Assignment of class names by using the RESTORE and COPY commands

In an SMS environment, you can use STORCLAS, MGMTCLAS, NULLSTORCLAS, NULLMGMTCLAS, and BYPASSACS keywords with the RESTORE and COPY commands to influence the class names assigned to a data set. Figure 1 shows how these keywords can influence the storage and management class names of the target data set in a restore or copy operation. However, Figure 1 only addresses how the management and storage class names are assigned, not how the storage group name is assigned or how volumes are selected.

Figure 1. DFSMSdss Target Class Selection

The use of MGMTCLAS, STORCLAS, NULLSTORCLAS or NULLMGMTCLAS can result in user-specified classes. Otherwise, the result is source classes.

Notes to Figure 1:

If you specify BYPASSACS, the source data set’s class names or the class names specified with STORCLAS and MGMTCLAS are assigned to the target data set. If you do not specify BYPASSACS, ACS uses the source data set’s class names, or the class names specified with STORCLAS and MGMTCLAS as input to assign the target data set’s class names.
If you specify NULLSTORCLAS, DFSMSdss passes a null storage class to ACS, which selects a storage class for the data set. If you specify NULLSTORCLAS and BYPASSACS together, the data set becomes non-SMS managed.
NULLMGMTCLAS can only be used with SMS-managed data sets. Specifying NULLMGMTCLAS and BYPASSACS together causes the removal of the original management class of the data set.

For information about how target volumes are selected during restore and copy functions, see Managing availability with DFSMSdss.