Enabling multiple Db2 subsystems to share disk storage

If you use a non-data sharing environment, you can enable multiple Db2 subsystems to share disk storage. If you use a data sharing environment, the logs must be on shared disk storage.

Procedure

To share disk storage among Db2 subsystems and avoid problems with your active and archive log data sets:

  • Ensure that each subsystem has unique log data set names. This prevents situations like the following:

    Subsystem A on operating system 1 and subsystem B on operating system 2 share the same z/OS® catalog name, and their log data set names are the same. You start subsystem B while subsystem A is still running on operating system 1. This causes log data sets to be allocated for subsystem A, even though they already exist.

  • Use GRS, or an equivalent, and include your active and archive log data sets in the GRS inclusion list. This prevents situations like the following:

    Subsystem A on operating system 1 and subsystem B on operating system 2 share disk storage, and the active log is in a shared disk volume. Subsystem B fails. You attempt to start subsystem B, but you accidentally start subsystem A on operating system 2, even though it is still running on operating system 1. This causes log data sets to be allocated for subsystem A, even though they already exist.