Migrating the log of your queue manager from circular to linear

Follow this sequence of steps to migrate your queue manager log from being circular to linear.

Before you begin

Before you migrate, take a backup of your queue manager.

Decide whether you want to migrate your log in place, or migrate the log to a new location by specifying the -ld option on the migmqlog command. If you are moving your queue manager from an old disk to a new Advanced Format disk, it might be convenient to use the -ld option.

Make sure that we have enough space to migrate your log, as the log might grow during migration.

Note the following:

• You do not need to migrate the log of your queue manager in order to use IBM MQ Version 9.0.4.
• migmqlog might take some minutes to complete if your log is very large. However, the command outputs progress messages from time to time.
• If, for any reason (for instance due to a power outage) migmqlog stops before it has completed the process, rerun the same migmqlog command on the partially migrated logs to complete the migration.
• If you specified the -ld option, migmqlog updates the log path in the qm.ini file for you, so when you start your queue manager it will use the migrated log.
• Do not pass a relative path when using the -ld option; only use an absolute path.
• migmqlog does not update any queue or queue manager objects.

Attention: After we have migrated, a media image will not have been recorded when the queue manager starts. Plan how you intend to record media images, either automatically by setting the attributes:

• IMGSCHED
• IMGINTVL
• IMGLOGLN
• IMGRCOVO
• IMGRCOVQ

in ALTER QMGR, or manually by periodically running rcdmqimg.

Procedure

1. Login as a member of the mqm group.
2. If we have not already done so, take a backup of your queue manager.
3. Run the following command:

   migmqlog -m QMgrName -ll

   See migmqlog for more information.
4. Start the queue manager, and set the appropriate image recovery and queue attributes for your environment.
5. Consider when to record manual images for objects that are recoverable.