OAM object collections are always managed by SMS. The ACS routines are executed when the OAM object collection catalog entry is initially defined. The ACS routines provide storage class and management class names that are used as the default storage class and management class assignments recorded in the catalog entry, and the storage group assignment for the collection. OAM uses the storage group assignment to identify the DB2® tables used for storage of the object directory information, for storage of objects in DB2 tables, and to select the file system, optical volume, or tape volume used to store objects that belong to the collection.