Example 3: Recovering the MCDS from tape when the latest MCDS backup version is unusable

This example shows how to set up your environment, how to recover the MCDS when the most recent backup version is unusable, and the processing that occurs when recovering the MCDS.

Set up your environment with the following SETSYS command: 
SETSYS CDSVERSIONBACKUP(DATAMOVER(DSS) -
     BACKUPCOPIES(6) -
     MCDSBACKUPDSN(BHSM.MCDS.BACKUP) -
     BCDSBACKUPDSN(BHSM.BCDS.BACKUP) -
     OCDSBACKUPDSN(BHSM.OCDS.BACKUP) -
     JRNLBACKUPDSN(BHSM.JRNL.BACKUP) -
     BACKUPDEVICECATEGORY(TAPE))

Assume DFSMShsm has successfully backed up the control data sets and the journal data set six times, and the latest final qualifier is D0000006. Therefore, backup data sets with final qualifiers of D0000001 through D0000006 exist on tape volumes.

If an error occurs so DFSMShsm cannot access the MCDS, you:

  1. Issue QUERY CDSVERSIONBACKUP and observe that the latest final qualifier is D0000006.
  2. Using DFSMSdss, restore the MCDS backup version of D0000006. Assume that, when you attempt this restore, the restore fails. You must now use MCDS backup version BHSM.MCDS.BACKUP.D0000005.
  3. Using DFSMSdss, restore the MCDS backup version of D0000005.
  4. Using IDCAMS, export the D0000005 backup version of the MCDS that was restored in step 3. The following example shows JCL that can be used to do the export: 
             //EXPORT JOB ,MSGLEVEL=(1,1),MSGCLASS=A,REGION=1024K
         //STEP1  EXEC PGM=IDCAMS
         //SYSPRINT DD SYSOUT=*
         //OUTDD1   DD DISP=(,CATLG,DELETE),BUFNO=26,BLKSIZE=28332,
         //            SPACE=(CYL,(200,20),RLSE),
         //            UNIT=3390,VOL=SER=333333,
         //            DSN=BHSM.MCDS.BACKUP.TEMP
         //SYSIN    DD *
            EXPORT BHSM.MCDS.BACKUP.D0000005 -
            OUTFILE(OUTDD1) -
            TEMPORARY
         /*
    Where:
    • BHSM.MCDS.BACKUP.TEMP is the data set name of the exported copy being created.
    • BHSM.MCDS.BACKUP.D0000005 is the data set name of the control data set being exported.
    • BLKSIZE=28332 is the capacity of half a track on a 3390 device.
  5. Stop DFSMShsm in all processing units.
  6. Create the backup journal file using the online journal and the latest backup copy of the journal. Use ARCBJRNL and PARM='BOTH', JRNLO DD for the online journal, and BKUPJRNL DD for the journal backup copy version D0000006 to create the backup journal file. See Implementing enhanced CDS recovery using JCL for an example of the JCL needed to create the backup journal file.
  7. Sort this newly created backup journal file. See Implementing enhanced CDS recovery using JCL for an example of the JCL needed to sort the backup journal file.
  8. Import and merge the exported MCDS from step 4 and the sorted backup journal file from step 7 using ARCIMPRT. Again, see Implementing enhanced CDS recovery using JCL for an example of the JCL needed to do the import and merge.
  9. Use the PATCH parameter of the FIXCDS command to update the MHCR to version 6, the latest control data set backup version.
  10. Issue the BACKVOL CDS command to obtain a new set of backup copies of the control data sets and journal data set. When DFSMShsm successfully backs up these data sets, the latest backup copies are those data sets whose final qualifier is D0000007.

DFSMShsm uncatalogs the D0000001 backup version. Only versions D0000002 through D0000007 remain cataloged.

Parent topic: Recovery examples using the enhanced CDS recovery function