Starting a backup queue manager

We can substitute a backup queue manager for an unrecoverable queue manager.

About this task

If an unrecoverable queue manager has a dedicated backup queue manager, we can activate the backup queue manager in place of the unrecoverable queue manager.

When an unrecoverable queue manager is substituted with a backup queue manager, some of the queue manager data from the unrecoverable queue manager can be lost. The amount of lost data is dependent on how recently the backup queue manager was last updated. The more recently the last update, the less queue manager data loss.

Note: Even though the queue manager data and log files are held in different directories, make sure that you back up and restore the directories at the same time. If the queue manager data and log files have different ages, the queue manager is not in a valid state and will probably not start. Even if it does start, your data is likely to be corrupt.

Procedure

1. Run the strmqm control command to activate the backup queue manager as shown in the following example:

   strmqm -a BackupQMName
   

   The backup queue manager is activated. Now that it is active, the backup queue manager can no longer be updated.
2. Run the strmqm control command to start the backup queue manager as shown in the following example:

   strmqm BackupQMName
   

   IBM MQ regards this as restart recovery, and uses the log from the backup queue manager. During the last update to the backup queue manager, replay will have occurred, therefore only the active transactions from the last recorded checkpoint are rolled back.
3. Restart all channels.
4. Check the resulting directory structure to ensure that we have all the required directories. For more information about IBM MQ directories and subdirectories, see Plan file system support.
5. Make sure that we have a log control file as well as the log files. Also check that the IBM MQ and queue manager configuration files are consistent so that IBM MQ can look in the correct places for the restored data.

Results

If the data was backed up and restored correctly, the queue manager now starts.