Planning VSAM storage requirements

The MVS™ programmer uses the IKYCVSAM sample JCL to create two VSAM data sets (clusters):
  • A data set for the request database (object store)
  • A data set for the issued certificate list (ICL).
The MVS programmer also uses the same sample JCL to create five alternate index data sets (paths):
  1. Transaction ID alternate index into the object store
  2. Status alternate index into the object store
  3. Requestor alternate index into the object store
  4. Status alternate index into the ICL
  5. Requestor alternate index into the ICL.

The IKYCVSAM sample JCL contains default values for the primary and secondary extent allocations for these data sets. The default allocation for base clusters is CYL(3,1). For alternate indexes, it is TRK(5,1). You need to update these values based on your anticipated future needs. Use the guidelines in Determining storage needs for the ICL and Determining storage needs for the object store to update the space allocation parameters for the DEFINE CLUSTER and DEFINE ALTERNATEINDEX statements. (For more information about IDCAMS, see z/OS DFSMS Access Method Services Commands.)

Parent topic: Creating the object store and ICL using VSAM data sets