Volume Partitioned into logical 5 546 557 3 continued GLOSSARY of ACRONYMS volumes LV Segment The physical portion of a tape that is addressable by a tachometer on a tape drive spool Segment No value that enables addressing a logical volume by segment SEGNO Segment number see Segment No VOLI Contains the VOLID for the PV VOLID Physical Volume Identification VOLSER Volume Identification serial number for a virtual or logical volume BACKGROUND OF THE INVENTION The average size of data sets in most computer or data processing centers is significantly less than the capacity of tape or optical data storing disk volumes Also most pro gramming support for peripheral data storage subsystems does not provide a general solution to storing multiple data sets in the same volume particularly tape volumes Conse quently the potential capacity of tape storage is often not realized because a single small data set is stored in one tape volume leaving the remainder of the volume unused With the advent of automated tape libraries ATL the cost of this unused storage includes not only the
84. ing the data to be next written into the data storage volume After recording the appended data many other operations will occur some of which may cause the LV to be moved from its last accessed position to another PVP or to another location in the same PVP 5 546 557 25 Host processor 45 then needs to access the appended data Host processor 45 first must mount the data storage volume to an addressed DVE using MOUNT command 49 Since the volume being mounted is an LV assume that the LV is on a different PVP and at a different longitudinal position on such different PVP PSC 52 and PVM 57 select the PVP storing the MOUNT command addressed LV for mounting in the addressed DVE the PVP storing the addressed LV At this time PSC 52 has a stored indication not shown generated while executing the previously received MOUNT command 40 for the addressed LV that the mounted volume is an LV This indication directs PSC 52 to actuate PVM 57 for obtaining and generating control information necessary to correctly position the PVP tape in response to any ensuing host processor 45 issued peripheral command In preparation for data processing operations host pro cessor 45 in step 230 issues the Locate Block ID command using the step 227 provided location information all of which is incorrect for the new LV location PSC 52 receives and decodes the step 227 supplied locate block ID com mand Then PSC 52 responds to the stored LV indication to
85. ing the physical volume or by machine sensible positions with or without marks on the medium of such medium For sensing machine sensible positions of a tape physical volume as shown in Milligan et al supra a tachometer of a tape drive that mounts a tape physical volume measures tape displacement of the tape in the tape volume past a transducer for enabling machine sensing the current portion of the tape being scanned by the transducer in the tape drive For interchange of each tape physical volume between diverse tape drives appropriate tape mo tion tolerances are accommodated in defining partitions of each tape A partition is not directly nor explicitly address able by the host processor in a PVP only the LV is addressable GLOSSARY of ACRONYMS ACL Automatic Cartridge Library ACS Automatic Class Selection ATL Automatic Tape Library CAR Concurrent or conflicting Access Requests Category Code assigned to a PV VV or LV defining an or CAT attribute of the respective volume FID Format Identification FSID Format Segment Identification HDR1 Contains the VOLSER the LV in a STACK category PVP or an empty LV HDRI contains a specific code indicating that the volume contains no data JO Input Output LBOP Logical Beginning of Partition LBOT Logical Beginning of Tape LBOV Logical Beginning of a Volume PV VV or LV LEOP Logical End of Partition LV Logical Volume PBOP Physical Beginning of Partition PBOT Physical Beginn
86. ion responding to said approach indication to indicate to the attachment means that the writing is aborted responding in the attachment means to said aborted writ ing to stop all data transfers and to then initiate rewrit ing the data to be appended assigning a second host processor addressable logical data storage volume for storing said data to be appended and storing said data to be appended in said second host processor addressable logical data storage volume 45 The method set forth in claim 43 wherein each of said physical volumes movably mount a data storage medium said storage medium being an elongated flexible magnetic data storage tape each of said media devices having medium displacement detecting and indicating means for detecting and indicating displacement of said tape of a physical volume mounted therein from a medium reference position said detecting and indicating means indicating said displacement in segments of said magnetic tape said seg ments being predetermined longitudinal displacements in each said tape from said medium reference position said longitudinal displacements giving said segments predeter mined sizes respectively said data recorded on the medium arranged in blocks including the steps during said writing measuring displacement of said tape with respect to an end of said addressed partition for generating an approach indication responding to said approach indication to indicate to the att
87. ion subsystem 48 sends a not ready signal to the requesting host processor s At step 242 PVM 57 selects one PVP for each LV to be copied A criterion is that the target PVP for each LV to be copied is that the target PVP has a same or similar category as the LV it is to receive Preference in selecting a target PVP is that the PVP is mounted on one of the DVEs 53 In any event at step 243 PVM 57 effects loading the target PVP s on appropriate DVEs Then at step 244 upon completing queued commands relating thereto the first access to an LV residing on the first PVP is interrupted The LV to be moved are then copied to the respective target PVPs Copying each LV entails assigning the LV to be moved to a partition on the target PVP as described above for creating LVs accessing the respective LV by moving the PVP tape to the LV then coping the LV to the target PVP followed by updating the FIG 7 illustrated data base step 245 to reflect that the moved LV is on the target PVP at the selected starting PRV This procedure is repeated for each LV to be moved Upon completing each move of an LV to a target PVP PSC 52 at step 246 sends a Mount Completed Response to the request ing host processor 45 signifying that access to the requested LV is now available at a DVE 53 mounting the respective target PVP Upon completing copying the LVs access to the LVs follows the procedures described herein Step 247 sends a known LONG BUSY signal to the ori
88. ion is created for an LV in any PVP including the PH 33 partition the peripheral subsystem always formats the beginning of the next partition by writing the following physical blocks in such longitudinally adjacent unassigned segment area 39 immediately adjacent to volume area 38 with an additional FID Mark in a next segment vacant indicating a partition An EOD mark is recorded after the additional FID mark if there are no additional recording on the tape further from the beginning of medium or tape Again note that the marks in the illustrated embodiment are each physical data blocks indicating the respective indicated tape status as end of partition end of medium etc When a subsequent partition is actually created on the next longitudinal segment s the EOD mark physical block is overwritten with the VOLI record physical block for identifying the partition being created The LEOM is written just beyond the hub facing end of the created partition in a next longitudinally adjacent segment not yet a partition as part of creating establishing by formatting segments to be a next partition 5 546 557 13 In the variable logical volume format there is no unused data storage space between longitudinally adjacent parti tions or LV s Modification of a variable length logical volume other than the last logical volume on the physical volume is not permitted By precluding the creation of residual data between the logical volume
89. ion uses the PRVs to indicate media segments One or more segments are combined into a logical volume that is said to occupy one partition on the storage medium i e one partition as that term is used to partition hard disks used with DOS and OS 2 operating systems A proposed Small Computer Standard Interface SCSI standard ANSI document ISO IEC 10288 ANSI X3 131 1992R Nov 16 1992 in pages 190 204 describes partitions on a magnetic tape Such partitions are compa rable to segments described herein i e physical portions of the tape that are addressable by means external to the tape enable the tape to be transported in a high speed positioning operation without contact with the tape Such high speed positioning as taught by Milligan et al supra is preferably a tachometer on a reel mount in a tape drive Section 10 1 3 page 192 of the ANSI document describes a proposed standard for partitions within a volume Partitions sic segments consist of one or more non overlapped tape areas Each partition segment has its own beginning and ending points In each magnetic tape volume one reel of tape every partition has a defined beginning of partition BOP x an early warning position EW x and an end of partition EOP x where x is the partition number The partition segment numbers need not be recorded on the medium Milligan et al do not mention the early warning or end of partition format blocks For intercha
90. ishing in said subsystem a scratch set of a given plurality of third ones of said physical volumes establishing in said data base a third set of volume serial numbers for identifying a third set of said host proces sor addressable logical data storage volumes each of said third set of volume serial numbers for identifying a host processor addressable logical data storage vol ume to reside alone on one of said scratch physical volumes initiating migrating a predetermined one of said host processor addressable logical data storage volumes from the peripheral data storage sub system to said IO station for moving the one category host processor addressable logical data storage volumes outside the peripheral data storage sub system accessing said data base for identifying a transfer physical volume containing said predetermined one host pro cessor addressable local data storage volume selecting a predetermined one of said physical volumes in said third set and mounting the selected physical vol ume in one of said media devices and mounting said transfer physical volume in a second media device copying said predetermined one host processor address able logical data storage volume from said transfer physical volume to said predetermined one physical volume in said third set moving said predetermined one host processor address able physical volume from said first media device to said IO station and updating the data base to show
91. issues a migrate command including a first device address for an LV that is used for migrating a PVO PSC 52 responds to the host processor command that the migration cannot be effected because the volume LV to be migrated is on a shared tape Host processor 45 responds to the message to identify a specific scratch PVO or any PVO of a scratch category in a mount from category command as a target PVO for the LV with a second device address to mount the target PVO This action selects two DVEs and identifies a PVP via PVM 57 searching the FIG 7 illustrated data base having the LV to be migrated and a PVO to receive the LV At step 216 the identified PVP and PVO are mounted to the respective addressed DVEs Step 217 copies the LV from the mounted PVP to the mounted PVO Then the mounted PVO is ejected 10 20 25 30 35 45 50 55 65 24 from the library via IO station 55 The mounted PVP may remain mounted until its addressed DVE is needed for another tape Step 218 is skipped Step 209 updates the data base by selecting the LV entry VOLSER for deleting the VOLID entry and adjusting the pointers to shorted the linked list of the source PVP The subsystem 48 machine opera tions are initiated and controlled by PSC 52 and PVM 57 then proceeds to other activities via exit 210 Remember that the PRV s of the LV are maintained to be correct on the migrating PVO The VOLSER of the migrated LV is made available i e disasso
