Reorganizing the control data set

Use EDGBKUP to reorganize the control data set. The DFSMSrmm subsystem must be stopped or quiesced when you reorganize the active control data set. DFSMSrmm reorganizes the control data set by first backing up the control data set and optionally the journal. Then DFSMSrmm restores the control data set from the backup control data set. For more information, see the topic about reclaiming CA space in z/OS DFSMS Using Data Sets.

Do not use the BACKUP(DSS) parameter to reorganize the control data set. If you use BACKUP(DSS) to regularly back up for recovery purposes, use the EDGBKUP utility with the BACKUP(REORG) parameter with care. Although DFSMSrmm can determine which utility to use for recovery from any backup taken using an DFSMSrmm utility, any backup taken during BACKUP(REORG) might impact the cycles that have been maintained of regular backup copies.

Example: Reorganize the control data set without backing up the journal.

//REORG     EXEC PGM=EDGBKUP,PARM='BACKUP(REORG)'
//SYSPRINT DD   SYSOUT=*
//BACKUP   DD   DISP=(,CATLG),DSN=RMM.BACKUP.CDS(+1),UNIT=SYSALLDA,
//         SPACE=(CYL,(ppp,sss),RLSE),RECFM=VB,LRECL=9216,
//         BLKSIZE=0
//MASTER   DD   DISP=OLD,DSN=RMM.CDS

Example: Reorganize the control data set and back up the journal. DFSMSrmm backs up the journal before attempting to restore the control data set because the JRNLBKUP DD and the JOURNAL DD statement are specified in this example.

//REORG    EXEC PGM=EDGBKUP,PARM='BACKUP(REORG)'
//SYSPRINT DD   SYSOUT=*
//BACKUP   DD   DISP=(,CATLG),DSN=RMM.BACKUP.CDS(+1),UNIT=SYSALLDA,
//         SPACE=(CYL,(ppp,sss),RLSE),RECFM=VB,LRECL=9216
//         BLKSIZE=0
//MASTER   DD   DISP=OLD,DSN=RMM.CDS
//JRNLBKUP DD   DISP=(,CATLG),DSN=RMM.BACKUP.JOURNAL(+1),UNIT=SYSALLDA,
//         SPACE=(CYL,(ppp,sss),RLSE),RECFM=VB,LRECL=9248,
//         BLKSIZE=0,BUFNO=30
//JOURNAL  DD   DISP=OLD,DSN=RMM.JOURNAL,BUFNO=30

These examples show how you can reorganize your current, or in use, control data set. This approach requires that the DFSMSrmm started task is stopped and a backup and restore operation is to be processed. Another approach to reorganizing the control data set is to allocate a new control data set and ensure that the control data set contents are reorganized as part of the copy to the new data set. See Steps for moving the control data set and journal using the DFSMSrmm EDGHSKP utility with the PARM='BACKUP' parameter for a process you can follow that also reorganizes the control data set contents. Be sure to remember that only a control data set backup using EDGHSKP with the BACKUP or BACKUP(AMS) parameter, or EDGBKUP with the BACKUP, BACKUP(NREORG), or BACKUP(REORG) parameter, reorganizes the control data set contents.

You can significantly reduce the need to reorganize the control data set by enabling the CA reclaim function for it. For more information, see the topic about reclaiming CA space in z/OS DFSMS Using Data Sets.