Pass 2 of automatic primary space management

During pass 2 of automatic primary space management, DFSMShsm transitions or migrates data sets from the volumes until the space occupied on the volumes is equal to or less than the space specified by the low-threshold attributes contained in the storage groups to which the volumes belong. DFSMShsm migrates only those data sets that have been identified for class transitions, migration, or extent reduction by pass 1 of DFSMShsm-managed volume space management. The following steps are performed in pass 2:

1. Transition data sets that are candidates both for a class transition and extent reduction.
2. Migrate data sets that are candidates both for migration and for extent reduction.
3. Migrate data sets that are candidates only for extent reduction. Schedule a recall for each data set.
4. Transition data sets that are candidates for a class transition in FIFO until the low threshold of occupancy is reached.
5. Migrate data sets in priority order until the low threshold of occupancy is reached.