92. ject means in the volume manager means for identifying ejectable ones of said physical volumes as migrate volumes media storage means connected to said volume moving means for yielding and receiving said migrate volumes for transport to and from the respective media drives an IO station in the media storage means for yielding and receiving said migrate volumes to and from said vol ume moving means and having a manual port for manually receiving and yielding said migrate volumes said peripheral controller means having migrate initiating means for actuating said volume manager means to migrate an addressed one of said host processor ad dressable logical data storage volumes that resides in a given one of said physical volumes said addressed one of said host processor addressable logical data storage volumes being a certain logical volume said volume manager means having migrate controlling means connected to said migrate initiating means for accessing said data base means for identifying said certain logical volume as being stored in first one of said physical volumes and said migrate controlling means responding to the request to migrate initiating means indicating that said certain logical volume is to be migrated for first selecting a given one of said migrate volumes as a selected migrate volume and then actuating the peripheral controller means to move said certain logical volume from said first one of said physical volumes to said
93. l data storage volume is initialized program instructions for actuating said control means to then update said listing for showing that said addressed volume serial number identifies said one logical data storage volume and that said one logical data storage volume resides in said selected physical volume program instructions for actuating said control means if said addressed volume serial number is identified in said listing to then select a second one of said physical volumes identified in said listing by said addressed volume serial number for mounting in said addressed media device program instructions for actuating said control means to then mount said first selected physical volume in said addressed media device as being said logical data storage volume and program instructions responsive to said checking showing that the addressed volume serial number is not a volume serial number in said first plurality of serial numbers then actuating said control means to reject the received mount command as not identifying any one of said host processor addressable logical data storage volumes including if said received mount command identifies a volume serial number in said second plu rality of volume serial numbers 64 A program product having program instructions for operating peripheral data storage sub system grammed control means in the peripheral data storage sub system for controlling its operation and attachment me
94. l or virtual volumes Step 10 a manual step requires that the size of the volume and other desired characteristics and attributes be defined in computer readable form such as in a unit record card terminal and the like This step is like creating a partition on a hard disk of a personal computer or a mini disk in a data processing environment The manual step 12 is the manually actuated inputting of volume attributes and a command to create or establish a volume Such creation in data processing environments include a system generation SYSGEN step for adding a tape drive disk drive or other volume fixed in the drive to the data processing installa tion SYSGEN is a known procedure that is usually effected in slow periods of processing for avoiding unintended interference with usual data processing activities SYSGEN enables a terminal to identify one at a type peripheral equipment to host processors and the like The term SYS GEN means system generation Once the data storage volume is created established in the data processor auto matic step 13 allocates data storage space to the created established volume The documents incorporated by refer ence illustrate such automatic allocation procedures In accordance with one aspect of the present invention FIG 2 illustrates automatic creation establishment of logical data storing volumes Included in the automatic creation establishment of a data storing volume is an automatic a
95. l volumes having a magnetic tape record medium a plurality host processor addressable logical data storage volumes residing in predetermined ones of said mag netic tape physical volumes volume moving means for inserting and removing said magnetic tape physical volumes into and from said media devices volume manager means connected to the attachment means for receiving mount commands from the attached host processor said mount commands includ ing an address of one of said media devices and one of said volume serial numbers of a predetermined one of said host processor addressable logical data storage volumes to be mounted on said addressed media device said predetermined one of said host processor addressable logical data storage volumes being a mount command addressed host processor addressable logical data storage volume peripheral controller means having multi path data flow means connected to the attachment means and to the media devices for processing digital signals between said attachment means and said media devices volume map means connected to the volume manager means for storing identifications of said volume serial numbers and indications of which of said physical volumes contain said host processor addressable logi cal data storage volumes respectively said volume manager means responding to each of said received mount commands for examining said volume 5 546 557 53 map means for identifying one of said mag
96. le logical data stor age volumes respectively reside said assignment 5 546 557 33 means including means for assigning one of said host processor addressable logical data storage volume to a plurality of contiguous ones of said segments 11 The apparatus set forth in claim 10 further including in combination partition means in the volume manager means for clus tering a plurality of contiguous ones of said segments into respective media drive addressable partitions and said volume assignment means being connected to the partition means for assigning said host processor ad dressable logical data storage volumes to predeter mined respective ones of said partitions 12 In the apparatus set forth in claim 11 further includ ing in combination said partition means clustering a predetermined number of said segments in respective ones of said partitions in a predetermined one of said physical volumes 13 In the apparatus set forth in claim 11 further includ ing in combination said partition means clustering a variable number of said segments in predetermined ones of said partitions respectively such that said partitions in each said physical volume have a different number of said seg ments such that said assigned host processor address able logical data storage volumes in each of said pre determined ones of the physical volumes have different data storage capacities 14 In the apparatus set forth in claim 11 further inclu
97. lity of paths over which data may be transmitted said first media drive being connected to a first one of said paths and said volume manager means having conflict means con nected to said completion means for responding to said hold means and completion of said current access to connect said first media drive to a second one of said paths for enabling access to said second one of said host processor addressable logical data storage vol umes 4 In the apparatus set forth in claim 1 further including in combination said volume map means identifying a first sub plurality of said physical volumes as partitioned physical volumes each of said first sub plurality of said physical volumes having a respective VOLID volume serial number and a visually sensible copy of said respective VOLID volume serial number all of said VOLID volume serial numbers of said first sub plurality of said physical volumes being unique such that none of the VOLID serial numbers in said first sub plurality of physical volumes are duplicated a set of unique VOLSER volume serial numbers for identifying respective ones of said host processor ad dressable logical data storage volumes a first prede termined subset of said VOLSER volume serial num bers being different from any of said VOLID volume serial numbers said volume map means further indicating that first pre determined ones of said VOLSER volume serial num bers in said first predetermined subset resp
98. luding a stack category for indicating erased physical volumes that are to store a plurality of said host processor addressable logical data storage volumes a scratch category for indicating erased physical volumes that are to store a single host processor addressable logical data storage volume physical volumes that are storing one of said host processor addressable logical data storage volumes and that was previously had a scratch category and physical volumes that are in a partition category that respectively are storing one or more of said a plurality of said host processor addressable logical data storage volumes 31 The apparatus set forth in claim 1 further including in combination an automatic media library connected to said peripheral controller means for receiving commands for fetching and storing ones of said physical volumes as com manded ones of said physical volumes said media library having addressable storage compartments for said physical volumes respectively an IO station in the media library said volume moving means being automatic physical volume moving means in said media library and being connected to said IO station for inserting and removing commanded ones of said physical volumes and media storage shelves disposed in a predetermined prox imity to said IO station such that said commanded ones of said physical volumes can be manually transported between said media storage shelves and said IO station 3
99. lume in the control means updating said listing to reflect moving said addressed host processor addressable logical data storage volume to said another physical volume and then in said control means removing said delaying for transferring data from the attachment means to said second physical volume to write said data to be appended in said addressed host processor addressable logical data storage volume residing in said another physical volume 52 The method set forth in claim 51 wherein the segment sizes vary in size between first and second ends of the tape said segment sizes increasing in length in a direction from the first toward the second ends including the step selecting said second partition in said second physical volume to be closer to said second end of the tape than the first partition is from the second end of the tape in said first physical volume 53 The method set forth in claim 51 wherein said physical volumes movably contain data storage tapes each of said addressable partition being identified by physical displacement of the respective partition from a beginning of tape including the steps during said writing measuring displacement of tape with respect to an end of said addressed partition for gen erating an approach indication responding to said approach indication to indicate to the attachment means that the writing is aborted responding in the attachment means to said aborted writ ing to sto
100. m 48 to select a PVP then format one or more segments of the selected PVP to create a partition for receiving the field 65 identified LV may include indications of category affinity expiration date and the like for an LV identified by a VOLSER in the MOUNT message MOUNT message may also indicate any MOUNT from Category command Job Step ID that caused a PVP to be initialized so as to be addressable by a host processor In a preferred form of the invention only PVP s are so initiated no limitation thereto intended 5 546 557 17 FIG 8 illustrates interactive steps used to initialize sub system 48 particularly PVM 57 for automatically creating addressable data storage volumes from stack or scratch volumes that are not yet addressable by host processors 45 The interactively entered VOLSERs and VOLIDs can indi cate categories or affinities Such VOLSERs and VOLIDs may be used in the Gelb et al supra automatic class selection procedures Interactive step 92 identifies to sub system 45 via terminal 59 the PVPs that are not initialized and are to become partitioned PVPs for storing LVs Each PVO is but a single tape volume and is one addressable volume Each PVP is initialized as later described As seen in FIG 9 a range 110 of VOLIDs for PVOs is from zero 0 to 10 1 These PVOs can contain valid user data and are not available for reuse nor are to be converted to stack PVPs erased in their entirety In a practical embodi
