Removing maintenance on Linux Ubuntu using apt

From IBM® MQ 9.4.0, you can use the apt command to remove maintenance from an IBM MQ installation on Linux® Ubuntu systems.

Before you begin

When you use apt the IBM MQ installation that includes the maintenance level is replaced with an installation at an earlier level of IBM MQ. Therefore, you must decide which level of IBM MQ you want to revert to. Then you must ensure that the installation files for the earlier level of IBM MQ are available on the system.

About this task

You can use apt only to roll back the fix pack level of your installation. You cannot use the command to roll back the version, release, or modification level of your IBM MQ installation. To roll back the version, release, or modification level of your installation, you must uninstall the higher level and then install the earlier level that you require. However, any queue managers that are running at a higher version or release of IBM MQ cannot then be started on the earlier version or release. For more information, see Queue manager migration.

Procedure

Complete the following tasks:
1. Stop all your IBM MQ applications.
  
  If you use the Managed File Transfer (MFT) component, ensure that any file transfers that MFT agents are engaged in are completed. The SYSTEM.FTE.STATE queues must contain no messages.
2. Stopped the mqweb server by using the endmqweb command.
3. Stopped your listeners by using the endmqlsr command.
4. Stopped all your queue managers by using the endmqm command.
  If a queue manager is part of a cluster, you must suspend the queue manager before you stop it. For more information, see Maintaining a queue manager in a cluster.
5. Backed up your data.
  For more information, see Backing up and restoring queue manager data.
Log in as root, or switch to the root user by using the su or su - commands. Alternatively, you can use the sudo command to run commands as the root user, if your system administrator gave you the privilege to do so.

To use the sudo command, add sudo before the command that you want to run. For more information about the su and sudo commands, see Exploring the differences between sudo and su commands in Linux on the Red Hat® website.
Set your current directory to the location of the earlier level installation files. The location might be a network location, or a local file system directory.
Open the IBM_MQ.list file from the /etc/apt/sources.list.d directory.
Add the following line to the end of the IBM_MQ.list file:
```
deb [trusted=yes] file:installationFileLocation ./
```
where installationFileLocation is the directory where the earlier level IBM MQ installation files are located.
Refresh the repository index by using the following command:
```
apt-get update
```
Remove the IBM MQ maintenance level by using the following command:
```
apt-get -y --allow-downgrades install "ibmmq-*"=version
```
where version specifies the version of IBM MQ that matches the earlier level IBM MQ installation files that are in the current directory.
Use the dspmqver command to verify that the level is as expected:
```
dspmqver
```