Characteristics of the ARCBDEXT Exit

The ARCBDEXT installation exit, called during volume backup processing, receives control after DFSMShsm determines that a data set should be backed up but before DFSMShsm backs it up. It also receives control during the backup of individual data sets through the BACKDS and HBACKDS commands and during the backup of migrated data sets.

Start of change A RETAINDAYS value may be returned by the exit for the data set. If a RETAINDAYS value was also specified on the BACKDS/HBACKDS command, then the value specified on the command will be used. If a value greater than 50000 (other than 99999) is returned by the exit, it will be interpreted as 50000. A decimal value of 99999 will indicate that the backup version should never expire. If a value less than zero is returned by the exit, it will be interpreted as zero. End of change

The data set backup exit is called for both system- and non-system-managed data sets that are eligible for backup. A flag (DS1SMSFG) in the data set VTOC entry indicates whether the data set being processed is system-managed.

Note: Do not use the ARCBDEXT installation exit to override management class parameters for a data set. However, you can use it to change the compaction rules for system-managed data sets.

The ARCBDEXT routine must be reentrant.