Each object that OAM stores is assigned a storage class and a management class. OAM uses the storage class to determine the initial placement of an object in the OAM object storage hierarchy. OAM also uses the storage class during the OSMC storage management cycle to determine the correct placement of the object when the storage management cycle processes that object. OAM uses the Initial Access Response (IARS) parameter in the storage class to determine if a primary copy of an object is stored on disk (DB2 tables or a file system) or on removable media (optical or tape). If the IARS parameter in the storage class that is assigned to the object is zero, the primary copy of the object is stored on disk. If the IARS parameter is nonzero, the primary object is stored on removable media.

If the IARS parameter specifies that removable media is to be used, the Sustained Data Rate (SDR) parameter of the storage class determines which removable media, optical or tape, is used to accept the primary copy of the object. If the SDR parameter of the storage class is greater than or equal to three (≥3), the primary copy of the object is stored on a tape volume. If the SDR parameter of the storage class is less than three (<3), the primary copy of the object is stored on an optical disk volume.

If the IARS and SDR parameters, taken together, specify either disk or tape media, the OAM Sublevel (OSL) parameter of the storage class determines which disk or tape sublevel is to be used to accept the primary copy of the object. If it has been determined that the primary copy of the object is to be stored on disk, then if the OSL parameter of the storage class equals 1, the primary copy of the object is stored on disk sublevel 1 (DB2 tables), whereas if the OSL parameter of the storage class equals 2, the primary copy of the object is stored on disk sublevel 2 (file system).

Similarly, if it has been determined that the primary copy of the object is to be stored on tape, then if the OSL parameter of the storage class equals 1, the primary copy of the object is stored on a tape sublevel 1 volume. If the OSL parameter of the storage class equals 2, the primary copy of the object is stored on a tape sublevel 2 volume.

Table 1 provides a summary of how the IARS, SDR, and OSL values determine the initial placement of an object in the OAM object storage hierarchy.