Configuring HiDRO to allow VM:Tape to manage tapes

Products

• VM:Backup High-Speed Disaster Recovery Option (HiDRO)

Issue/Introduction

Advantages to configuring HiDRO to allow VM:Tape to manage the tapes it uses.

 

Environment

HiDRO r2.8, z/VM 

Resolution

Most customers that use HiDRO with VM:Tape run in this type configuration.

When HiDRO is configured to allow VM:Tape to do all the tape management for its tapes, when a backup job runs HiDRO always asks VM:Tape to select and mount a scratch tape VM:Tape knows to be a valid SCRATCH tape for the HiDRO backup job. For backup jobs, HiDRO will never ask VM:Tape to mount a specific tape volser ... it will always request a SCRATCH tape.

Then only time HiDRO will ask for VM:Tape to mount a specific volser is for restore jobs. HiDRO will request whatever saved tape(s) are needed to complete the restore request.

When backup job tapes expire in the HiDRO catalog and when the CATALOG CONDENSE job runs, expired tapes and the associated catalog records are deleted from the catalog file, and SCRATCH commands are sent to VM:Tape for those tape volumes to set each tape's Retention Period (RETPD) to ZERO, so the next time the VMTAPE SCRATCH command is run the tapes will be marked in the TMC as available SCRATCH tapes that can now be reused for new HiDRO backup jobs.

Also, when HiDRO is configured to always ask VM:Tape for SCRATCH tape the only tapes that will be found in the HiDRO tape pools are the tapes that correspond to current (not expired) HiDRO backups. When the tapes expire, they are deleted from the HiDRO tape pool files because HiDRO is not managing SCRATCH tape selection ... so they are no longer needed.

 

This helps to avoid problems when the HiDRO tape pool files get out of synchronization with the HiDRO catalog file and VM:Tape.