dovecot@corwyn.net wrote:
Currently I have a mail server running postfix and dovecot with users in mysql. I have Outlook (blich) clients checking IMAP mail on the server. I'd like to build some fault-tolerance into that system in case I have hardware failure.
I've read through: http://wiki.dovecot.org/MailLocation/SharedDisk but I feel I need more information. My basic understanding is that I'll need 2 clustered systems running with shared disk space and shared IP. Performance/load-balancing isn't an issue for me, it's just fault-tolerance that I'm worried about.
I found a nice long doc for Cyrus IMAP (http://cyrusimap.web.cmu.edu//ag.html), anything similar for dovecot?
You're probably looking for Dovecot replication, which as far as I'm aware, has not made itself known in a functional form yet. I really want to see master/master replication.
I was working on coming up with something myself in an active/standby setup using DRBD. If the heartbeat dies, DRBD on the standby fires up its Dovecot and takes over. Vice-versa for the primary recovering: shut down standby and start primary. It's not totally transparent because it would drop all active connections during the switch. In practice, I find that nobody notices unless it happens multiple times in a row or they happened to be in the middle of a long IMAP command.
~Seth