Failover for Mail Server System
Im currently running a mail server using RHEL 4 (sendmail/dovecot).
For high availablity I need to configure some failover mechanism in case the server goes down.
I plan to do this using a separate server running Windows 2003. The idea is in case the the linux server goes down, all mail services immediately become available on the Windows.
I feel doing an automatic failover may be complex so for a start Im looking for a manual failover (really, just a backup server).
My problem is how to get all incoming messages directed to both the Linux and Windows (possibly at the Sendmail level). If this is done, then I feel what I need to do in case the linux goes down is to simply change the IP address of the Windows to that of the Linux. Obviosuly, this assumes that the user configs (names/passwords) both on the linux and windows are the same. This could be a lot of work considering a user base of over 200 who change their usernames/passwords frequently.
Could there be a better way of doing it.
Im relatively new to linux.