CICS VSAM Transparency for z/OS, Version 1.2


Upgrading the batch subsystem

Actions are required to upgrade an existing CICS® VT version 1.2 system to version 2.1. Prior to performing the required actions, it is essential to understand the difference between version 1.2 and version 2.1 subsystems.

Prior to upgrading

Certain JCL changes have always been required to enable a batch job to access a VSAM data set migrated to DB2® with CICS VT. One of the required changes applies to the DD statements that define the migrated VSAM data sets; you must add a SUBSYS statement and appropriate CICS VT parameters. When the SUBSYS parameter is added, the CICS VT subsystem handles all VSAM calls to this DD.

The version 1.2 subsystem ignores other JCL parameters in the VSAM data set DD statement. The version 2.1 subsystem has a new migration status facility. This facility is sensitive to the existence of the DSN parameter. For your original version 1.2 migration, you may have added SUBSYS and without removing other DD statement parameters, including DSN=original.VSAM.dataset. If the version 2.1 subsystem detects a DSN parameter, the migration status facility is invoked. A new version 2.1 module VIDFMSP is loaded. If you are not using the version 2.1 library in your JOBLIB/STEPLIB, your application program abends and the message VIDSS204 referring to module VIDFMSP is issued.

You should review the JCL for all your files migrated with version 1.2 and remove all DSN= parameters prior to upgrading to version 2.1.

Prior to upgrading, you should let any existing batch jobs using CICS VT complete, and prevent any new CICS VT batch jobs from starting.

Upgrading subsystem initialization modules

The batch subsystem uses the libraries cvt.SVIDLPA and cvt.SVIDLINK. The same SVIDLPA and SVIDLINK module names are used for initializing version 1.2 and version 2.1 subsystems. These modules are upward and downward compatible. For each instance of a CICS VT subsystem the following method is recommended:

  • The version 1.2 SVIDLPA and SVIDLINK libraries or library names are reused for the version 2.1 libraries.
  • The version 1.2 batch subsystem name is used for the version 2.1 batch subsystem.

Use IEBCOPY to copy the version 2.1 SVIDLPA and SVIDLINK libraries over the version 1.2 libraries.

If you want to keep separate version 1.2 and 2.1 subsystems, you can define a new subsystem by following the instructions in Installing the batch subsystem.

Updating subsystem modules

SVIDLPA and SVIDLINK modules are only used during subsystem initialization. CICS VT subsystems defined in your system PARMLIB library are initialized at a system IPL. New CICS VT subsystems defined dynamically are initialized immediately. The CICS VT utility VIDUTILU dynamically updates an existing subsystem by reloading the LPA modules. This means that you can enable a version 2.1 subsystem and immediately exploit the batch migration status facility.

To update an existing version 1.2 subsystem to version 2.1, the first step is to back up your existing version 1.2 SVIDLPA and SVIDLINK libraries. Next, copy the entire version 2.1 SVIDLINK and SVIDLPA libraries to the existing version 1.2 libraries using IEBCOPY or an equivalent utility.

Activate the version 2.1 libraries with the following z/OS® commands:

F LLA,REFRESH
SETPROG LPA,ADD,MODNAME=VIDSSLPA,DSNAME=cvt.SVIDLPA 
SETPROG LPA,ADD,MODNAME=VIDSSLPB,DSNAME=cvt.SVIDLPA

The final step is to run the my.SVIDCNFG.custom member VIDUTILU. Note that the VIDUTILU parm statement assumes the default CICS VT subsystem name of VIDS. Change this if required.

These dynamic changes are hardened at the next system IPL.

If you have decided to configure a new subsystem for version 2.1, follow the instructions in Installing the batch subsystem. The VIDUTILU utility is not required for a new subsystem.





Last updated: November 9, 2012 20:42:51