Perform Step 13 once for each RMMplex or z/OS image, depending on how you created the control data set. Create one control data set and one journal for each RMMplex.

The journal contains a record of all changes made to the control data set since the last backup. Create the journal and use it to forward recover changes made since the last backup. Each time the control data set is backed up successfully using the EDGHSKP utility, the journal data set is cleared.

DFSMSrmm requires UPDATE access to the journal. The journal cannot be an extended sequential data set.

When not shared with a z/OS release below z/OS V1R12, the DFSMSrmm journal can be placed in an extended addressing space (EAS) on an extended address volume (EAV). See z/OS DFSMS Using the New Functions for more information on EAS and EAV.

You should plan to back up the journal and maintain multiple generations of it. See Performing inventory management for additional information.

You can create a large format journal data set by deleting and reallocating the journal data set by specifying DSNTYPE=LARGE in the JCL. A large format data set does not actually have to be more than 65 535 tracks.

If you want to implement a large format journal data set in an existing DFSMSrmm installation, see Maintaining the control data set for the procedures on reallocating or moving the journal. Also, look at the EDGJNLAL and EDGPBKP samples. They include the DSNTYPE=LARGE keyword.