Maintaining DFSMShsm control data sets

These control data sets and the DFSMShsm journal are what make it possible for you to rely on DFSMShsm’s record keeping to perform all of its activities. Therefore, you need backup copies of them to allow you to recover data should the active control data sets become lost or damaged.

DFSMShsm provides for automatic backup of the control data sets and the journal each time that automatic backup is performed for the system. In addition, you can back up the control data sets by command.

The primary host is the only host that normally performs an automatic CDS backup. If the primary host fails, a secondary host can take over the functions of the failed primary host.

To enable you to recover a lost or damaged control data set, DFSMShsm maintains a journal of each transaction that occurs to the control data sets. Should a control data set be damaged or lost, you can recover a backup version of the control data set and apply the transactions recorded in the journal to bring the control data set back to current status.

In addition to showing how to manage the control data sets automatically, the method of issuing commands necessary to determine the condition of the data sets and to repair them if necessary is discussed.