OAM uses some attributes in the management class associated with the object to manage the object. Class transition attributes allow OAM to change the way an object is managed based on its age, its usage, or a predefined periodic function. A class transition is a change in the object's management class or storage class when an event occurs which brings about a change in an object's management criteria or service level. Class transitions occur during an OSMC storage management cycle. Objects requiring class transition use the ACS routines to determine if they should be managed using a different management class or placed at a different level of the storage hierarchy according to a new storage class.
OAM uses the backup attributes of the management class definition to initiate the writing of one or two backup copies of an object. An Auto Backup of 'Y' indicates to OAM that backup copy(s) are required for this object. A Backup Frequency of zero indicates that OAM is to schedule the first backup copy be written at the time the object is initially stored, whereas a non-zero value results in the first backup copy being written during the first storage management cycle after the object has been stored. If two backup copies are desired, specify a value of two or greater in the management class Number of Backup Versions attribute, and specify the SETOSMC statements in your CBROAMxx member of PARMLIB using SECONDBACKUPGROUP to invoke multiple object backup support.
Retention attributes determine the OAM action for expiration of objects. An object can expire automatically based on its age, its usage, or a specific date derived from its management class and an object-specific retention period, if provided. OSMC deletes expired objects from the directory automatically during the storage management cycle with the approval of the auto-delete installation exit.
See z/OS DFSMS OAM Planning, Installation, and Storage Administration Guide for Object Support for a more specific discussion of how to use management classes with objects.