Aggregate roll-off processing

When a new version of an aggregate group is created, ABARS processing ensures that the number of versions kept does not exceed the amount specified by the NUMBER OF VERSIONS attribute in the management class. If NUMBER OF VERSIONS is exceeded, ABARS rolls off (deletes) the oldest version of that aggregate.

Roll-off processing can occur each time a new ABR record is written to the BCDS. Since ARECOVER creates an ABR record if one does not exist, roll-off processing can occur there as well as during ABACKUP.

Roll-off processing does not occur when the VERIFY parameter is used, because no ABR record is created.

When an aggregate group is removed during roll-off processing, its control file name is located in the catalog and a list of volume serial numbers that the control file resides on is requested. When necessary, the volumes are deleted from the RACF® HSMABR tape volume list. The control file is uncataloged after the volume serial number list has been exhausted. When the file does not exist in the catalog, it is not an error condition, and the ABR record can still be deleted.

If it is active, installation exit ARCTVEXT is called for each volume being processed, indicating to the exit that the volume being expired is an ABARS tape volume.

This process is repeated for the data files and the instruction and activity log files.

After the control file, data files, and instruction and activity log file have been uncataloged and removed from the HSMABR tape volume set, the ABR record is deleted and processing continues with the next ABR record for the group being processed.

Note: It is possible to code SMS ACS routines that direct ABARS files to DASD. If this is done, and the files get migrated to DASD, an HSM DELETE is issued to remove them during roll-off processing. If that delete fails, the file may remain cataloged with no ABR record pointing to it. If this happens, the data set must be manually deleted. See Directing ABARS files to DASD for more information.

You can use the SETSYS ABARSDELETEACTIVITY(Y | N) command to specify whether you want DFSMShsm to automatically delete the ABARS activity log that corresponds to the ABACKUP version being rolled off. The deletion occurs during ABARS roll-off processing or EXPIREBV ABARSVERSIONS processing, and removes the need to manually manage the ABARS activity logs. The default is N, which specifies no automatic deletion.