Linux: Restoring the previous maintenance level on IBM MQ

How to remove updates and restore the previous maintenance level using RPM. The following instructions apply to all Linux® platforms, including Ubuntu.

Before you begin

If you are running on a server with multiple IBM® MQ installations, you must identify the installation. Make sure that the commands you enter run against the correct installation; see setmqenv.

About this task

When maintenance is applied, the original versions of replaced files are saved to allow the updates to be removed if necessary. To restore the previous maintenance level, run an Red Hat Package Manager, RPM, uninstall command for all the packages that were updated by the maintenance package as follows:

Procedure

Log in as a user in group mqm.
Stop all applications using the IBM MQ installation.
If you use the MQ Managed File Transfer (MFT) component, ensure that any MFT agents have finished all of the file transfers that they were engaged in. There should be no incomplete transfers associated with the agents, and their SYSTEM.FTE.STATE queues should contain no messages.
End all the activity of queue managers associated with the IBM MQ installation.
1. Run the dspmq command to list the state of all the queue managers on the system.
  Run either of the following commands from the installation that you are updating:
```
dspmq -o installation -o status
dspmq -a
```
  dspmq -o installation -o status displays the installation name and status of queue managers associated with all installations of IBM MQ.
  
  dspmq -a displays the status of active queue managers associated with the installation from which the command is run.
2. Run the MQSC command, DISPLAY LSSTATUS(*) STATUS to list the status of listeners associated with a queue manager.
```
echo "DISPLAY LSSTATUS(*) STATUS" | runmqsc QmgrName
```
3. Run the endmqm command to stop each running queue manager associated with this installation.
  The endmqm command informs an application that the queue manager it is connected to is stopping; see Stopping a queue manager.
  - For the maintenance to proceed, applications must respond to an endmqm command by disconnecting from the queue manager and releasing any IBM MQ libraries they have loaded. If they do not, you must find another way to force applications to release IBM MQ resources, such as by stopping the applications.
  - You must also stop applications that are using the client libraries that are part of the installation. Client applications might be connected to a different queue manager, running a different installation of IBM MQ. The application is not informed about queue managers in the current installation being shut down.
  - Any applications that continue to have IBM MQ shared libraries from the installation loaded prevent you applying IBM MQ maintenance. An application might disconnect from a queue manager, or be forcibly disconnected, but keep an IBM MQ shared library loaded.
  Note: The topic, Applying maintenance level updates to multi-instance queue managers, describes how to apply maintenance to a multi-instance queue manager. A multi-instance queue manager can continue to run on one server, while maintenance is applied to another server.
4. Stop any listeners associated with the queue managers, using the command:
```
endmqlsr -m QMgrName
```
Log in as root, or switch to the superuser using the su command.
Run the rpm command to find out which packages are installed on your server.
Enter the following command:
```
rpm -qa | grep MQSeries
```
Note: If you are using Ubuntu, add the --force-debian attribute.
```
rpm --force-debian -qa | grep MQSeries
```
Using the example given in Linux: Applying maintenance level updates on IBM MQ, returns:
```
MQSeriesRuntime-V.R.0-0
MQSeriesSDK-V.R.0-0
MQSeriesServer-V.R.0-0
MQSeriesRuntime-Uxxxx-V.R.0-1
MQSeriesSDK-Uxxxx-V.R.0-1
MQSeriesServer-Uxxxx-V.R.0-1
```
where V is the version number and R is the number of the Release.
Run the rpm command to remove all the updates applied at level 1.
Enter the following commands:
```
rpm -ev MQSeriesRuntime-Uxxxx-V.R.0-1 MQSeriesSDK-Uxxxx-V.R.0-1
MQSeriesServer-Uxxxx-V.R.0-1
```
where V is the version number and R is the number of the Release.
Repeat step 5 to check that the ptf packages have been removed, leaving only the original install packages:
```
MQSeriesRuntime-V.R.0-0
MQSeriesSDK-V.R.0-0
MQSeriesServer-V.R.0-0
```
where V is the version number and R is the number of the Release.

What to do next

For further information on using RPM to install software packages, see your Linux documentation.