Migration is the conversion of programs and data to work with a new code level of
IBM MQ . Some types of migration are required, and some
are optional. Queue manager migration is never required after applying a maintenance level update,
that does not change the command level. Some types of migration are automatic, and some are manual.
Queue manager migration is typically automatic and required after releases and manual and optional
after a maintenance level upgrade that introduces a new function. Application migration is typically
manual and optional.
Before you begin
Before upgrading your IBM MQ installation or
migrating your queue managers, you must read Changes that affect migration to identify what migration
tasks you must plan for.
About this task
Whenever you upgrade IBM MQ to a new release that
changes its command level, migration is performed by the queue manager. Whenever you upgrade
IBM MQ to a new maintenance or fix level, which
introduces a new function using a new command level, we can migrate the queue manager to use the
new command level and thereby the new function.
If you start a queue manager running on a later release level, then migration of the queue
manager to that release level is required. The migration tasks you must perform to migrate from one
release to another are documented in Migrating a queue manager on Windows; see also Changes that affect migration.
On IBM MQ for Multiplatforms, we cannot easily revert to a previous level of IBM MQ after installation. If you install a copy of IBM MQ obtained from Passport Advantage® or from physical media, the installer uninstalls
IBM MQ, if it is present. It then installs the new level
of IBM MQ. To revert to the previous level of IBM MQ, you must keep the earlier installation image and any
fixes you applied. Then you must uninstall the new level, reinstall the previous release level, and
reapply the required fixes. If we have started any queue managers at the later level, they will not
work with the restored level of IBM MQ 1 . To restore IBM MQ to its previous level, after starting any queue managers,
you must first back up the queue managers. We can then restore the backup queue managers after
restoring the previous level of IBM MQ.
Backwards migration is not supported for a Continuous Delivery (CD) release on z/OS.
1 Unless you installed a later maintenance level upgrade, not a new release or version: then you
could revert to an earlier maintenance level by reinstalling the earlier maintenance level upgrade.
On IBM MQ for z/OS®,
while OPMODE is set to COMPAT, it is possible to backwards migrate from a
Long Term Support (LTS) release. For more information, see Backward migration to earlier supported releases of IBM MQ for z/OS.
Backwards migration is not supported for a Continuous Delivery (CD) release on z/OS.