[Zope] Zope Redundant Server Architecture

Hi all, This is a little bit OT. I have a Linux Server (running Zope and other CMS solutions) in production state and would like to setup a backup server for this one. What I intended to do is to mirror the existing server and, when necessary, switch to the mirror. I have done some searching on this topic and found "fake", "heartbeat" and some other tools. But I dont know which mirroring tool I should use. I need to mirror the whole server not only the Zope instance. What is the best solution in this case? Any experiences? Juergen