101. mal number of said physical volumes and establishing a second one of said affinity categories for clustering said host processor addressable logical data storage volumes having said second one affinity category program instructions for initializing predetermined ones of said host processor addressable logical data storage volumes including first allocating a predetermined par tition of predetermined ones of said physical volumes for respective ones of said host processor addressable logical data storage volumes and establishing addres sability of said host processor addressable logical data storage volumes by inserting respective ones of said volume serial numbers of said first set in said host processor addressable logical data storage volumes on respective ones of said physical volumes including initializing fewer of said host processor addressable logical data storage volumes that the number of said established first volume serial numbers program instructions for identifying in said listing said initialized host processor addressable logical data stor age volumes having said first volume serial numbers respectively and identifying respectively said initial ized ones of said host processor addressable logical data storage volumes and said physical volumes in which the respective logical data storage volume reside program instructions for actuating said control means to assign in said listing first and second predetermined one
102. mber of unallocated segments plus a number of LVs having the same affinity cluster parameter is selected for receiving the LV to be created Therefore the affinity parameter can effect assigning LVs to PVPs by indicating a desired LV pattern of distribution amongst plural PVPs The selected PVP if not already mounted is mounted on the addressed DVE Then at step 145 PVM 57 selects an 10 15 20 25 30 35 45 50 55 65 20 available partition no LV is assigned to an available parti tion i e it is logically empty having a proper number of segments The empty partition is formatted to receive the LV The LV to be established including creating a partition as described later is allocated to unallocated segments Remember that each partition in each PVP is a contiguous set of segments with no unallocated segments residing within a partition At step 146 PVM 57 actuates PSC 52 to record the LV s FID in the first allocated segment for identifying the created partition as the LV having the MOUNT command identified VOLSER and PH 33 is updated to reflect the new partition PVM 57 also writes into the created partition an IBM standard label from register 96 as if the created LV were in fact a PVO physical volume The FIG 7 illustrated data base is then updated by updating the entry for the newly estab lished LV to reflect the LV s association with a PVP enters the VOLID of the PVP into the VOLID field of the entry 72
103. means to move said another physical volume to said IO station and then actuate said volume manager means to update said data base means 25 The apparatus as set forth in claim 11 further includ ing in combination said second means of said volume manager means having first format means for recording in said second physical volume a format identification mark that indicates the second physical volume will receive and store one or more first predetermined host processor addressable logical data storage volumes and said second means of said volume manager means having second format means for recording in respective ones of said partitions that receive and store a respective 5 546 557 39 ones of said first predetermined host processor addres sable logical data storage volumes to record in said respective partitions a format identification that indi cates a respective one of said first predetermined host processor addressable logical data storage volumes 26 The apparatus set forth in claim 11 further including in combination the tape having first and second longitudinal ends said partition means clustering beginning at said first end of said tape and clustering into partitions only contigu ous ones of said segments and creating said partitions beginning at said first end of said tape and proceeding toward said second end of the tape to be contiguous such that segments that are not assigned to any partitions are all loc
104. ment such range of values may be VOLIDs starting at a predetermined value In a library system of media storage means 54 after the subsystem is initialized such identified stack PVP s and scratch PVOs are introduced into the storage means 54 by an IO station 55 FIG 6 ina usual manner That is the VOLID to be used in subsystem 45 for each introduced PVP or PVO is placed on the outside of the tape cartridge reel for human bar code reading While terminal 59 is useful for initializing subsystem 48 to automatically create logical volumes the operator termi nal connected to PVM 57 may be dispensed with if such initialization is handled via a host processor The subsystem initialization function is then managed by host processor software using the stack category and a create logical volume function as shown in FIG 8 but commanded by a host processor rather than using terminal 59 FIG 6 In the host processor commanded subsystem initialization a host processor terminal or system management program not shown receives manual input for enabling initiation of subsystem initialization Host processor 45 sends a sub system initialization command not shown but constructed such as shown in FIG 11 for other commands that indicates the ranges of VOLSER s for the logical volumes the ranges of VOLID s for non partitioned or physical only physical volumes PVOs have a default range of values To assist in the automatic management of the subsystem 48 s
105. migrate volume updating said data base to indicate that said copied first one of said host processor addressable logical data storage volumes resides in said migrate volume and does not reside in said source physical volume and in the control means responding to the updated data base indicating that said one host processor addressable logical data storage volume residing in said migrate volume to migrate the copied host processor address able logical data storage in said migrate volume first media device to said IO station and to update said data base to indicate that said copied host processor addres sable logical data storage volume no longer exists and indicating that the copied host processor addressable logical data storage volume is in said migrate volume and is identifiable by a volume ID of said migrate volume 40 The method set forth in claim 34 including the steps establishing a data base in said control means including said listing as a part of said data base in said data base maintaining a status of each of the physical data storage volumes and each of the host 5 546 557 45 processor addressable logical data storage volumes hereafter data storage volumes that indicates whether or not each said data storage volume is mounted in an addressed one of said media devices a request to mount has been received and a location whereat each of said data storage volumes is stored when not mounted in one of said media de
106. n LV was moved from the scratched partition or the LV was scratched made reusable leaving the parti tion empty and unaddressable by a host processor If the VOLSER has no associated PVP the VOLSER data base entry 72 74 has its VOLID field empty a miss or NO exit of step 124 at step 124 if used Then PVM 57 identifies a PVP on which the VOLSER identified LV may be created If PVM 57 determined at step 124 that the requested VOLSER identifies a LV then the PVP containing the requested LV is identified by reading field VOLID of a data base entry 72 74 The library reel storage compartment is identified by reading field LIB of the host PVP entry 67 69 If the identified PVP is not mounted on the addressed DVE field MOUNT in an entry 67 69 indicates VOLSER is not mounted on any DVE 53 then at step 130 the PVP is moved from the media storage means 54 indicated location of field 5 546 557 19 LIB to the addressed DVE for mounting If the selected PVP is mounted on a DVE other than the addressed DVE indicated in field MOUNT and the PVP is not in use e g an LV is not currently mounted on that tape drive then either the PVP is moved to the addressed DVE or the other DVE is temporarily assigned the addressed DVE address for accessing the selected PVP In any event at step 131 tape 30 is positioned in the DVE to the field 85 indicated starting PRV at which the addressed LV begins i e at PBOP FIG 5 After mounting the selected PV
107. n s field 158 Field 158 may indicate a migration of a physical volume or a logical volume to shelf storage from shelf storage to a library to a different volume category and the like The migrate volume command is typically initiated by a host processor operator via a host processor 45 via terminal 59 or by a volume management program not shown nor described executed in a host processor 45 that is beyond the present description The subsystem procedures for effecting volume migrations is later described with respect to FIG 13 A locate or locate block command for finding block within any of the LV s stored in a PVP is shown Prior art locate commands did not have to accommodate more than one addressable volume in one reel of tape Each LV in a of tape has its own set of block numbers that start at zero 0 and proceed to some positive integral value Further as will become apparent the LV s being portable between any two PVPs and between PVPs and PVOs will reside at diverse longitudinal positions of the different magnetic tapes For using a high speed search the segment size has to be considered for executing the locate command That is the longitudinal extent on tape of segments at the hub end of the tape are shorter than the longitudinal extent on tape of segments at the free or leader end For accurate positioning such segment lengths have to be known irrespective where the LV was first recorded and is curr
108. netic tape physical volumes storing said mount command addressed host processor addressable logical data stor age volume first means in the volume manager means for respond ing to identification of one of said magnetic tape physical volumes storing said mount command addressed host processor addressable logical data storage volume for effecting mounting of one of said magnetic tape physical volumes on said addressed media device and second means in the volume manager means for responding to identification of not any of said mag netic tape physical volumes storing said mount com mand addressed host processor addressable logical data storage volume for selecting a second mag netic tape physical volume volume initialization means in the second means for automatically estab lishing a new host processor addressable logical data storage volume as said host processor ad dressed data storage volume and for mounting said second magnetic tape physical volume in said addressed media device each of said media devices having a magnetic tape medium displacement measuring and indicating means for indicating displacement of said magnetic tape medium of a magnetic tape physical volume from a magnetic tape reference position that is a beginning of tape immediately adjacent a free end of the magnetic tape and remote from a hub end of the magnetic tape said volume moving means moving a first one of said magnetic tape physical volumes to a first one of
109. nge information about which partitions segments are present in a magnetic tape volume may be stored in the volume in a device defined area 5 546 557 7 or such information may be an intrinsic attribute of device implementation What such information consists of is not defined in the SCSI document That is the standard does not address how such partitioning could or should be accom plished The SCSI document does indicate that tape move ment between partitions segments has no stable position i e exact position is not known as the tape transducer and tape are not in contact According to the SCSI document each partition seg ment has logical elements that include host processor initiator elements of data and file marks i e usual tape formatting Each unit of data is stored as a logical block Logical block storage is in accordance with the format being used in the volume entire tape not in logical volumes on the tape A setmark is defined that is a mark superior to file marks i e there may be a plurality of file marks disposed between a pair of spaced apart setmarks in any partition segment The SCSI document does not describe how such partitioning segmentation is to be accomplished nor how to manage a subsystem using such partitioning See Milligan et al supra SUMMARY OF THE INVENTION The present invention being practiced in a data processing system having a peripheral data storage subsystem causes the su
