dovecot at 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