Conversion Procedures › Migrating to Dynamic Cache Management › Quick Migration › Perform a Quick Migration

Perform a Quick Migration

Quick Migration assumes that relatively few CA Vtape Subsystems are involved and that sufficient additional DASD space is available to create a dynamic cache DASD pool the same size as the static cache DASD pool. This allows all of the subsystems to be converted at the same time.

To perform a Quick Migration

1. If you have more than one CA Vtape Complex, pick one complex to start with.
2. Change the cache management mode to dynamic by setting CacheManagement=DYNAMIC in the Startup Options Section of the CA Vtape Parmlib. If multiple subsystems are active in the chosen complex, check each one to ensure that they are all using the updated Startup Options Section. If they are not, update all of the Startup Options Sections in use.
3. Stop and start all of the updated subsystems. All new scratch mounts will now be written to dynamic LDSs.

   Note: Until Step 6 is completed, mounts of existing Virtual Volumes will be performed in the mode that the volume was originally created in. Virtual Volumes created before changing to dynamic will be read and recalled in the static cache.

4. You can use the SVTn Display Parmlib,Short console command to check if each restarted subsystem is running in dynamic mode.
5. Execute the GRRJCL batch utility to ensure that all Virtual Volumes that need to be Externalized are queued for Externalization. Then use SVTn Display Group and SVTn SET BACKstore console commands to ensure that any queued Virtual Volumes are Externalized.

   Note: If any Virtual Volumes created in static mode cannot be Externalized, take the necessary actions to copy any needed application data sets to DASD or physical tape and scratch the Virtual Volumes.

6. After all static mode Virtual Volumes are Externalized, you can convert them to dynamic mode by executing the SVTSUTIL batch utility with the following command:

   RESET_CACHETYPE=DYNAMIC
   

   Each static Virtual Volume Entry in the Global VCAT will be converted to dynamic. It takes approximately 18 minutes to convert 20,000 active Virtual Volumes when the subsystems are under a light workload. Executing the utility when the subsystems are under a heavy workload will cause delays due to competition for the Global VCAT and BSDS.

   The program will produce an error report for any unconverted Virtual Volumes. These are typically Virtual Volumes that were not Externalized or were active or mounted when the utility was executed.

   Note: You can repeat Steps 5 and 6 as often as necessary in order to convert all of the existing static Virtual Volumes.

7. Execute jobs to test the allocation of new and old Virtual Volumes by the subsystems running in dynamic mode. All Virtual Volumes should be written into dynamic LDSs with a data set name pattern of prefix.VVE.Vvolser.MM.CACHE.
8. After you are satisfied that dynamic mode is working properly and you no longer intend to return to static mode, you can reclaim the space assigned to static mode LDSs by executing the SVTSUTIL batch utility with the following command:

   LDS_DELETE
   

   This will delete all static cache LDSs from both DASD and the CA Vtape Global VCAT.

   Note: For more information about the command and its parameters, see the chapter “SVTSUTIL Batch Commands.”

9. Repeat all of the preceding steps for the next complex to be converted.

   All your complexes are converted.