External Data Manager Volumes

External Data Managers, such as DFHSM, DMS/OS and ASM-2, normally have their own retention management mechanisms for tapes created under their control. Rules can be defined to identify those External Data Managers to Control-M/Tape by their program name, job name, data set name, and so on.

If an External Data Manager creates a data set on a scratch volume, this volume is marked as an External Data Manager (EDM) volume. Only an External Data Manager is able to modify EDM volumes.

Note: The concept of External Data Manager volumes is different than the concept of External volumes.

An External Data Manager is allowed to create data sets only on scratch volumes, or volumes that are already marked as EDM volumes (meaning, controlled by a DO RETENTION=EDM statement in Control-M/Tape rules).

Control-M/Tape does not expire a data set or a volume that belongs to an External Data Manager. A special interface exists for the expiration of such volumes. For more information, see the Control-M/Tape chapter of the INCONTROL for z/OS Administrator Guide.

External Data Manager volumes are managed at the volume level and not at the data set level. This means that for a multifile volume, only the first data set is recorded and the rest are ignored. For a multi-volume data set, no volume chaining occurs between different volumes. Each volume shows the same data set as a single volume data set. External Data Manager input operations are ignored by Control-M/Tape. Only the creation of the first file of a volume is recorded.

Note: Abend retention cannot be specified for External Data Manager volumes. If a data set on an External Data Manager volume is not closed normally, the External Data Manager’s retention is performed.