Using DEBUG to determine the results of DFSMShsm processing without moving data sets

When you first set up DFSMShsm or when you make major changes to the data set selection parameters you have established for it, you may want to know which data sets are selected during volume space management, backup and backup expiration before you allow it to move any data sets. To allow this freedom to test, DFSMShsm provides a DEBUG mode of operation. To run in DEBUG mode, put the following command in the ARCCMDxx member for the DFSMShsm host on which you want to perform the testing:

SETSYS DEBUG

The DEBUG parameter of the SETSYS command permits DFSMShsm to exercise all of its volume backup, dump, and migration functions; but instead of moving or deleting data sets, it merely writes messages to the activity logs to indicate what data set movement or deletion would have occurred. For example, if you are already using DFSMShsm and want to test the effects of the EXPIREBV command, you could issue the SETSYS DEBUG command followed by the EXPIREBV command. DFSMShsm would then write messages to the activity logs, indicating which of your backup versions would have been deleted by the EXPIREBV command.

Issuing the ABACKUP and ARECOVER commands while SETSYS DEBUG is in effect causes the commands to be processed as if the VERIFY parameter were in effect.

If DFSMShsm is stopped when it is running in DEBUG mode, any command requests that have not been processed are lost and are not processed when DFSMShsm is restarted. See Stopping DFSMShsm for a discussion of restarting processing when DFSMShsm is restarted.

The FREQUENCY parameter of the DEFINE DUMPCLASS command is calculated from the last date that the level 0 volume was dumped while DFSMShsm was not in DEBUG mode. This date is not updated when DFSMShsm is running in DEBUG mode because it would prevent volume dumps from processing on schedule when NODEBUG is specified. In DEBUG mode, if the date last dumped is zeros, the FREQUENCY value is not calculated, the level 0 volume is eligible to be dumped, and the date last dumped is not updated. To cancel the effect of the DEBUG parameter of the SETSYS command, you can issue the following command:

SETSYS NODEBUG

However, if the DEBUG parameter is specified in the ARCCMDxx member, you may find it more convenient just to remove the SETSYS DEBUG command from the ARCCMDxx member.