110. nted in said dedicated media device and in said listing updating the listing to reflect that said predetermined one of the host processor addressable logical data storage volumes no longer resided in said first physical volume mounted on said one of said media devices addressed by said attachment means but resides in second physical volume mounted in said dedicated media device 58 The method set forth in claim 34 including the steps in host processors attached to said attachment means creating and maintaining a system volume catalog of said host processor addressable logical data storage volumes that includes a plurality of said volume serial numbers for said host processor addressable logical data storage volumes including volume serial numbers that identify no initialized host processor addressable logical data storage volumes in the peripheral data storage subsystem selecting said maintained serial numbers in said system volume catalog to implicitly indicate predetermined categories of said host proces sor addressable logical data storage volumes 59 The method set forth in claim 34 wherein each said physical volume has a relatively movable magnetic tape each said media devices having tape displacement measur ing means that measure reel rotations for indicating tape displacement each tape having segments identifiable by said tape displacement measuring means said magnetic tape having a plurality of longitudinally extending
111. o be precisely located as to a PRV then finding the desired logical position within an LV This location information is given to the host processor 45 for storage Host processor 45 later may have the LV mounted on an addressed DVE Host processor 45 then issues the later described Locate Block ID command for positioning the tape to the location indicated by the Read Block ID executed command If the LV is copied to another PVP before the mount then such LV is usually recorded at a different longitudinal position on the another PVP Such change invalidates the Read Block ID generated location informa tion Since it is desired to insulate the host processor from the effects of such LV location changes the execution of the Locate Block ID command will accommodate the location changes Remember that the host processor 45 is treating the LV as a real data storage volume Returning now to the Read Block ID command execution at step 225 the host processor 45 issues the Read Block ID command as a preparatory action for recording data in the data volume whether an LV or PVO Subsystem 48 executes the Read Block ID command to develop and collect location information Then in step 226 subsystem 48 PSC 52 effects command execution and reporting in a usual manner sends the developed location information as listed above to the host processor 45 In step 227 host processor stores the Read Block ID provided location information for later quickly access
112. o called buffered log data a known collection of status information in IBM peripheral data storage subsystems of subsystem 48 is modified to allow the inclusion of a VOLID in the data This inclusion enables the VOLID of the PVPs that are not separately addressable by a host processor because the VOLID s are not known to such host processors to be given to the host processors for inclusion in performance and error statistics associated with the PVPs Additionally it allows subsystem 48 to present physical volume performance and error statistics to any host processor statistics for any vol ume physical or logical in an unsolicited manner including statistics generated as the results of subsystem copying of logical volumes for moving such logical volumes to a different PVP Interactive step 94 identifies to subsystem 45 range 111 of PVPs as being from 10K to 100K 1 When introduced into the media storage means 54 such PVPs contain no data before nor after the below described initialization A MOUNT command for mounting an LV must be received before any PVP can store data The actual VOLIDs have unique identification such as starting with any selected information pattern Each unformatted PVP that becomes a PVP has no change in VOLID Similarly interactive step 95 identifies to subsystem 45 range 112 of VOLSERs to be used for identifying LVs as being 100K and above Each actual VOLSER or VOLID may have an alphanumeric content 20
113. ock and identification of said mounted physical medium to the attachment means 47 The method set forth in claim 46 including the steps in said control means creating each one of said partitions as an integral number of contiguous ones of said segments recording in said physical volume a format identification mark that identifies that the physical volume will receive and store one or more first predetermined host processor addressable logical data storage vol umes including indicating that each one of said parti tions and a location of said partitions as indicated in segments and recording in respective ones of said partitions that receive and store respective ones of said first predetermined host processor addressable logical data storage vol umes to record in said respective partitions a format identification mark that indicates a respective one of said first predetermined host processor addressable logical data storage volumes 48 The method set forth in claim 46 including the steps in said control means clustering a plurality of said segments into said media device addressable partitions respectively and in said control means assigning predetermined ones of said host processor addressable logical data storage volumes to contiguous ones of said partitions on said magnetic tape 49 The method set forth in claim 48 including the steps in said control means clustering a fixed number of said segments in each of s
114. of said volume serial numbers of said first set in said host processor addressable logical data storage volumes on respective ones of said pre determined ones of said physical volumes said first predetermined ones of said host processor addressable logical data storage volumes being fewer than a num ber of said established first volume serial numbers in said control means listing said first predetermined ones of said host processor addressable logical data storage volumes having said first volume serial numbers respectively and identifying respectively said first predetermined ones of said host processor addressable logical data storage volumes and said physical volumes in which the respective first predetermined ones of said host processor addressable logical data storage vol umes reside receiving a mount command from an attached host pro cessor into said control means that includes an addressed of one of said media devices and an addressed volume serial number in said control means checking said listing for determining whether or not a first predetermined one of said host processor addres sable logical data storage volumes is identified by said addressed volume serial number if said checking shows that none of said first predetermined ones of said host processor addressable logical data storage vol umes is identified by said addressed volume serial number then selecting one of said physical volumes having one of said second v
115. olume serial numbers said volume map means further indicating that first pre determined ones of said VOLSER volume serial num bers in said first predetermined subset respectively identify ones of said host processor addressable logical data storage volumes residing on predetermined ones of said first sub plurality of physical volumes a given plurality of said first sub plurality of physical volumes storing a plurality of said host processor addressable logical data storage volumes and a predetermined plu rality of said VOLSER volume serial numbers not identifying any host processor addressable logical data storage volumes first predetermined received ones of said mount com mands indicating respective ones of said first predeter mined set of said VOLSER volume serial numbers for commanding mounting respective ones of said host processor addressable logical data storage volumes in predetermined addressed ones of said media drives said volume map means responding to said received ones of said mount commands to identify predetermined ones of said physical volumes to be mounted respec tively to said addressed ones of said media drives said volume moving means responding to said volume map means for moving said identified predetermined ones of say physical volumes respectively to said addressed ones of said media drives as mounted physi cal volumes each of said media drives having magnetic tape medium displacement indicating means
116. olume serial numbers for identifying in said listing said selected one physical volume by said addressed volume serial number in addition to said one second volume serial number mounting said selected one physical volume in said addressed media device 10 15 30 50 55 65 42 then allocating a predetermined addressable partition of said selected one physical volume for receiving and storing a host processor addressable logical data stor age volume having said addressed volume serial num ber and then recording in said allocated partition of said selected physical volume said addressed volume serial number such that said allocated partition is addressable as an initialized one host processor addressable logical data storage volume by said addressed volume serial number then recording in said selected one physical volume an index to said one host processor addressable logical data storage volume that includes an address of said allocated addressable partition whereby said one host processor addressable logical data storage volume is initialized then updating said listing for showing that said addressed volume serial number identifies said one logical data storage volume and that said one logical data storage volume resides in said selected physical volume if said addressed volume serial number is identified in said listing then selecting a second one of said physical volumes identified in said listing by said addres
117. ommands received from a host processor as will be further described for storing one host processor addressable LV Such a tape 30 is termed a partitioned or LV data storing magnetic tape hereinafter referred to as a physical volume parti tioned PVP The prior art data storing magnetic tape 20 is termed an unpartitioned or physical only physical vol ume hereinafter termed a physical volume only PVO Unformatted magnetic tapes destined to become partitioned magnetic tapes PVPs are assigned to a stack category These physical volumes are placed in the stack category when they are to be made available to subsystem 48 for stacking one or more logical volumes into one physical volume When a host processor attempts to remove a physi cal volume from this category the library causes any active logical volumes on the physical volume to be copied to another PVP Therefore one of the categories that PVP s are all assigned is the stack category Unformatted magnetic tapes destined to become non partitioned volumes PVO are assigned to an insert category These categories are neces sary as the unpartitioned physical tape volumes PVO must 5 546 557 11 be identified by an VOLID volume identification that is both external visual and internal magnetically recorded Magnetic tape 30 has system reserved area 30 at the free or leader end of the tape Since magnetic tape 30 is divided into addressable partitions eac
118. on using a best fit detector All emulated disk volumes were established by manual actuation of the system before the Clifton et al automated volume selection could be invoked The emulated disk volumes are grouped into so called volume groups Clifton et al grouped virtual volumes into volume groups by user manual selection input to the primary host processor chosen criteria Such criteria are application area common retention period and space allo cation quantities One volume group could not be subordi nated to another volume group best fit volume selection criterion included several volume attributes such as volume expiration date being later than a data set expiration date available free space and the like Once each data set is assigned to a given emulated disk volume allocation and storage activities ensued Gelb et al in U S Pat No 5 018 060 extended the automation of volume selection started by Clifton et al Gelb et al provide for inferred or implicit automatic volume selection based upon three data volume defining class attributes DATA class includes user defined data attributes A STORAGE class defined user inputted perfor mance and other storage related parameters viz capacity access time etc A user defined MANAGEMENT class related to scratching volumes and data sets and the like The three classes are used to select a volume identified in one or more STORAGE groups of volumes A primary purpose of Gelb et al
119. ons FIG 7 illustrates a data base structure that PVM 57 uses to manage the volumes in subsystem 48 Volume map 58 FIG 6 also represents a portion of the subsystem data base The FIG 7 illustration diagrammatically shows a data base organization suitable for PVO PVP and LV s The illus trated data fields in each data entry are exemplary The data base includes definitions for all partitioned physical volumes PVP s including indications of whether fixed size or vari able size partitions are used non partitioned physical vol umes PVO s and logical volumes LV s The data base is logically divided into two portions a PVP portion 65 for physical volumes and an LV portion 66 for logical volumes Three PVP data entries 67 68 and 69 are illustrative of PVP and PVO entries while the entries 72 73 and 74 are illustrative of entries for logical volumes If PVPs and PVOs having diverse data storage capacities reside in the subsystem then the PVP entries may also contain data storage capacity information not shown In each PVP entry VOLID field identifies the physical volume If the LV index field is null then the PVP is empty If the LV index field contains a special character not shown or the VOLID then the physical volume is a PVO The data base can be restricted to describing LV s and PVP s in the latter instance no PVO s are described in the data base For physical volume entry describing a PVP the LV index has a data base poin
