Restoring the control data set with forward recovery

Figure 1 shows the JCL for restoring the DFSMSrmm control data set and for forward recovering the DFSMSrmm control data set. You can restore the control data set directly from tape by using the EDGBKUP utility when DFSMSrmm is stopped or quiesced. You do not need to use the EDGRESET utility or the MODIFY command to reset DFSMSrmm. EDGBKUP uses either the DFSMSdss RESTORE command or the AMS REPRO utility to restore the control data set based on the contents of the control data set backup.

Figure 1. Restoring the control data set with forward recovery

//EDGBKUP  EXEC PGM=EDGBKUP,PARM='RESTORE'
//SYSPRINT DD   SYSOUT=*
//MASTER   DD   DISP=SHR,DSN=RMM.CDS
//*
//BACKUP   DD   DISP=SHR,DSN=BACKUP.CDS(0)
//*
//JOURNAL  DD   DISP=SHR,DSN=BACKUP.JRNL(0)
//         DD   DISP=SHR,DSN=RMM.JOURNAL

You must specify the MASTER DD statement to restore from an AMS REPRO backup and to forward recover an existing control data set.

The MASTER DD is optional when you restore the control data set from a DFSMSdss backup. In this way, you do not have to pre-allocate the control data set, and you can optionally restore to a control data set by using a different data set name. After the DFSMSdss restore is completed, DFSMSrmm dynamically allocates the MASTER file to the restored data set prior to starting forward recovery. If the MASTER DD statement is specified, the data set name must match the data set name that DFSMSdss restores.

You can restore the DFSMSrmm control data set and forward recover the restored control data set with journal records. Use the JOURNAL DD statement to concatenate multiple journal data sets. If you forward recover using multiple journal data sets, concatenate the journal data sets in the order in which changes were originally made. The first journal data set in the concatenation must match the control data set to be forward recovered. For control data set backups that are taken with AMS REPRO, DFSMSrmm considers the matching journal to be the one that contains records that are created after the journal was cleared. For control data set backups that are taken with DFSMSdss, DFSMSrmm considers the matching journal to be the journal in use at the time the backup is taken.

Example: The example shows how to restore from the second generation backup. Concatenate journal data sets for back up using AMS REPRO.

//BACKUP   DD       DISP=SHR,DSN=BACKUP.CDS(-2)
//JOURNAL  DD       DISP=SHR,DSN=BACKUP.JOURNAL(-1)
//         DD       DISP=SHR,DSN=BACKUP.JOURNAL(0)
//         DD       DISP=SHR,DSN=RMM.JOURNAL

Example: The example shows how to restore from the second generation backup. Concatenate journal data sets for back up using DFSMSdss.

//BACKUP   DD       DISP=SHR,DSN=BACKUP.CDS(-2)
//JOURNAL  DD       DISP=SHR,DSN=BACKUP.JOURNAL(-2)
//         DD       DISP=SHR,DSN=BACKUP.JOURNAL(-1)
//         DD       DISP=SHR,DSN=BACKUP.JOURNAL(0)
//         DD       DISP=SHR,DSN=RMM.JOURNAL

When backup is taken using AMS REPRO and you restore the control data set from the latest control data set backup, use the active journal to forward recover to the latest point in time.

When backup is taken using BACKUP(DSS) and you restore from the latest control data set backup, both the latest journal backup and the active journal must be used for forward recovery. For information about restoring the control data set at a recovery site, see Restoring the control data set at a recovery site.