Returning volumes to scratch status

When a volume in a system-managed tape library is returning to scratch status, DFSMSrmm can inform OAM during expiration processing for each volume being changed to scratch status. Return to scratch processing for system-managed volumes can be either synchronous or asynchronous with EXPROC processing. You use the SYSIN EXPROC command EDGSPLCS operand to select the type of processing you want. This function also allows DFSMShsm volumes to return to the scratch category.

If you select asynchronous processing, EDGSPLCS provides for concurrent (parallel) return to scratch processing across libraries through specification of a library name. EDGSPLCS then runs against a single list of volumes generated by RMM and through specification of a library name, the list can be executed multiple times (once for each library). EDGSPLCS also supports concurrent processing of a list of volumes within the same library. EDGSPLCS uses an ENQ to ensure that each volume can be processed by only one instance of EDGSPLCS. In this way, the parallelism is limited to the number of available logical devices and the number of copies of EDGSPLCS that are run.

See Using EDGSPLCS to issue commands to OAM for system-managed volumes for additional information about the EDGSPLCS utility. See EDGSPLCS file for the EDGHSKP utility for information about the EDGSPLCS file for the EDGHSKP utility.

If DFSMSrmm is to return volumes to scratch during EXPROC processing, DFSMSrmm informs OAM to update the TCDB volume status during expiration processing or when the status of a volume is changed using the RMM CHANGEVOLUME subcommand based on the DFSMSrmm EDGRMMxx parmlib OPTION SMSTAPE operand value you specify. See Defining system options: OPTION for information about the DFSMSrmm EDGRMMxx parmlib OPTION SMSTAPE operand.

DFSMSrmm uses the OAM status change exit, CBRUXCUA, to allow DFSMSrmm to be notified of all volume status changes made by others, for example, by ISMF. CBRUXCUA performs this processing:

If a volume is not defined to DFSMSrmm, but is resident in an automated tape library, it is automatically defined to DFSMSrmm. If any errors are encountered, as for cartridge entry processing, the status change is rejected.
If a volume is defined to DFSMSrmm:
- All changes from PRIVATE to SCRATCH status are returned to scratch by any OAM CBRUXCUA request, such as those generated by the EDGSPLCS utility or the ISMF mountable tape volume list processing. Attempts to use OAM CBRUXCUA requests to change the status of a non-scratch-candidate volume to a scratch volume fail with message EDG8194I.
- All changes from PRIVATE to PRIVATE and SCRATCH to SCRATCH are supported to enable OAM to correct discrepancies that might exist with the library manager inventory.
- All changes from SCRATCH to PRIVATE status are accepted. This includes open processing.
- Storage group name changes are recorded in the DFSMSrmm control data set.
- Any change to make TCDB information consistent with DFSMSrmm information is accepted.
The objective is to keep the TCDB and the DFSMSrmm control data set information consistent.

Recommendation: Use the STGADMIN.IGG.LIBRARY resources to protect the new catalog facilities define, alter, and delete of library entries, and volume entries to ensure changes go through the OAM installation exits. Use IDCAMS as an error recovery tool.