The ARCADEXT installation exit receives control after DFSMShsm confirms that a data set has not been referred to in the number of days specified for the deletion. Checks for other criteria depend on whether the processing is for a level 0 volume or a migration volume.

• If DFSMShsm is retiring data sets on a level 0 volume (DBU processing), ARCADEXT is called before DFSMShsm determines that a current backup version exists. If DFSMShsm is deleting data sets on a level 0 volume (DBA processing), ARCADEXT is called regardless of the expiration date. Although the exit is called before all criteria are met, DFSMShsm does not scratch a data set unless all criteria are met.
• If DFSMShsm is retiring data sets on a migration volume (DBU processing), ARCADEXT is called after DFSMShsm confirms that the data set has either expired or has a backup version.