[V9.1.0 Aug 2018][z/OS]

OPMODE on z/OS

In earlier versions of IBM® MQ for z/OS® the availability of new functions and backward migration was controlled by the OPMODE parameter in the CSQ6SYSP macro. In IBM MQ 9.1.0 this no longer applies, and the OPMODE parameter is ignored.

None of the new function provided in IBM MQ 9.1.0 has any impact on backwards migration.

A queue manager started at IBM MQ 9.1.0 can be backwards migrated to IBM MQ 8.0.0, provided that:
  1. It has previously been started at IBM MQ 8.0.0
  2. The IBM MQ 9.1.0 backwards migration PTFs have been applied to the IBM MQ 8.0.0 installation before starting at IBM MQ 9.1.0.
A queue manager started at IBM MQ 9.1.0 can be backwards migrated to IBM MQ 9.0.0, provided that:
  1. It has previously been started at IBM MQ 9.0.0
  2. The IBM MQ 9.1.0 backwards migration PTFs have been applied to the IBM MQ 9.0.0 installation install before starting at IBM MQ 9.1.0.

Following the instructions described in Preparing to migrate a single IBM MQ for z/OS queue manager, will ensure that backwards migration is possible.

A queue manager started at an IBM MQ 9.0.n CD release can be forward migrated to IBM MQ 9.1.0. However it cannot be subsequently backwards migrated to IBM MQ 9.0.n CD release.

A queue manager started at IBM MQ 9.1.0 cannot be backwards migrated to a version earlier than IBM MQ for z/OS 8.0.0. Queue managers running at IBM WebSphere® MQ 7.0.0, 7.0.1, or 7.1.0 must first be migrated to IBM MQ 8.0.0 or 9.0.0, before being migrated to IBM MQ 9.1.0.

Important: Before migrating to IBM MQ 9.1.0, you should first start your IBM MQ 8.0.0 or 9.0.0 queue manager in NEWFUNC mode. That is, for IBM MQ 8.0.0, start your queue manager with OPMODE=(NEWFUNC,800), and for IBM MQ 9.0.0, start your queue manager with OPMODE=(NEWFUNC,900) or OPMODE=(NEWFUNC,800).

If you, instead, leave your IBM MQ 8.0.0 or 9.0.0 queue manager in COMPAT mode, and then migrate to IBM MQ 9.1.0, you will be able to enable function that is not compatible with COMPAT mode in IBM MQ 8.0.0 or 9.0.0, such as buffer pools with a LOCATION of ABOVE. This will cause problems if you subsequently migrate back to IBM MQ 8.0.0 or 9.0.0, because you will need to change to NEWFUNC mode before you start your queue manager, otherwise the queue manager might not start.

The DISPLAY SYSTEM command no longer returns information on OPMODE. The following messages have been added to queue manager start up to indicate whether backwards migration is available or not:
  • CSQY040I: Backwards migration is not supported
    This message will be output when backwards migration is not supported. This is the case when the queue manager:
    1. Has been created at the current release
    2. Has been migrated from an earlier CD release
    3. Has been migrated from a release earlier than IBM MQ 8.0.0
  • CSQY039I: Backwards migration is supported to version V.R.M

    This will be output when backwards migration is supported. V.R.M will be one of 8.0.0 or 9.0.0, which is the version of the product at which the queue manager had previously been started.

    Note that this statement assumes that the IBM MQ 9.1.0 backwards migration PTFs have been installed at either IBM MQ 8.0.0 or 9.0.0, before starting at IBM MQ 9.1.0.