MERGE

The MERGE function provides a convenient means to manage the index entries for archived data sets and the volumes that contain them. It helps you to manage the CA Disk archive data sets that have been put on various disk, and tape cartridge.

CA Disk data compression, activated from the DCDATACP sysparm, has no effect on MERGE. Data is handled whether it's compressed or not.

Merge processing has been designed to provide maximum flexibility in managing the archive volumes on disk, tape and other storage media, and at the same time make the best use of the available resources.

Each merge run consolidates the unexpired data sets from one or more tape volumes (or archive data sets on disk) onto new archive volumes, thus freeing up tape volumes, disk space or both. This reduces the space required to store the CA Disk archives, as well as eliminating disk archive data sets with a large percentage of expired data sets.

After the unexpired data sets have been successfully merged forward, the input data sets on disk are deleted, and input tapes are returned to scratch status — disk space is reclaimed and tapes are made available for reuse. All expired CA Disk index entries are dropped from the archives and unexpired entries are updated to reflect their locations on the new tape or disk archives.

Keeping some archives on disk can be desirable, because it maintains easy access to the data through auto-restore processing, without operator intervention.

Disk-to-disk merging provides an efficient means to manage these archives, also without operator intervention.