Contents

The CA VM:Backup/CA VM:Tape interface enables CA VM:Backup to ask CA VM:Tape to handle CA VM:Backup tape mounts and scratch tape requests.

Setting Up the Interface

The following table explains the four ways to set up CA VM:Backup and CA VM:Tape using this interface.

CA VM: Tape pool selection..

..without the Autopick facility...with the Autopick facility
Your operator mounts scratch tapes from the pool CA VM:Tape selects according to pool assignment rules. CA VM:Tape validates the tapes.The Autopick facility selects tapes from a pool according to pool assignment rules.
If there is no pool assigned, the Autopick facility selects tapes from its general scratch pool.
You allow CA VM:Tape to select the pool based on pool assignment rules. If no pools are defined, CA VM:Tape will request that the operator mount from the general scratch pool.Occasionally, CA VM:Backup may need to remount a previously mounted tape. CA VM:Tape will not select the same NEXT tape, because the PICKLIST has been updated and the previously selected NEXT tape is no longer available for scratch mount usage.
CA VM:Tape reserves an additional drive of each medium and density. CA VM:Tape does this so it can read internal labels of tapes and pass these labels to CA VM:Backup. CA VM:Backup can then update the trailer label on the preceding tape to point to the next tape. If the TAPECHAIN NO configuration file record is used,CA VM:Backup does not update the trailer label. CA VM:Tape reserves the
exact number of tape drives required to perform the job. With the Autopick facility, CA VM:Tape dictates the next tape to be mounted; therefore, CA VM:Tape knows the volser of that next tape.CA VM:Tape is able to pass the volser of the next tape to CA VM:Backup so CA VM:Backup can update the trailer label of the current tape with next-tape information without mounting that next tape. If the TAPECHAIN NO configuration file record is used, CA VM:Backup does not update the trailer label.

Setting up the Interface (Continued)

Specific pools...

... without the Autopick facility... with the Autopick facility
You must define one or more CA VM:Tape scratch pools for use by CA VM:Backup. The names of these pools must match.
(For example, a CA VM:Backup pool referred to as DAILY must be known to CA VM:Tape as DAILY.)
You must define one or more CA VM:Tape scratch pools for use by CA VM:Backup. The names of these pools must match. (For example, a CA VM:Backup pool referred to as DAILY must be known to CA VM:Tape as DAILY.)
CA VM:Backup requests mounts from a specific pool using the POOL option of the MOUNT command.CA VM:Backup requests mounts from a specific pool using the POOL option of the MOUNT Command.
Your operator selects scratch tapes for the requested scratch pool and CA VM:Tape validates them.The Autopick facility selects tapes from the CA VM:Tape scratch pool requested by CA VM:Backup.
CA VM:Tape reserves an additional drive of each medium and density. CA VM:Tape does this so it can read internal labels of tapes and pass these labels to CA VM:Backup.
CA VM:Backup can then update the trailer label on the preceding tape to point to the next tape. If the TAPECHAIN NO configuration file record is used, CA VM:Backup does not update the trailer label
CA VM:Tape reserves the exact number of tape drives required to perform the job. With the Autopick facility, CA VM:Tape dictates the NEXT tape to be mounted; therefore, CA VM:Tape knows the volser of that next tape.CA VM:Tape is able to pass the volser of the next tape to CA VM:Backup so CA VM:Backup can update the trailer label of the current tape with next-tape information without mounting that next tape. If the TAPECHAIN NO configuration file record is used, CA VM:Backup does not update the trailer label.

Using the RESERVE Record and the Autopick Facility

For backup jobs and output tapes for MPC jobs, the following chart describes how drives are obtained and how many drives are obtained depending on whether the VMBACKUP CONFIG file contains a RESERVE ON record or RESERVE OFF record and whether the CA VM:Tape Autopick facility is in use:

When RESERVE ON record is in the VMBACKUP CONFIG file ...

... without the Autopick facility... with the Autopick facility
CA VM:Backup reserves drives before issuing mount requests. When CA VM:Backup requires a tape mount, CA VM:Tape processes the request immediately because the reserved drive is available for CA VM:Backup to use.
Because the Autopick facility is not in use, CA VM:Tape reserves an additional drive of each medium and density for the duration of the job. The job waits until all required drives are reserved, including the additional drives. If you do not want all drives unavailable for the duration of the job or to have the job wait for all drives to be reserved, place a RESERVE OFF record in the VMBACKUP CONFIG file
CA VM:Backup reserves drives before issuing mount requests. When CA VM:Backup requires a tape mount, CA VM:Tape processes the request immediately because the reserved drive is available for CA VM:Backup to use.
Because the Autopick facility is in use, CA VM:Tape reserves the exact number of tape drives required to perform the job.

