Place the journal on a different volume than the DFSMSrmm control data set. If the selected volume is system-managed, use the STORCLAS parameter as shown in Figure 1, and select a storage class with the GUARANTEED SPACE attribute. By using the GUARANTEED SPACE attribute, you ensure that the journal is allocated to a specific volume. This volume is different than the one on which the control data set resides. Remove the STORCLAS parameter if the volume is not system-managed.

Place the DFSMSrmm journal on the highest performing DASD in your installation. DFSMSrmm can benefit from features like caching and DASD fastwrite and support for concurrent copy. Consider using the storage class attribute AVAILABILITY=CONTINUOUS for the journal.

Systems sharing a control data set must also share the same journal.