120. ons for listing said initialized host pro cessor addressable logical data storage volumes having said first volume serial numbers respectively and identifying respectively said initialized ones of said host processor addressable logical data storage vol umes and said physical volumes in which the respective logical data storage volume reside program instructions for establishing in said control means for use in said listing a plurality of volume control categories including a stack category for indi cating erased physical volumes that are to store a plurality of said host processor addressable logical data storage volumes a scratch category for indicating erased physical volumes that are to store a single host processor addressable logical data storage vol ume physical volumes that are storing one of said host processor addressable logical data storage vol umes in a unitary category and that was previously had a scratch category and physical volumes that are in a partition category that respectively are storing one or more of said a plurality of said host processor addres sable logical data storage volumes that were in said stack category program instructions for actuating said control means via the attachment means for receiving a mount command from an attached host processor into said control means that includes an address of one of said media devices and an addressed volume serial number wherein said addressed volume serial num
121. onstructed in accordance with the present invention FIG 5 illustrates in simplified form the logical elements of a logical volume in the FIG 4 illustrated tape format and the use of physical references for locating and identifying multiple logical volumes on a tape including logical vol umes in a magnetic tape have a so called serpentine track layout FIG 6 is a simplified block diagram of a data processing System of the present invention FIG 7 diagrammatically shows a peripheral data base used in the FIG 6 illustrated data processing system FIG 8 shows a simplified method for initializing the FIG 6 illustrated data processing system FIG 9 diagrammatically shows an exemplary volume serial number VOLSER range of values for use in the FIG 6 illustrated data processing system FIG 10 shows a simplified method for automatically creating or establishing a logical volume LV in a FIG 6 illustrated and initialized data processing system FIG 11 diagrammatically illustrates an exemplary set of peripheral or channel commands for use in the FIG 6 illustrated data processing system FIG 12 illustrates in simplified form exemplary machine operations of the FIG 6 illustrated data processing system for migrating physical and logical volumes between diverse data storage apparatus FIG 13 illustrates locating a host processor addressed block of a logical volume LV recorded in the FIG 4 illustrated magnetic tape FIG 14 illustra
122. or addressable logical data storage volumes having said first VOLSER to a one of said host pro cessors as a first position indicating reference value in said mounted data storage medium said peripheral controller means actuating said volume moving means and said media means to copy said first VOLSER identified host processor addressable logical data storage volume to a second displacement location on a second one of said first sub plurality of said physical volumes said volume manager means receiv ing from said peripheral controller means an indication of said second displacement location for said first VOLSER host processor addressable logical data stor age volume said volume moving means mounting said second one of the first sub plurality of said physical volumes in a second one of said media drives 5 546 557 31 said attachment means receiving a locate command for commanding the peripheral controller means to posi tion said medium having said first VOLSER host processor addressable logical data storage volume said peripheral controller means responsive to said received locate command for actuating the volume manager means to change the physical position indi cated in the locate command to said second physical location on said second one of said first sub plurality of said physical volumes and said peripheral controller means actuating said second one of said media drives to position the medium in the mounted physical dat
123. p all data transfers and to then initiate rewrit ing the data to be appended 10 20 30 35 45 50 55 60 65 50 assigning a second host processor addressable logical data storage volume for storing said data to be appended and storing said data to be appended in said second host processor addressable logical data storage volume 54 The method set forth in claim 34 including the steps in said listing indicating one or more categories for each of said host processor addressable logical data storage volumes in said mount command indicating a category for said mount command identified host processor addressable data storage volume in said category indication indi cating a predetermined attribute of said command iden tified host processor addressable data storage volume in said listing identifying ones of said physical volumes that include a host processor addressable logical data storage volume having said mount command indicated category and for selecting said second physical volume for mounting in said addressed media device and in said listing maintaining indications that including a stack category for indicating erased physical volumes that are to store a plurality of said host processor addressable logical data storage volumes a scratch category for indicating erased physical volumes that are to store a single host processor addressable data stor age volume physical volumes that are storing one
124. pective VOLID volume serial number all of said VOLID volume serial numbers being a unique number said set of unique VOLSER volume serial numbers hav ing a second predetermined subset of said VOLSER volume serial numbers being identical to said VOLID volume serial numbers for said second sub plurality of physical volumes and each of said physical only logical data storage volumes having one of said VOLSER serial numbers of said second predetermined subset recorded therein for machine sensing and that is equal to the VOLID volume serial number of said respective physical only data storage volume 9 In the apparatus set forth in claim 7 further including in combination said initialization means being in one of said host pro cessor means said initialization means for sending an initialization command to said attachment means that contains the data from said initialization means first through fourth data means for actuating the volume manager means to insert said identifying data into said volume map means and said volume manager means having means connected to said attachment means for receiving said initialization command for responding to said initialization com mand for inserting said identifying data into said vol ume map means 10 The apparatus set forth in claim 1 further including in combination each of said physical volumes movably mounting a data storage medium said storage medium being an elon gated flexibl
125. percentage of the volume which is not utilized but also the cost of storing that unused medium in the ATL Tape products and heir associated software support which develop mecha nisms which can fully utilize volume capacities will in general have a significant competitive advantage over com parable products which cannot fully utilize volume capacity One possible mechanism to better utilize the capacity of a tape volume is to store multiple volume images virtual or logical volumes LV on a single physical volume For better utilization of data storage space the data which would have been stored in multiple mostly unused physical vol umes are collected into a single physical volume Such data in accordance with this invention are stored in separately addressable host processor defined logical data storage vol umes Access to the first byte of data in such logical or virtual volumes may be slower than the access to a first byte of data in a single physical volume In the logical volume case the beginning of the logical volume is generally some where away from the normal tape loading point This fact means that before the first byte of data in a logical volume is accessible not only is the physical volume mounted but the logical volume has to be found by moving the tape to place the logical volume at the tape transducer Also con current conflicting access requests to multiple logical vol umes residing on the same tape have to be re
126. physical volumes that includes a maximal number of said host processor addressable logical data storage volumes having said second affinity category for receiving and storing said mount command indicated host processor addressable logical data storage volume 56 The method set forth in claim 34 wherein said peripheral data storage subsystem has an automatic media library said automatic media library being connected to said control means to said media devices and to said attachment means for responding to said control means for fetching and 5 546 557 51 storing ones of said physical volumes as attachment means addressed ones of said host processor addressable logical data storage volumes said automatic media library having addressable storage compartments for said physical vol umes an IO station in the media library and in said automatic media library responding to selecting physical volumes in said control means for transporting ones of said physical volumes between said compart ments said media devices and said IO station 57 The method set forth in claim 34 including the steps providing a dedicated media device that is addressable only by said control means and not by said attachment means copying a predetermined one of the host processor ad dressable logical data storage volumes from a first physical volume mounted on one of said media devices addressed by said attachment means to a second physi cal volume mou
127. predetermined addressable partition of said mounted physical volume for receiving and storing said one host processor ad dressable logical data storage volume having said addressed volume serial number and then recording in said allocated partition of said selected physical volume said addressed volume serial number such that said allocated partition is addressable as an initialized logi cal data storage volume by said address volume serial number then in said listing updating said listing for showing that said addressed volume serial number identifies said one logical data storage volume and that said one logical data storage volume resides in said selected physical volume if said addressed volume serial number is identified in said listing then selecting a second one of said physical volumes identified in said listing by said addressed volume serial number for mounting in said addressed media device 10 15 20 25 30 35 40 45 50 55 65 56 then mounting said second selected physical volume in said addressed media device as being said logical data storage volume and if said checking shows that the addressed serial number is not a volume serial number in said first plurality of serial numbers rejecting the received mount command as not identifying any data storage volume including if said received mount command identifies a volume serial number in said second plurality of volume serial numbers 62
128. rage volume is stored in said respective physical volume and in each of said second portion entries in one of said linked lists inserting an identification of the VOLID of a respective one of said physical volumes storing a respective host processor addressable logical data stor age volume identified in said each second portion entry 41 The method set forth in claim 34 wherein the periph eral data storage system includes media storage means hav ing physical volume moving means for yielding and receiv ing said physical volumes for transport between the respective media devices and physical volume storage com partments of said media storage means said media storage means having an IO station connected to the physical volume moving means for yielding and receiving magnetic data storage volumes to and from the media storage means and having a manual input and manual output port the method further including the steps identifying predetermined ones of said physical volumes as ejectable physical volumes and identifying all other physical volumes excepting said ejectable physical volumes as non ejectable physical volumes initiating migration an addressed one of said host proces sor addressable logical data storage volumes to said manual output port identifying said addressed one of said host processor addressable logical data storage volumes as a certain volume accessing said listing for indicating that said certain volume is stored in fir
