Examples › Volume Defragmentation Examples › Solution—Defragmentation with ARCHIVE and RECOVER

Solution—Defragmentation with ARCHIVE and RECOVER

Although the previous options are highly recommended as first alternatives (and you can be able to think of several others), the point can still be reached when defragging the volume must be done. The following comments outline a method to do this with the ARCHIVE and RECOVER commands, as well as providing some added benefits and tips to keep in mind.

To CA Disk, a volume defrag means the following:

1. Consolidate used tracks to obtain large contiguous free space extents.
2. Combine multiple extent data sets into a single extent. Compress PDS data sets.
3. Relocate and reorganize ISAM data sets.
4. Reorganize VSAM clusters.
5. Compress the VTOC.

A recommended approach to doing this with CA Disk is as follows:

1. If using an FDS, allocate and format a new mini FDS.
2. The advantage of using a separate files data set for this special function is that it keeps these reorganization index entries separate from the Archive/Backup entries, and reduces the time needed to process the files data set, since it contains fewer entries.
3. Establish a JCL procedure that uses it in a DSCL run that archives and scratches all data sets on the pack. Follow this with a RECOVER command to restore all of the data sets on the volume.

The following JCL can be used as a guideline for defragging a disk volume.

• First, create the FDS to be used.

  //jobname JOB (acct,info),etc.
  //INIT     EXEC PGM=ADSMI002,PARM=ADSDM100
  //STEPLIB   DD  DISP=SHR,DSN=CA.DISK.CCUWLOAD
  //ABNLDUMP  DD  DUMMY
  //CMDPRINT  DD  SYSOUT=A
  //FILES     DD  DSN=CAI.DISK.DEFRAG.volser.FILES
  //         DISP=(,CATLG,DELETE),UNIT=SYSDA,
  //         DCB=(DSORG=DA),SPACE=(CYL,2,,CONTIG)
  //MSGPRINT  DD  SYSOUT=A
  //PARMLIB   DD  DISP=SHR,DSN=CAI.DISK.CCUWPARM
  //SYSPRINT  DD  SYSOUT=A
  //SYSUDUMP  DD  SYSOUT=A
  

• Second, archive all non-VSAM data sets and VSAM clusters, from the desired volume.

  //DEFRAGV  EXEC DMS
  //SYSIN     DD  *
  //FILES     DD  DISP=SHR,DSN=CAI.DISK.DEFRAG.volser.FILES
  SCAN REALVOLS
  SELECT VOL=volser
  ARCHIVE
  

• Third, recover all the data sets to the volume only if they were scratched successfully at archive time.

  //RECOVER  EXEC FMS
  //FILES     DD  DISP=SHR,DSN=CAI.DISK.DEFRAG.volser.FILES
  //SYSPARMS  DD  *
  PREALLOCN              no need to restore if not scratched after archive
  VSPREDEFN              no need to restore if not scratched after archive
  //SYSIN     DD  *
  SCAN DSNINDEX
  SELECT DSN=dsnames
  RECOVER TOVOL=volser