I have a mail server on Fedora 8. I would like to have a mirror to this server so that it takes over in case my server goes down

A mirror to the physical server, or a mirror as in raid1 of the hard drive? I would start with redundancy at that level, you know redundant power supply, hard drives, etc.

If.. you mean a physical machine, then you can simply re-image a new machine with the same OS (clonezilla the server if you can take it offline for a little bit), then depending on the mail server, simply do an rsync of that folder each hour or whatever you feel is a safe time not killing the i/o doing it every minute.

Just my 1st thoughts, but I would focus on getting the server part more redundant vs. a 2nd physical machine as you would still have IP issues to change etc. when a failure on the primary occurred.

I think you are looking for some sort of fail over system. The best would be http://linux-ha.org/. Moreover, you can do virtualization also using any virtualize tools available, xen, p2v etc. and create the fail over systems. But there would be issues with IP change over etc. But that should be minimal, since you have the other system ready to serve to the users :-).

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Prasanta

You can review the doc in
http://www.twinpeaksoft.com/App_email.pdf

There is detailed steps on how to set up a failsafe email server clustering.
Perhaps, that is what you are looking for.


Jerrybear