129. rate command requires two device addresses in field 156 As an alternate to two device addresses an ATL DVE 534A dedi cated to use with intra library ATL copying is provided Only PVM 57 can command PSC 52 to select and use the ATL DVE dedicated device In an alternate arrangement the device address in the migrate command is the source PVP while the ATL DVE always mounts the PVP to receive an LV from the command addressed DVE A second alternate is to enable PVM 57 to select one of the host processor devices via PSC 52 as a target device Such PVP mounting in a DVE is represented in the drawing by step 216 Such PVP mounting includes adding the LV to be moved to the target or LV receiving PVP At step 217 the data are moved from the PVP in the addressed DVE to the target PVP Since multiple LV s may be moved PVM at step 218 checks for completion of the consolidation of multiple LVs into one PVP For multiple LV s being moved the PVP mounting step 215 is repeated to ensure correct PVP s are mounted in the addressed and target DVEs Remember that such PVP migration only occurs if the shelf and library are tightly coupled in control One LV can be migrated to shelf at a time In the preferred embodiment the LV receives the VOLID of a PVO during the migration The original VOLSER becomes disassociated from any PVP Selecting two DVEs to migrate one LV can be a two step process executed as step 215 for addressing two DVEs A host processor 45
130. rse physical media tape formats usable for such logical volumes data base control of the logical volumes and volume creation processing The physical volume in which one or more logical volumes reside is not host processor addressable Some physical volumes are ejectable from the data storage subsystem The physical volumes storing the logical vol umes are not ejectable To eject a logical volume it is copied from the storing physical volume to an ejectable physical volume 65 Claims 11 Drawing Sheets 16 17 MANUALLY DEFINE A DATA STORAGE VOLUME AUTOMATICALLY REQUEST MOUNT OF DEFINED DATA STORAGE VOLUME AUTOMATICALLY ESTABLISH DEFINED DATA STORAGE VOLUME AUTOMATICALLY ALLOCATE DATA STORAGE SPACE IN A VOLUME AND STORE DATA U S Patent Aug 13 1996 Sheet 1 of 11 5 546 557 FIG 1 PRIOR ART 10 12 13 AUTOMATICALLY MANUALLY DEFINE MANUALLY ALLOCATE DATA A DATA STORAGE SYSTEM TO STORAGE SPACE VOLUME ESTABLISH VOLUME IN A VOLUME AND STORE DATA 15 16 17 AUTOMATICALLY AUTOMATICALLY MANUALLY DEFINE REQUEST MOUNT ESTABLISH A DATA STORAGE VOLUME OF DEFINED DATA DEFINED DATA STORAGE VOLUME STORAGE VOLUME AUTOMATICALLY ALLOCATE DATA STORAGE SPACE IN A VOLUME AND STORE DATA U S Patent Aug 13 1996 Sheet 2 of 11 5 546 557 FIG 3 PRIOR ART BOV LBOV LEOV PEOV BOV BEGINNING OF VOLUME LBOV LOGICAL BEGINNING
131. s having machine sensible program instructions includ ing program instructions for establishing a plurality of vol ume serial numbers program instructions for establishing a listing in said control means containing indications of a first set having a plurality of first ones of said volume serial numbers that are to be used only for identifying host processor addressable logical data storage volumes establishing a second set of second ones of said volume serial numbers that are to be used only to identify stack ones of said physical volumes in which said host processor addressable logical data storage volumes can reside program instructions for initializing predetermined ones of said host processor addressable logical data storage volumes including first allocating a predetermined par 20 30 35 40 45 50 55 60 65 62 tition of predetermined ones of said physical volumes for respective ones of said host processor addressable logical data storage volumes and establishing addres sability of said host processor addressable logical data storage volumes by inserting respective ones of said volume serial numbers of said first set in said host processor addressable logical data storage volumes on respective ones of said physical volumes including initializing fewer of said host processor addressable logical data storage volumes that the number of said established first volume serial numbers program instructi
132. s it is possible to read through all tape segments and reliable detect all FID marks without knowledge of the starting and ending seg ment boundaries To improve decrease access times to LV s including the position of a next LV to be created it is advisable to maintain a directory of the starting and ending segment numbers within the library system In either the fixed or variably sized partition tape formats each FID should be long enough to provide a landing zone which can be accessed under worst case inter drive posi tioning tolerances That is the longitudinal extent of each FID should be such that fast positioning using the Milligan et al disclosed PRV s will cause the FID to be found in a first locate block operation as later described The PEOP point must be longitudinally positioned far enough away from its adjacent BOP point to ensure that PEOP is detected under all interchange conditions Such spacing ensures against inad vertent overwrite of user or control blocks upon overwriting a next longitudinally adjacent partition begins Even with the spacing described above each partition s PEOP point is logically coincident with a next partition s PBOP point See the vertical double lines between areas 34 and 35 as the PEOP of partition 0 and PBOP of partition 1 Optionally each LV may have its own volume table of contents VTOC at the beginning free end of a partition Since each VTOC must be updatable and addressable t
133. s of said predetermined initialized host processor addressable logical data storage volumes respectively to said first and second affinity categories program instructions for actuating said control means to receive via said attachment means a mount command from an attached host processor and supplying the received mount command to said control means including in said mount command identifications of an addressed one of said media devices an addressed one of said volume serial numbers and one of said affinity categories program instructions for actuating said control means to check said list for determining whether or not an initialized one of said host processor addressable logi cal data storage volumes is identified by said addressed one of said volume serial numbers program instructions for actuating said control means if said checking shows that no initialized logical data storage volume is identified by said addressed one of said volume serial numbers to check if said one of said affinity categories is said first affinity category to select s a selected one physical volume one of said physical volumes having a minimal number of said host processor addressable logical data storage volumes assigned to said first affinity category to the mount command identified affinity category and one of second volume serial numbers program instructions for otherwise actuating said control means if said one of said affinity categories is said se
134. s recorded in a longitudinally adjacent tape partition In this manner in a same PVP some LV s may have VTOC s while other LV s have no VTOC s Referring next to FIG 6 one or more host processors 45 are connected to attach peripheral data storage subsystem 48 using usual peripheral data channel attaching circuits and cables A MOUNT command 49 can be sent by any of the host processors 45 to peripheral data storage subsystem 48 requesting mounting of a data storage volume Such MOUNT command includes the usual MOUNT command indicator the VOLSER s indicated data storage volumes to be mounted the address es of the tape drive s to mount the respective data storage volumes the category in which the VOLSER s are assigned to any affinity characteristic later described the expiration date EXPIRE of each of the data storage volumes to be mounted and a JOB ID that is a host processor reference In accordance with the present inven tion subsystem 48 responds to the MOUNT command to create establish an LV for each VOLSER identification that does not correspond to any data storage LV established in the subsystem As usual host processors 45 maintain a system volume catalog 50 indexed by VOLSER and having other data relating to the VOLSER including a table of contents expiration date etc as is known In practicing the present invention nothing or a minimal informational content is changed as to maintaining system volume catalog 50 Th
135. said media devices said first one of said magnetic tape physical volumes having a first one of said host processor addressable logical data storage volumes therein having a plurality of data blocks each data block having a block ID said first media device detecting and indicating a given tape displacement location of a given data block having a given block ID said peripheral controller means having location means for reading said given block ID of said given data block on said tape magnetic tape physical volume and addres sable in said first one of said host processor address able logical data storage volumes in said location means supplying said given block ID and said given tape displacement location to said attach ment means for transmittal to one of said host proces 5015 said volume manager means commanding mounting second magnetic tape physical volume in said second media device in said first and second media devices and in said data flow means copying said first host processor address able logical data storage volume from said first mag netic tape physical volume to said second magnetic tape physical volume including recording said first host processor addressable logical data storage vol ume beginning at a new tape displacement location in said second magnetic tape physical volume that is different from said given tape displacement location of said first physical volume locate command means for supplying a host
136. sed volume serial number for mounting in said addressed media device then mounting said first selected physical volume in said addressed media device as being said logical data storage volume and if said checking shows that the addressed volume serial number is not a volume serial number in said first plurality of serial numbers rejecting the received mount command as not identifying any one of said host processor addressable logical data storage vol umes including if said received mount command iden tifies a volume serial number in said second plurality of volume serial numbers 35 The method set forth in claim 34 further including the steps of establishing in said sub system a scratch set of a given plurality of third ones of said physical volumes establishing in said listing a third set of volume serial numbers for identifying a third set of said host proces sor addressable logical data storage volumes each of said third set of volume serial numbers for identifying a host processor addressable logical data storage vol ume to reside alone on one of said scratch physical volumes receiving a second mount command from an attached host processor into said control means that includes an addressed of one of said media devices and a second addressed volume serial number that is one of said third volume serial numbers in said control means checking said listing for determin ing whether or not an initialized one of sai
137. shing a first path from the attachment means to said first media device and connecting said first media device to a second one of said while the first physical volume is mounted in said first media device 39 method set forth in claim 34 wherein the periph eral data storage sub system includes media storage means having physical volume moving means for yielding and receiving said physical volumes for transport between the respective media devices and physical volume storage com partments of said media storage means said media storage means having an IO station connected to the physical volume moving means for yielding and receiving magnetic data storage volumes to and from the media storage means and having a manual input and manual output port the method further including the steps in said data base means identifying first ones of said physical volumes that are other than said stack ones of said physical volumes as ejectable volumes initiating migrating a first one of said host processor addressable logical data storage volumes to said IO station accessing said data base for identifying as a source physical volume which of said stack physical volumes is storing said host processor addressable logical data storage volume selecting and mounting one of said ejectable volumes in one of said media devices as a migrate volume copying said first one of said host processor addressable logical data storage volumes to said
