If you are upgrading from an existing version 1.2 system, there are a number of actions to be performed, which are described in this section.
The version 1.2 APAR PM16132 must be applied before you upgrade to version 2.1. The CICS® VT control tables and mapping data must also have been migrated according to the instructions with PM16132. You can confirm this by running a DB2® query against the catalog table SYSIBM.SYSCOLUMNS for the CICS VT control table cvt.DSN_MAP and verifying that the COLTYPE=VARCHAR and LENGTH=128 for the column VIDSPCRE.
You must run the installation customization using the version 2.1 data sets. This ensures that version 2.1 objects are tailored for your environment