Preventing Inadvertent Migration of DB2 Data

Database data sets may stay open for a number of days. To prevent them from being inadvertently migrated during the DFSMShsm automatic space management cycle, DFSMS updates the last-referenced date when data sets are closed or when databases are shut down. However, this update and close process is bypassed for DB2® data sets if the system chooses to use the DB2 fast shutdown option. As a result, DB2 data sets can be unintentionally migrated, and if so, it can take a long time for the unintended migrations to be recalled during the database start-ups.

You can prevent inadvertent migration of DB2 data in one of the following ways:

Assign a management class with Command or Auto Migrate = None.
Assign a management class with Command or Auto Migrate = Command. This specification prevents DFSMShsm from automatically migrating DB2 data during the primary space management cycle, but it allows you to migrate test databases on command.
Assign a management class with Primary Days non Usage > nn days, where nn is greater than the number of days when these data sets stay open.
Modify the relevant DB2 database settings. Contact your IBM® DB2 Service Support Representative for further information.