138. solved It is also desired that the host processor and or personnel operating the host processor have no activities that relate to storing a plurality of volumes of data in one physical volume In the prior art manual control is required for creating or establishing a defined or requested data storage volume It is desired to limit the required manual steps to merely defining each desired volume and for inserting scratch physical volumes into an ATL or open shelf storage The benefits of this enhanced capacity utilization without host processor nor personnel involvement greatly simplifies and obviates the need for personal attention to a data storage system However these benefits come at the expense of creating additional problems which must be handled that is 10 15 20 25 45 55 65 4 The volume image is no longer externally identifiable such that some component of the host library system must maintain a mapping of logical volumes to physi cal volumes This mapping information is a critical system assist which must be highly available highly reliable and disaster recoverable Logical volumes in a same mounted physical data storage volume are not concurrently accessible When there are requests to simultaneously mount a plurality of logical volumes stored in a same physical volume either all but one of the mounts must be deferred possibly creating a data processing deadlock An alternative is to move all but one
139. ssignment of a volume serial number VOLSER to the defined data storage volume Both the subsystem and the host processor must have knowledge of such VOLSER s The procedure includes manual step 15 that is substantially the same as manual step 10 i e data storage volume is defined in a host processor and a VOLSER is selected for the defined data storing volume at this point no actual host processor addressable data storing volume exists Instead of manually inserting the definition of the data storage volume all that is required of the user is to automatically step 16 request command a peripheral data storage subsystem to MOUNT the defined VOLSER data storage volume This automatic step is performed in a usual manner in a host processor connected to the peripheral data storage sub system In step 17 the peripheral data storage subsystem automatically responds to the MOUNT request to create establish a data storage volume having the VOLSER assigned for addressing the data storage volume Once the data storage volume has been automatically established automatic step 18 usually performed in a host processor allocates data storage space in the VOLSER data storage volume as performed in the prior art Therefore the attention to details as required in the prior art is removed from manual activity required in the prior art to create establish an addressable data storage volume In a preferred form of the invention the automatically
140. st one of said physical volumes that is a non ejectable physical volume then selecting a given one of said ejectable physical volumes as a migrate volume 10 15 20 25 30 40 45 50 60 46 mounting said migrate volume on a first one of said drives mounting said first one of the physical volumes on a second one of said drives moving said certain volume from said first one of the physical volumes to said migrate volume then updating said listing to show that the certain volume is disassociated from said first one physical volume by deleting a VOLID of said one physical volume from said listing for said certain volume then migrating said migrate volume to said manual output port and updating the listing to indicate said migrate volume and its data content are migrated from the peripheral data storage system 42 The method set forth in claim 34 wherein the periph eral data storage sub system includes media storage means having physical volume moving means for yielding and receiving said physical volumes for transport between the respective media devices and physical volume storage com partments of said media storage means said media storage means having an IO station connected to the physical volume moving means for yielding and receiving magnetic data storage volumes to and from the media storage means and having a manual input and manual output port the method further including the steps establ
141. st processor addressable logical data storage volume as to whether or not the host processor addressable logical data storage volume is mounted in an addressed one of said media drives whether or not that a mount command has been received for each said host processor addressable logical data storage volume identifications of the starting and ending segments of the medium in which the host processor addressable logical data storage volume resides and 5 15 20 45 50 55 60 65 34 a storage location of the VOLID identified physical volume whilst the identified physical volume is demounted 16 In the apparatus set forth in claim 15 further includ ing in combination said volume map means identifying a first sub plurality of said physical volumes as partitioned physical volumes each of said first sub plurality of said physical volumes having a respective VOLID volume serial number and a visually sensible copy of said respective VOLID volume serial number all of said VOLID volume serial numbers of said first sub plurality of said physical volumes being unique such that none of the VOLID serial numbers in said first sub plurality of physical volumes are duplicated a set of unique VOLSER volume serial numbers for identifying respective ones of said host processor ad dressable logical data storage volumes a first prede termined subset of said VOLSER volume serial num bers being different from any of said VOLID v
142. ter to a linked list of VOLSER or LV entries in the LV portion 66 for all LV s residing in the described PVP The available data storage space of an LV occupied PVP can be calculated by reading the linked list of portion 66 for accessing the start and ending PRV for each LV In each PVP entry of portion 65 a category field indicates any category the physical volume is assigned to date time field indicates the date and time of entry of the PVP into the managed subsystem The mount request field indicates whether or not there is an outstanding request to mount the physical volume For a PVO the mount request is for the physical volume while for a PVP the mount request is for an LN residing in the PVP The mount request for each LV to be mounted is also indicated in portion 66 entry Mounted field indicates whether or not the PVP or PVO is mounted on a tape drive and the subsystem address of such tape drive A null mounted field can be used to indicate that the PVP or 10 15 20 25 30 35 40 45 50 55 65 16 PVO is not mounted If the PVP or PVO has an assigned affinity characteristic the affinity field indicates that char acteristic The type field indicates whether the PVP is a fixed sized partitioned or a variable sized partition physical vol ume The library field lib indicates the address at which the physical volume is stored in an automatic library History field may be used to indicate a recent histor
143. tes machine operations of the FIG 6 illustrated data processing system for accommodating con current conflicting requests to a single physical volume for multiple logical volumes recorded or stored therein FIG 15 illustrates in simplified form an alternate to the FIG 14 illustrated accommodation to handling multiple concurrent conflicting access requests to a single physical volume for multiple logical volumes recorded or stored therein FIG 16 illustrates in simplified form machine operations of the FIG 6 illustrated data processing system that include execution of host processor software for handling concurrent conflicting requests to a single physical volume for multiple logical volumes recorded or stored therein FIG 17 illustrates in simplified form machine operation in the FIG 6 illustrated data processing system for append ing data to data stored in a logical volume and for error control as a logical volume becomes full of data 5 546 557 9 FIG 18 diagrammatically illustrates two optical disks in which the present invention is practiced using the FIG 6 illustrated data processing system and the illustrated meth ods and structures shown in FIGS 2 7 12 and 14 17 DETAILED DESCRIPTION Referring now more particularly to the appended drawing like numerals indicate like parts and structural features in the various figures FIG 1 illustrates a prior art method for creating or establishing volumes including logica
144. that said predetermined one of said host processor addressable logical data storage volume is no longer in said peripheral data storage sub system nor said transfer physical volume and that said predetermined one host processor addres sable physical volume is no longer in the peripheral data storage sub system 43 In the method set forth in claim 34 including the 65 Steps appending data to any data stored in an addressed one of host processor addressable logical data storage vol 5 546 557 47 umes residing in a predetermined one of said addres sable partitions in a predetermined one of said physical volumes writing data into said predetermined one of said addres sable partitions for appending data therein and monitoring in the control means whether or not said predetermined one of said addressable partitions is being filled with data for writing data near an end of said predetermined one of said addressable partitions and upon detecting that said addressable partition is almost full of data stopping writing 44 The method set forth in claim 43 wherein said physical volumes movably contain data storage tapes respectively said addressable partitions being identified by a respective physical displacement of the respective partitions from a beginning of tape including the steps during said writing measuring displacement of tape with respect to an end of said addressed partition for gen erating an approach indicat
145. the partition having the LV is indicated in field partition no For example host processor accessible partitions are num bered in each PVP from 0 to N where N is a positive integer indicating the highest numbered existing partition The PH 33 partition is not accessible by a host processor The CAT field contains the category code s appertaining to the iden tified LV Such categories may be the same as the categories for the host PVP no limitation thereto is intended The LV categories can be independent of the PVP categories This latter arrangement enables assigning a first category to an LV such as private division 1 accounting a category showing expiration on Dec 31 1994 for the LV and a second category to the PVP holding the LV such as expires on Jun 15 1999 The cited categories are only exemplary The MOUNT and MOUNT REQ fields respectively indicate the status of the LV as mounted or requested to be mounted Since each PVP may hold a plurality of LV s only one of the LV s may have a mounted status A history field indicates the recent mount history and other usage of the LV The history field may include the information in the Job ID and Date Time fields Such host related information may not be used by the subsystem enabling the entries to be dispensed with The pointers field are the data base pointers creating the linked list Such linking may be either singly or doubly linked The MOUNT message 49 that actuated subsyste
146. ting the recording prevents encountering PEOP The tape device must enforce partition boundary stop recording at PEOP Numeral 284 indicates that the requesting host processor closes the volume and mount another LV before continuing further data processing FIG 18 shows that the logical volume controls of this invention may be practiced at least in part on disk data storage physical volumes such as designated by numerals 300 and 301 The MOUNT message 49 then is applicable to VOLSERs of portable logical data storing volumes i e independent of the physical medium In response to a received MOUNT command 49 PVM 57 creates a new LV such as LV 305 on disk 300 later a second LV 306 on disk 300 is created in response to a second MOUNT command 49 Therefore it is seen that the principles of this invention are applicable to diverse media While the invention has been particularly shown and described with reference to preferred embodiments thereof it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention What is claimed is 1 Apparatus for storing data peripherally to a host pro cessor including in combination attachment means for attaching the apparatus to one or more host processors for receiving commands from an attached host processor exchanging data with the attached host processor and for supplying status infor
