Recommendation: With closed-cycle GDGs, you might use more volumes than you actually require. Consider moving to a scratch-pool-based system to use your volumes more efficiently.

1. Update the JCL that your applications use for creating the generations of their data sets on tape.
   • Modify the JCL to remove any special utilities that might be used to catalog the closed cycles.
   • Remove any references to the oldest generation of the GDG.
   • Ensure that the DD statement for the new generation does not indicate any volumes. The system will request a non-specific tape mount.
2. Update the vital record specifications shown in Figure 1. You can now use retention while cataloged and can optionally use the maximum number of generations that you want to be retained.

   Modify the vital record specifications as shown in Figure 1.

   Figure 1. Managing volumes using scratch pools

   RMM ADDVRS DSNAME('SAMPLE.GDG') GDG CYCLES COUNT(3) LOCATION(ATL1) -
       STORENUMBER(1) NEXTVRS(N1) WHILECATALOG
   RMM ADDVRS NAME(N1) STORENUMBER(1) LOCATION(REMOTE)

During the first inventory management run after these changes have been made, DFSMSrmm considers all the unwanted older generation volumes for release and expiration processing.