General migration considerations

When you migrate to CICS® VR V6.1 from an earlier CICS VR version, you must take precautions to avoid losing data if any problems occur during migration.

Therefore, consider using the following steps before migration:
  • Create backups of all of your production VSAM spheres.
  • Create a backup copy of at least one CICS VR RCDS, if a previous version of CICS VR exists.
  • The CICS CSD definitions are supplied in DWWCSD for CICS VR V6.1; see Preparing for Automated Recovery for the sample JCL. Update the definitions, following these steps:
    1. Delete group DWWCICVR.
    2. Run the CICS VR V6.1 DWWCSD job to create a new DWWCICVR group that contains the updated definitions.
      Note: The transaction IDs DWWD, DWWE,and DWWX are changed to CVRD, CVRE, and CVRX respectively, to be used exclusively by CICS VR.

It is highly advisable to perform migration during a time when no VSAM spheres are being updated. Also, remember that different levels of CICS VR can run concurrently and independently of each other, if they are using different recovery control data sets (RCDSs). Therefore, you can install and test CICS VR V6.1 while you continue to use the previous CICS VR release until you verify that migration has completed successfully. You can activate only one CICS VR address space for each MVS image.

The steps required to migrate to CICS VR V6.1 differ depending on whether you are migrating from an earlier release, or from another forward recovery product. The next two topics list the steps required to migrate to CICS VR V6.1.

If you are using automated recovery, it is advisable to update your PLT to add program DWWSFCBF; see Automated Recovery and Reorganization for more information.