Websphere Message Broker Fixpack installation - Do backup before it

It is nice to know that IBM invested some thinking in the broker fix pack installation process, or maybe not.
The installation most of the time works fine, the problem is if something go wrong and you want to rollback the installation process.

The problem is that the only fix pack that you can uninstall are those of the toolkit. You can't uninstall any runtime fix packs.
If for some reason the broker or config manager fail to start post the fixpack installation than you probably would need to reinstall all server components.
With my great fixpack installation I encountered a nice feature, the installation massed up the jre library thus the components failed to start. I succeeded to fix it by copy the jre library from other working server.

It's very strange, really.

So before you install I suggest to backup the server, make a snapshot/image.