Migrating your Db2 subsystem to Db2 13

The migration process for Db2 13 has a single phase. However, most new capabilities and enhancements in Db2 13 remain unavailable until you issue an ACTIVATE command to activate function level 500 or higher.

Before you begin

Before you begin migration to Db2 13, read all information in Preparing your system to install or migrate to Db2 13.

Start of change Ensure that your Db2 12 subsystem is at the proper service level and function level. For more information, see Required maintenance for Db2 13 installation or migration and Verify Db2 13 premigration activities and activate function level 510 in Db2 12. End of change

Attention: If you do not follow the documented procedures, unpredictable results might occur after migration to Db2 13.

Important: Before you can migrate a Db2 12 environment to Db2 13, you must complete premigration activities and activate function level 510 in Db2 12. For more information, see Verify Db2 13 premigration activities and activate function level 510 in Db2 12.

Important: Apply the for fallback SPE (APAR PH37108) and stop and restart Db2 12 for every subsystem or data sharing member that you plan to migrate to Db2 13. For data sharing, every member must be started in Db2 12 after the fallback SPE is applied. Inactive members that never started with the fallback SPE applied in Db2 12 cannot start in Db2 13 or Db2 12 after migration to Db2 13 and activation of function level 500 on any other member. See Required maintenance for Db2 13 installation or migration.

Tip: After you apply the PTF for APAR PH50072 in Db2 12, you can get a migration readiness report in the DSN7100I message by issuing DISPLAY GROUP command with the DETAIL keyword. The report includes a reason if your environment is not ready for migration to Db2 13. See Check readiness for migration to Db2 13.

About this task

When you start Db2, the code level of the starting Db2 is compared to the code level that is required by the current Db2 catalog. If the starting Db2 has a code-level mismatch with the catalog, Db2 does not start and a message is issued.

Refer to the Db2 Program Directory for keyword specifications that are used for Preventive Service Planning (PSP) and for information about the service levels of any coupling facilities. You can use the z/OS® DISPLAY CF command to display the service level of coupling facilities. Check Information/Access or the ServiceLink facility of IBMLink for PSP information before you migrate. Or, to help you identify required service, you can instead use enhanced HOLDDATA and fix categories (FIXCATs), which provide a simplified, automated method of identifying and applying missing PTFs that are required for installation or migration. Also, check monthly for current information about Db2.

Restriction: After migration to Db2 13, the administrative task scheduler is disabled until you run job DSNTIJRT.

Procedure

To migrate a Db2 for z/OS subsystem to Db2 13:

Estimate storage needs for your Db2 13 environment. For more information, see Storage requirements for Db2 for z/OS.
Determine the new capabilities that you want use in Db2 13, and make plans for other changes in the new release. For more information, see:
- What's new in Db2 13
- Changes to plan for in Db2 13
If you are using distributed data, install TCP⁄IP, VTAM, or both. For more information, see Connecting distributed database systems .
If you plan to use data sharing, set up a Parallel Sysplex®. For more information, see Parallel Sysplex requirements for Db2 data sharing.
Use SMP/E to load the Db2 13 libraries. For more information, see Making the Db2 product code available.

Remember: If you copy Db2 library data sets from one system another, such as for installing a related test or production subsystem, ensure that you copy all of the Db2 library data sets to the same location. For example, if you copy the SDNSLOAD data set from one system to another but omit the DBRMLIB data set, the resulting mismatch can cause job DSNTIJRT to fail with SQLCODE -812.

If you plan to use the callable SQL interface of Db2, see Configuring Db2 ODBC and running sample applications for the additional installation jobs that you need to run. If you plan to use Db2 for z/OS Java™ Edition, you must run more installation jobs. For more information, see Installing the IBM® Data Server Driver for JDBC and SQLJ.
Install needed service on Db2 12. For information about the required service to apply, see the Program Directory.

Important: Apply the for fallback SPE (APAR PH37108) and stop and restart Db2 12 for every subsystem or data sharing member that you plan to migrate to Db2 13. For data sharing, every member must be started in Db2 12 after the fallback SPE is applied. Inactive members that never started with the fallback SPE applied in Db2 12 cannot start in Db2 13 or Db2 12 after migration to Db2 13 and activation of function level 500 on any other member. See Required maintenance for Db2 13 installation or migration.
Check for release incompatibilities, and make the necessary changes in your applications. For more information, see Make adjustments for incompatible changes in Db2 13.
Generate tailored JCL jobs for migrating to Db2 13. You can use the DSNTIJBC batch job or the Db2 installation CLIST.
Tip: You can avoid working through the Db2 installation CLIST panels in interactive mode by running a batch job with valid input files to generate the required JCL jobs and input files with a background process. See Generating tailored Db2 migration or function level activation jobs in the background.
To generate the required JCL jobs and input files with a background process, complete the following steps:
1. Customize the DSNTIDOM parameter override file by following the instructions in the file.
2. Customize the DSNTIJBC job. For example, if prefix.SDSNSAMP(DSNTIDOM) is the customized parameter override file, you can specify the following values in the IPSTART command in DSNTIJBC.
```
  ISPSTART CMD(%DSNTINSB + 
    OVERPARM(prefix.SDSNSAMP(DSNTIDOM)) + 
    ) BREDIMAX(1)
```
3. Submit the customized DSNTIJBC job.
To generate the required JCL jobs and input files with the Db2 installation CLIST in interactive mode, complete the following steps. For more information, see Generating tailored installation, migration, or function level activation jobs by running the Db2 installation CLIST in interactive mode.
Complete the following migration tasks:
When you are ready to use new capabilities in Db2 13, activate new function as described in Activating Db2 13 function level 500 or higher.
Install, configure, and verify Db2-supplied routines that depend on Db2 13 function levels, as described in Installing and configuring Db2-supplied routines that use new function: DSNTIJRT.
Verify the successful migration to Db2 13, as described in Verifying successful migration to Db2 13.
Enable more capabilities in your Db2 environment. For more information, see Configuring additional capabilities for Db2 for z/OS.

What to do next

You might want to activate new capabilities that are introduced by higher Db2 13 function levels. For more information about continuous delivery and function levels in Db2 13, see the following topics:

Important: Do not issue the ACTIVATE command or run job DSNTIJAF for activation of Db2 13 until you are certain that the subsystem or data sharing group can proceed on Db2 13, without the possibility of falling back to or coexistence with Db2 12. In data sharing, the ACTIVATE command has group scope. Fallback and coexistence become impossible with the successful activation of function level 500 or higher.