I'm also about to deploy such a setup for a "small" mail server. I'll use mysql replication, but only one master server will be writable.
I've used virtual machines to test, and so far so good.
My plan is to use each server in separate datacenters from the same provider and route the users by dns. I use easydns and made some tests, seems to work fine for failover.
2016-12-08 7:29 GMT-05:00 Arie Peterson <ariep@xs4all.nl>:
[…] So I believe my first step is to set up another server, on another IP, different hostname, with Dovecot and Postfix, and simply use the files from the /etc directories of the existing server to configure it (changing the IP and hostname of course).
Am I on the right track so far?
Next steps involve setting up replication with dsync?
If I have successfully setup replication between the two servers, does
SH Development wrote: this
mean users can then actually log into either server and have their “stuff” intact? So I could set up DNS failover in case the primary server fails? Would this make the setup acceptable for secondary MX as everything should sync to the primary server when it comes back online?
Yes, this is exactly what I've set up for my site a few weeks ago: the secondary server has almost exactly the same configuration as the primary one, and the secondary server is listed as MX20.
Replication with dsync works pretty smoothly. I've myself noticed one case where a mass email deletion took somewhat longer than expected to propagate to the other server. As a user, most of the time it's like you're dealing with a single server.