147. tion said indicated affinity means indicating that a maximal number of said host processor addressable logical data storage volumes are to reside in a minimal number of said plurality of physical volumes in said set and said volume assignment means selecting one of said plurality of said physical volumes that includes a maximal number of said host processor addressable logical data storage volumes for receiving and storing said mount command indicated host processor addres sable data storage volume 30 The apparatus set forth in claim 1 further including in combination said mount command indicating a category for said mount command identified host processor addressable data storage volume said indication being a volume serial number residing in one of a plurality of ranges of volume serial numbers that respectively indicate said category 20 35 50 55 40 said volume manager means having data base means for maintaining category indications for said host proces sor addressable logical data storage volumes said data base means being connected to said second means and being responsive to said second means for identifying ones of said physical volumes that include a host processor addressable logical data storage vol ume having said mount command indicated category and for indicating to the second means one of said identified physical volumes as said second physical volume and said data base means category indications inc
148. to create data storage space for a data set request allocation This request preferably includes a data set name DSN that is functionally selected to implicitly indicate character of storage and may include category and affinity parameters Machine step 121 receives the DSN and is parameter data for automatically selecting the Gelb et al supra defined classes for facilitating selection of an LV The Gelb et al class selection selects a VOLSER from the LV VOLSERs in range 112 that were inserted into system volume catalog 50 capacity parameters and the like or selects a category containing scratch volumes having desired attributes Host processor 45 then issues a MOUNT command 49 to subsystem 48 whether or not an LV having the desired VOLSER has been created for the host processor Subsystem 48 receives MOUNT command 49 PSC 52 decodes the received MOUNT command then requests PVM 57 to identify which PVP is to be mounted on the DVE indicated in the MOUNT command Then in step 123 PVM 57 searches the FIG 7 illustrated data base for the VOLSER entry for the MOUNT command identified VOLSER s for mounting a PVP on the addressed DVE Numeral 127 indicates exemplary results and search criteria for determin ing a hit VOLSER exists because a data base entry for the command identified VOLSER exists and has a PVP identi fied in field 68 in step 124 i e identify a PVP that either contains the requested VOLSER LV or has a scratched partition a
149. torage volume management including automatic creation establishment of data storage 5 546 557 15 volumes addressable by host processors 45 based upon information contained in system volume catalog 50 Volume map 58 is maintained and stored in a non volatile RAM or data storage disk not shown by PVM 57 Map 58 includes a plurality of entries each entry including a VOLSER field for identifying data storage volumes including all LV s The VOLID of a PVP containing the respective LV is a second field in map 58 Category CAT is a third field Usage of the information in map 58 will become apparent A subsystem data base shown in FIG 7 is maintained for enabling PVM 57 to perform volume creation and management in the subsystem Map 58 may be a separate cached portion of the data base or be three fields in each data base entry as will become apparent Terminal 59 is connected to PVM 57 for initializing PVM 57 as shown in FIG 8 later described As will become apparent host processor 45 can initialize the subsystem for automatic volume creation as well PVM 57 may be either a separate electronic control or an executable computer program in PSC 52 As indicated by the arrow extending from PVM 57 to media storage means 54 PVM 57 prefer ably includes programming that manages media storage means 54 as a library manager Subsystem 48 may include a plurality of PSC s 52 one of which may contain and execute a program effecting the PVM operati
150. toring data identifying the respective physical volume said second portion having a plurality of host processor addressable identifying ones of said entries each of said host processor addressable identifying entries having a volume serial number field VOLSER for storing data that identifies a volume serial number in a range of volume serial numbers automatically assign able to a respective one of said host processor addres sable logical data storage volumes said each said host processor addressable identifying entry including pointer means for pointing to another host processor addressable identifying entry such that linked lists of said host processor addressable identifying entries exist one linked list for each of said first portion entries identifying a respective physical volume storing a host processor addressable logical data storage vol ume said first portion entries including a pointer means point ing to respective ones of said second portion entries for respectively indicating that a host processor address able logical data storage volume is stored in said respective physical volume and each of said second portion entries in a linked list includ ing an identification of the VOLID of a respective one of said physical volumes storing a host processor addressable logical data storage volume identified in said each second portion entry 23 In the apparatus set forth in claim 15 further includ ing in combination e
151. unt 51 The method set forth in claim 48 including the steps appending data to data stored in an addressed one of said host processor addressable logical data storage vol umes residing in a first predetermined one of said partitions of one of the physical volumes writing data into said addressed one of said host proces sor addressable logical data storage volumes in said control means monitoring said displacement of said magnetic tape past a transducer in one of said media devices in said control means responding to said monitoring for indicating writing data near an end of said predetermined partition in said control means responding to said indicating an approach of one end of said predetermined partition to signal the attachment means to abort said writing in said attachment means responding to said aborted writing to stop all data transfers that supply data to be written to said first predetermined host processor ad dressable logical data storage volume in said attachment means initiating rewriting the data to be appended in said control means delaying said rewriting until a partition having a greater data storing capacity is cre ated during said delaying moving the addressed host proces sor addressable logical data storage volume to another physical volume including allocating a greater extent of said tape in a second partition for said first predeter mined host processor addressable logical data storage vo
152. vices dividing said data base into first and second portions in each said portion establishing a plurality of entries for identifying said data storage volumes in said first portion establishing a plurality of physical volume identifying ones of said entries in each of said physical volume identifying entries inserting a volume id VOLID field for storing data identifying the respec tive physical volume in said second portion establishing a plurality of host processor addressable identifying ones of said entries in each of said host processor addressable identifying entries inserting a volume serial number field VOLSER for storing data that identifies a volume serial number in a range of volume serial numbers automatically assignable to a respective one of said host processor addressable identifying logical data storage volumes in said each said host processor addressable identify ing entry inserting pointer means for pointing to another host processor addressable identifying entry such that linked lists of said host processor addressable identifying entries exist establishing one of said linked lists for each of said first portion entries identifying a respective physical volume storing a host processor addressable logical data storage volume in said first portion entries inserting a pointer value pointing to respective ones of said second portion entries for respectively indicating that a host processor addressable logical data sto
153. volumes to said physical volumes said volume manager means responding to each of said received mount commands for examining said volume map means for identifying one of said physical vol umes storing said mount command addressed one of said host processor addressable logical data storage volumes first means in the volume manager means for respond ing to identification of one of said physical volumes storing said mount command addressed one of said host processor addressable logical data storage vol umes for effecting mounting of said one physical volume on said addressed media drive and second means in the volume manager means for responding to identification of none of said physical volumes storing said mount command addressed one of said host processor addressable logical data stor age volumes for selecting a second physical volume volume initialization means in the second means for automatically establishing a new host processor ad dressable logical data storage volume in said second physical volume to be said mount command addressed one of said host processor addressable logical data storage volumes and for actuating said first means to mount said second physical volume in said addressed media drive 2 In the apparatus set forth in claim 1 further including in combination said media drives removably mounting said physical volumes each said media drive removably mounting one of said physical volumes at a time for said reading an
154. y established via a separate manual actuation of the data processing system An example of manually actuating a data processing system for establishing a virtual disk or a minidisk is set forth in the Microsoft MS DOS User s Guide and Refer ence Version 5 0 1991 in pages 149 160 These pages describe a DOS utility program FDISK provides an operator interface for establishing virtual disks That is one physi cal disk is divided into a manually indicated number of partitions each partition being addressable as a separate virtual disk The program is usually used for disks that are not removable Milligan et al in U S Pat No 4 393 445 show generating a physical reference value PRV based upon tape displace ment past a transducer Such PRV s are not separately indicated on the tape Rather spool rotation is used to measure tape displacement for identifying the PRV numbers According to Milligan et al such PRV numbers are usable by a host processing to quickly move to a desired tape displacement position locate recorded data blocks or for error recovery purposes Milligan et al also teach that a PRV is usable for indicating status of a data buffer that stores data to be either written to or has been read from a magnetic tape Such PRV values respectively denote reference points on a magnetic tape that are generated and indicated by means not on the tape i e there are no marks showing such PRV s on the tape The present invent
155. y of the physical volume such as mount history LV additions deletions error conditions and the like Last use field indicates the last time the physical volume was mounted on any tape drive Such last use can be used in connection with volume replacement or ejection algorithms beyond the scope of this description Job ID field may indicate the host processor Job ID asso ciated with the last use In many instances the Job ID is not made available to the subsystem such that the field may be dispensed with or may be nulled Other fields may be added to the PVP PVO entries as desired Portion 66 has a large plurality of LV entries represented by the three entries 72 74 The VOLSER field identifies the LV VOLID field identifies the PVP in which the LV resides If VOLID is null or empty then either the LV has not been created the VOLSER is available for assignment to an LV to be created or that an LV has been scratched The term scratched merely means that the VOLSER does not identify any LV i e the VOLSER is disassociated from any PVP The start PRV and stop PRV fields identify the limits of the VOLSER identified LV more correctly identifies the limits of the partition in which the LV resides The number of segments in a partition holding the LV is an indication of the LV data storage capacity Note that segments have different data storage capacities such that the segment numbers are used in calculating capacity for an LV The number of

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