Restarting Db2 after termination in a data sharing environment

After a failure or after a normal shutdown of Db2, you can restart Db2 with the -START DB2 command.

You can also choose to have Db2 automatically restart after a failure by using the automatic restart manager of z/OS®.

During restart, Db2 resolves inconsistent states. Restart is different in a data sharing environment in the following ways:

Database exception states exist on both the SCA and the log in a data sharing environment. The database exception states exist solely on the log in non-data-sharing environments.
Locks that are retained in the event of a failure must be processed.
If the SCA or the lock structure is lost and cannot be rebuilt on another coupling facility, all members of the group come down. If this unlikely event occurs, then Db2 must perform group restart. Group restart is distinguished from normal restart by the activity of rebuilding the information that was lost from the SCA or lock structure. Group restart does not necessarily mean that all members of the group start up again, but information from all non-starting members must be used to rebuild the lock structure or SCA.
You can set the DEL_CFSTRUCTS_ON_RESTART subsystem parameter to YES to automatically attempt to delete and rebuild the coupling facility structures whenever Db2 is restarted. For systems that are used for disaster recovery, set this parameter to YES to ensure that the coupling facility structures are up to date when the restart is complete. For production systems, set this parameter to NO.