Parallelism for fast replication data set recovery

The default value for the maximum number of concurrent data set recovery tasks is 2. Two SETSYS keywords are defined to manage the maximum number of tasks for data set recoveries. SETSYS MAXDSRECOVERTASKS is used to specify the maximum number of data set recovery tasks from either DASD or tape. SETSYS MAXDSTAPERECOVERTASKS is used to specify the maximum number of data set recovery tasks specifically from tape. The maximum number of tasks for data set recoveries from tape should be limited to the number of available tape drives.

The following example shows that as many as four tape devices are available to be used for data set recovery.

SETSYS MAXDSTAPERECOVERTASKS(4)

This value must be less than or equal to the maximum number of allowable tasks for data set recoveries from DASD and tape.

To prevent any data set recoveries from tape, specify:

SETSYS MAXDSTAPERECOVERTASKS(0)

To enable up to 32 data set recovery tasks from both disk and tape, specify:

SETSYS MAXDSRECOVERTASKS(32)

Up to 64 tasks can be specified. To maximize throughput for fast replication volume recovery, use the SETSYS DSSXMMODE command to start DFSMSdss in a separate address space to process these requests. For more information about this address space and controlling it, see SETSYS command: Establishing or changing the values of DFSMShsm control parameters and z/OS DFSMShsm Implementation and Customization Guide.