The SMS management class is a list of class transition, backup, and retention attributes. OAM uses management class attributes to manage objects. Every object is assigned a management class when it is created. See Table 1 for management class examples.

Class transition attributes allow OAM to change the way an object is managed based on its age, its usage, or a predefined, periodic calendar event (for example, the 30th day of every month or the first day of the quarter). You cannot use the PERIODIC and TIME SINCE CREATE transition attributes together. Class transitions occur when the OSMC storage management cycle is invoked. For objects requiring class transition, OSMC uses the ACS routines to determine if the objects should be managed using a different management class or if they should be placed at a different level of the storage hierarchy according to a different storage class.

Retention period and expiration attributes of the management class definition determine the OAM action for object expiration. An object can expire automatically based on its age, its usage, or a specific date (derived from its management class or a management-class-approved object-specific retention period, if provided). OSMC uses the auto-delete installation exit to automatically delete expired objects during the storage management cycle. Deletion-hold is used to prevent object deletion while object is in deletion-hold mode. Retention-protection is used to prevent object deletion prior to object's expiration date, and will not allow expiration date to be changed to an earlier date. Deletion-protection is used to prevent object deletion prior to object's expiration date.

Table 1 shows examples for specifying various management class attributes for objects.