Changes to CA Disk Backup and Restore (CA Disk) Merge will improve tape utilization

Document ID : KB000027971
Last Modified Date : 14/02/2018
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Merge will deal with tape utilization similar to recent changes in Archive/Backup (PTF QO07324) when Merge PTF QO09812 is GA. These improvements should help CA Disk to more fully utilize Merge output tapes.

IDRC statistics are returned from the Read Buffered Log (RBL) so that we can calculate how much space is left on any particular output tape. To eliminate overhead, small data sets are not considered in the calculation. We can then estimate whether the next Archvol will fit on the current tape. If not, we force a tape swap.

If we determine that there has been an error in reading the RBL, we generate an informational error message and continue to write until we reach the physical end of tape. If the entire current Archvol does not fit, it will be re-written on the next tape; multi-volume Archvols must begin at the beginning of a tape.

If you have a new tape device, it is important that you co-ordinate with your CA representative so that we have the device characteristics for maximum tape utilization. As an example, STK has many new tape devices that require changes to CA Disk software. Check Merge message "ADSDM928 3825" for DEVICE TYPE and estimated CAPACITY of your device.