Cleanup processing
Cleanup processing is a subset of spill processing. When DFSMShsm does spill processing, it also does cleanup processing. DFSMShsm also does cleanup processing even when spill processing is not enabled.
- Out-of-date VTOC copy data sets created by DFSMShsm releases before Version 2 Release 3.0 and out-of-date VCAT copy data sets
- Unwanted backup versions
When DFSMShsm scratches a VTOC copy data set, it also uncatalogs the data set.
During volume backup processing, DFSMShsm creates a data set (the VTOC copy data set) that contains selected information from the VTOC of the volume that DFSMShsm is backing up. This data set drives the recovery of the volume. DFSMShsm maintains two copies of the VTOC copy data set. When DFSMShsm backs up a volume, the newly created VTOC copy data set becomes the latest VTOC copy data set, and the data set that was previously the latest VTOC copy data set becomes the next latest VTOC copy data set. As a result, these data sets become continually out of date as DFSMShsm keeps backing up the volume. If DFSMShsm encounters any of these out-of-date VTOC or VCAT copy data sets during volume cleanup processing, DFSMShsm scratches them and uncatalogs the VTOC copy data set.
- New backup versions are created and the MCC record for an old backup version is deleted, but the old version is not scratched.
- Use of the BDELETE command. The MCC record for the old backup version is deleted, but the old version is not scratched.
- DFSMShsm selects a DASD daily or spill backup volume.
- No daily backup volume is available. That is, all daily backup volumes assigned to that day in the backup cycle are full, in use, or unavailable.
- No spill backup volume is available. That is, all spill backup volumes are full, in use, or unavailable.
DFSMShsm selects a DASD backup volume
When DFSMShsm selects a non-full, unallocated, DASD daily or spill backup volume, DFSMShsm cleans it up if the volume has not been cleaned up on that day. DFSMShsm cleans up the volume even if the volume is not full.
No daily backup volume available
If you specified SETSYS NOSPILL, DFSMShsm cleans up the full, unallocated, DASD daily backup volumes. DFSMShsm starts with the full, unallocated, DASD daily backup volume that has not been cleaned up in the longest period of time. If the cleaned up DASD daily backup volume is usable, DFSMShsm backs up the level 0 volume to this DASD daily backup volume. Otherwise, DFSMShsm cleans up the full, unallocated, DASD daily backup volume that has not been cleaned up in the next longest period of time. This process continues until a usable DASD daily backup volume is produced or until every full, DASD daily backup volume has been cleaned up on that day. DFSMShsm does not clean up a DASD backup volume more than once a day.
No spill backup volume available
DFSMShsm cleans up the full, unallocated, DASD spill backup volume that has not been cleaned up in the longest period of time. If the cleaned up DASD spill backup volume is usable, DFSMShsm spills the full, DASD daily backup volume to this DASD spill backup volume. Otherwise, DFSMShsm cleans up the full, unallocated, DASD spill backup volume that has not been cleaned up in the next longest period of time. This process continues until a usable DASD spill backup volume is produced or until every full DASD spill backup volume has been cleaned up on that day. DFSMShsm does not clean up a DASD spill backup volume more than once a day.