Object access

OAM uses the SDR field to determine whether the primary copy of the object should be placed on optical or tape media. An SDR value of 3 or greater places the data on tape media, and a value of 2 or less places the data on optical media.

OAM uses the OSL field to determine (as appropriate):

what disk sublevel the storage class is associated with, or
what tape sublevel the storage class is associated with.

For both disk and tape sublevels, the valid values are 1 or 2; and the default value is 1.

See z/OS DFSMS OAM Planning, Installation, and Storage Administration Guide for Object Support for further information.