The CA Datacom/AD and CA Datacom/DB installation jobs use a default name for the creation and initialization of the Directory (CXX) file. If these jobs are run multiple times to create new Datacom environments, it is possible that the same name could be used for multiple CXX files. In addition to resolving duplicate CXX names created during installation, there may be other technical or business reasons to make changes to the CXX name in an established environment.
What is the process to change the CXX name in these situations?
The CXX name is one of the key identifiers (along with the MUF name) to identify the components of a Multi-User Facility (MUF) environment. This name is used extensively in an external security configuration, and as such, should be unique to ensure the proper level of security is implemented for each database environment using the MUF. In addition, the Datacom environment uses the CXX name as part of its integrity checking, by ensuring that control blocks in each physical database file (which hold Area and Index data) match the information in the CXX.
If the CXX name is not changed during successive executions of the installation jobs, it is possible that multiple MUFs and CXX files will use the same internal name. This could lead to confusion and error, and this procedure can be used to change the CXX name and properly adjust the control blocks to correct this situation.
Process Overview: Take a backup of the existing CXX data, re-initialize the CXX with the new name, restore the data previously backed up, then reconnect each of the physical datasets used by the database areas and indexes into the CXX.
- Take a backup of the existing CXX file. See See Step 1 - CXX Backup in attached file for sample JCL.
2. Run a full Directory (CXX) report. See Step 2 - CXX Report in attached file for sample JCL. This report will identify all databases defined to the Directory (CXX) in the MUF.
3. Shut down the MUF, using your existing JCL or console command procedures.
- Initialize the CXX file with a new name. See Step 3 - CXX Init in attached file for sample JCL. Ensure that the CXX has a unique name (up to 8 characters) in the enterprise, and that DATACOM=AD or DATACOM=DB is entered appropriately.
- Restore the data from the backup taken in Step 1. See Step 4- CXX Restore in attached file for sample JCL.
- Start the MUF, using your existing JCL or console command procedures.
- Link each of the databases to the CXX. See Step 5 - CXX Link in attached file for sample JCL. Repeat each SYSIN card and modify for each DBID found in the CXX report that you ran in Step 2.
- Take a final system state backup of the CXX after all changes are complete. Use the same JCL as in Step 1, and change the backup file name as needed for retention.
Note: All JCL samples listed are provided as a guide to assist you. Parameters in italics in a statement indicate a value that you must supply. Code all statements to your site and installation standards. Please ensure that DBUTLTY is communicating with the desired MUF by executing DBUTLTY with the same System Identifier module (DBSIDPR) that is being used by the MUF, and that the correct load libraries (CUSLIB and CAILIB) are specified.
Environment: z/OS, z/VSE
Additional Information: Refer to the following links for -- CA Datacom/DB Database and System Administration Guide and to Datacom/DB DBUTLTY Reference Guide for z/OS.