Excuse the basic nature of the question, I've zero experience with regards to this and I'm just looking for a little clarity...

When using serviceguard for a failover from one machine to another, what doesn't get taken from one machine to the other? For example, I was told that OS users and things like /opt don't get carried across. Is this true? Of so, is there anywhere I can get a simple overview of this? I've found the docs on the HP site to be a bit impenetrable, and not explicitly stating what I want to know. I ask because I'm in a situation where some software needs the failover is being set up for needs the OS users as well as certain bits in /opt, /etc and if these don't get taken over as I've been told then that seems a bit pointless.