Migration step 17: Refresh the z/OS definition of Db2

As part of the migration to Db2 12, you must refresh how Db2 is defined to z/OS.

Before you begin

Complete the following tasks:

Ensure that the early code pre-conditioning PTFs are installed on your system before you migrate. For details, see Required maintenance for Db2 12 installation or migration.
Determine the version of the ERLY code to include in the system link list, as described in Choosing link list options. In most cases, use the ERLY code that is distributed with the Db2 release you are migrating to. The link list can contain only one level of the early code, and it must support all Db2 subsystems and different Db2 releases that share it.
Update the definition for Db2 12 to IRLM and MVS, as described in Migration step 13: Define Db2 12 to IRLM and MVS: DSNTIJMV.

This migration task is necessary to apply changes for Db2 12 migration in the following z/OS structures:

The link list look-aside address space (LLA), which contains the Db2 12 early (ERLY) code from the SDSNLINK load module library.
Member IEAAPFxx, for new APF libraries.
Member LNKLSTxx, for new load module libraries.
JCL startup procedures for the Db2 12 address spaces, including WLM environments used by stored procedures and user-defined functions.
JCL procedures for preparing Db2 12 application programs.

Refresh how Db2 is defined to z/OS by using one of the following approaches:

Do an initial program load (IPL) of z/OS. You must choose this approach if you issued z/OS SETPROG LINKLST commands to refresh the system link list in member LNKLSTxx.
After the IPL of z/OS completes, message DSN3100I is displayed on the z/OS console, stating that Db2 is ready for the START command.
If you changed to a new version of the ERLY code, and you did not refresh the system link list in member LNKLSTxx, run the -REFRESH DB2,EARLY command from a z/OS console that has START command capability. When -REFRESH DB2,EARLY is run, previous copies of the ERLY modules are deleted from the system the next time that Db2 is started. -REFRESH DB2,EARLY is valid only when Db2 is not started.