Conversion Procedures › Migrating to Dynamic Cache Management › Return to Static Cache Management Mode

Return to Static Cache Management Mode

Use the following procedure to revert back to static mode.

To revert back to static mode

1. If you have deleted the static cache LDSs, the recovery jobs, created when SVTSUTIL was executed with the LDS_DELETE command, can be executed to re-create them. These jobs create, initialize, and add back the static cache LDSs.

   Note: If after converting to dynamic cache you also converted to 2000 MB Virtual Volumes, you cannot convert back to 400 or 800 MB Virtual Volumes. This will cause any 2000 MB Virtual Volumes to be lost. Execute the Define option of the CA Vtape ISPF Customization Process to generate a new SUTPARMS member with a Virtual Volume Size of 2000 MB and to generate the DEFLDSxx and LDSADDxx jobs to define, initialize, and add 200 MB cache LDSs to the Global VCAT.

2. Update the VTPARMS parmlib member to set CacheManagement=STATIC in the Startup Options Section and CacheFreeSpaceThreshold=0 in the Dynamic Options Section.
3. Refresh your parmlib options using the SVTS REFRESH=OPTION command. This enables the parmlib option CacheFreeSpaceThreshold=0 and allows the SVTS subsystem to begin releasing all the dynamic cache space associated with Virtual Volumes that have been Externalized.
4. To convert existing Virtual Volumes from one mode to the other, you must externalize them to physical tape.

   First, run GRRJCL to ensure that all Unexternalized Virtual Volumes are queued for Externalization. Then use the SVTn Display Group and SVTn SET BACKstore commands to ensure that dynamic Virtual Volumes are queued and being Externalized.

5. Restart the SVTS subsystems.
6. Run SVTSUTIL with the following command:

   RESET_CACHETYPE=STATIC
   

   This will convert the existing dynamic Virtual Volumes to static mode. You may need to do this step more than once if the report shows errors.