Migration

For those primary volumes with the MIGRATE space management technique defined on the ADDVOL command, DFSMShsm uses the minimum migration age or the low threshold of occupancy specified for the volume to determine how many data sets are to be migrated. You specify the minimum migration age when you specify the space management technique. During primary volume space management, DFSMShsm uses the priority order determined in the earlier step if thresholds have been specified for the volume. If no thresholds have been specified, DFSMShsm just migrates each candidate data set that it finds on the volume. The end of DFSMShsm’s migration of data sets depends on whether you have specified thresholds of occupancy for the primary volume.

As DFSMShsm examines each data set for migration, it passes control to the data set migration installation exit (ARCMDEXT).