Upgrade and migration of IBM MQ on z/OS

You can install new releases of IBM® MQ to upgrade IBM MQ to a new release, version or modification (VRM) level. Running a queue manager at a higher level to the one it previously ran on requires migration.

From IBM MQ for z/OS® 9.0.0, the way you upgrade the systems in your enterprise has changed. For more information, see IBM MQ Release Types and versioning.

When you install a new level of IBM MQ on z/OS using SMP/E, it creates a set of IBM MQ libraries. The libraries for different levels of IBM MQ can coexist on the same instance of z/OS, allowing you to run different queue managers against different levels of IBM MQ on the same z/OS LPAR.

If you start a queue manager running on a later release level, then migration of the queue manager to that release level is required, even if the difference is only in the modification level, some migration might be required. The migration tasks that you must perform to migrate from one version to another are documented in Planning to migrate IBM MQ for z/OS to IBM MQ for z/OS 9.3; see also Changes that affect migration.

Backwards migration

Migration from IBM MQ for z/OS 9.1.0 or 9.2.0 to IBM MQ for z/OS 9.3.0 Long Term Support (LTS) or IBM MQ for z/OS 9.3.0 Continuous Delivery (CD) releases are reversible; this reversal process is known as backwards migration.

Backwards migration is only supported if a queue manager was previously migrated.

Notes:

1. There is no longer a need to install migration and coexistence PTFs to enable backwards migration. The backwards migration process for version 9.3.0 is described in Reverting a queue manager to a previous version on z/OS.
2. Migration from a CD release, such as IBM MQ for z/OS 9.2.5 to IBM MQ for z/OS 9.3.0 LTS or CD is not reversible, neither is migration to a CD release, unless that CD release is IBM MQ for z/OS 9.3.0 CD.
3. Migration from releases earlier than IBM MQ for z/OS 9.1.0 is not reversible; see Migrating from earlier unsupported releases of IBM MQ for z/OS.