When RESERVE OFF record is in the VMBACKUP CONFIG file ...

... without the Autopick facility... with the Autopick facility
CA VM:Backup does not reserve drives before issuing mount requests. When CA VM:Backup requires a tape mount, CA VM:Tape queues the request with all other mount requests if tape drives are not available.CA VM:Backup does not reserve drives before issuing mount requests. When CA VM:Backup requires a tape mount, CA VM:Tape queues the request with all other mount requests if tape drives are not available.

How the Interface Works

When using this interface and creating resource pools for CA VM:Backup jobs, the CA VM:Backup Modify Resource Pool system administrator screen gives you the option of allowing CA VM:Tape to select a pool or having CA VM:Backup request a mount from a specific pool. If you choose to have CA VM:Backup specify scratch mounts from a specific pool, CA VM:Backup will specify the POOL option on mount commands for backup jobs. For this reason, the CA VM:Backup scratch tape pool definitions must have the same name on both CA VM:Backup and CA VM:Tape. (For example, the CA VM:Backup resource pool DAILY must be known to CA VM:Tape as DAILY.)

If you use the Autopick facility, do not use the ACCEPT parameter to avoid unnecessary remounting of tapes. Use CA VM:Tape scratch pools assigned only for the use of CA VM:Backup to provide an additional degree of protection for your CA VM:Backup tapes.

Any tape to be used by CA VM:Backup for backup or restore jobs must be in the CA VM:Tape Tape Management Catalog (TMC). If you are running multiple systems and you do not share a common TMC, tapes used by one system are not available on the other systems.

Following is an outline of the events that occur during a backup job and a restore job.

Backup Job Processing

  1. CA VM:Backup verifies that CA VM:Tape is available. CA VM:Tape creates or updates the CA VM:Backup JOBIDS file.
  2. If CA VM:Tape is down, CA VM:Backup queues the job and tries it again every five minutes. You can cancel the job, put it on hold, or reinitialize CA VM:Tape.
  3. If RESERVE is enabled, CA VM:Backup asks CA VM:Tape to reserve the tape drives it requires to complete the job. If the Autopick facility is not implemented, CA VM:Tape reserves an extra drive of each medium and density.
  4. If all tape drives that CA VM:Backup requires are not available, the reserved tape drives are released. CA VM:Backup tries the reservation every five minutes until either all of the tape drives become available or you cancel the job.
  5. CA VM:Tape selects the next tape volume to use in the job:
    1. If the Autopick facility is implemented, CA VM:Tape selects a tape, updates the PICKLIST file, and returns the volser to CA VM:Backup. CA VM:Tape defers the physical tape mount.
    2. If the Autopick facility is not implemented, the operator selects and mounts a scratch volume. CA VM:Tape validates the volser, its status, and pool assignment and returns the volser information to CA VM:Backup.
  6. The tape is mounted:
    1. If the Autopick facility is implemented, the operator mounts the tape selected by the Autopick facility in the previous step.
    2. If the Autopick facility is not implemented, CA VM:Tape detaches the tape drive on which a scratch tape was mounted and attaches it to CA VM:Backup.
  7. The job begins. If additional tape volumes are required, Steps 3 and 4 (above) are repeated as necessary.
  8. CA VM:Backup sends an END JOB signal to CA VM:Tape to release the tape drives.
  9. CA VM:Tape waits for an END JOB signal from CA VM:Backup before cleaning up after the job and making them available for general use. If the CA VM:Backup job does not complete successfully, CA VM:Tape sets the expiration date of the volsers used in the job to make them eligible to be scratched.
    If for some reason CA VM:Tape is unavailable or experiences a problem, CA VM:Backup attempts to send the END JOB signal every five seconds. A message appears giving the operator the option to finish the job or reinitialize CA VM:Tape.

Restore Job Processing

  1. CA VM:Backup verifies that CA VM:Tape is available. CA VM:Tape creates or updates the VMBACKUP JOBIDS file.
    If CA VM:Tape is down, CA VM:Backup queues the job and tries it again every five minutes. You can cancel the job or initialize CA VM:Tape.
  2. CA VM:Backup sends CA VM:Tape a list of volsers to be processed. CA VM:Tape returns a list of densities for the volumes.
    If CA VM:Tape is down, CA VM:Backup waits five minutes and tries the command again.
  3. CA VM:Backup asks CA VM:Tape to mount one of the tapes listed.
    1. All tape copies with the same medium and density are listed. Any of the tapes can satisfy the request.
    2. If none of the tapes listed can be found but another tape copy with a different density is available, the operator can reject the mount request. CA VM:Backup will generate a new mount request of the backup at a different density.
  4. CA VM:Backup detaches the tape drive and makes it available for general use.
  5. CA VM:Tape waits for an END JOB signal from CA VM:Backup before cleaning up after the job.

Restrictions and Requirements

None.

Implementation

  1. Log on to VMTAPE.
  2. Enter the END command to shut down VMTAPE.
  3. Ensure that there is a PRODUCT VMBACKUP VMBACKUP record in the VMTAPE CONFIG file.
    This configuration file record provides CA VM:Tape with the CA VM:Backup service virtual machine user ID. This record activates the CA VM:Tape side of the interface.
    Note: You need to perform Steps 4, 5, and 6 only if you are implementing the interface so that CA VM:Backup specifies the pool to use instead of allowing CA VM:Tape to select the pool named by assignment rules when the scratch pool is configured.
  4. Ensure that there is a POOLASGN record in the VMTAPE CONFIG file. This record specifies the fileid of the file containing the scratch pool assignment rules.
    This file defines the assignment rules for the scratch pools listed. These rules require that the DSN be an asterisk (*), the JOB be the user ID of the CA VM:Backup service virtual machine, and the POOL identifier follow standard naming conventions. For example:
    DSN=*,JOB=VMBACKUP,POOL=DAILY
    
  5. Make sure there is a POOLNAME record in the VMTAPE CONFIG file. This configuration file record specifies the fileid of the file containing the scratch pool definitions. Each scratch pool is defined as a list of volsers belonging to the pool.
    The scratch pool definition file lists the ranges of tapes associated with the scratch pool. For example, the entry would be similar to:
    SCRPOOL=DAILY,RANGE=000001-000100,RANGE=999000-999999
    
  6. Verify that the files specified on the POOLASGN and POOLNAME VMTAPE CONFIG file records represent existing files and that the files contain the correct CA VM:Backup information. If the files do not exist, create them and add the correct CA VM:Backup information.
  7. If the CA VM:Backup volsers are not specified on a SERIES record, you must add the new range to the VMTAPE CONFIG file and run the VMTBUILD utility to add the volser entries to the TMC (CMS TMCs only). Refer to the CA VM:Tape Administration Guide for information about this utility.
  8. If you are using the CA VM:Tape tape positioning user exit (VMTEXIT7), make sure you exclude CA VM:Backup from having its tape positioned.
  9. Enter the PROFILE command to restart VMTAPE.
  10. Enter the #CP DISCONN command to leave VMTAPE running disconnected.
  11. Log on to VMBACKUP.
  12. Make sure neither the VMBEXIT1 nor VMBEXIT5 user exits exist on any accessed minidisk.
  13. Enter the END command to shut down VMBACKUP.
  14. Make sure there is only one PRODUCT VMTAPE VMTAPE record in the VMBACKUP CONFIG file. This configuration file record provides CA VM:Backup with the CA VM:Tape service virtual machine user ID and activates the CA VM:Backup side of the interface.
  15. If you want to disable the RESERVE drive function, add a RESERVE OFF record to the VMBACKUP CONFIG file.
  16. Enter the PROFILE command to restart VMBACKUP.
  17. Enter the #CP DISCONN command to leave VMBACKUP running disconnected.
  18. Log on to VMANAGER.
  19. Enter vmbackup. The System Administrator Main Menu displays.
  20. Select option 3. The Manage Resource Pools screen displays.
  21. Create one or more resource pools for use by your backup jobs following the instructions on the screens. If you allow CA VM:Backup to specify a pool to CA VM:Tape, make sure the resource pool name matches the CA VM:Tape pool name.
  22. Update your job templates to reference the resource pools.