Hi,
I have two load-balanced dovecot servers using a single NFS mount. The version is 1.2.11. I chose this so that if one server goes down the other will take up the load, and if my load is too much for one server I just have to add more identical servers. It works, but I wish to move to SAN storage because the NFS server is exhibiting irregular performance. (I spent a lot of time with tcpdump to check that it wasn't NFS locking problems). Performance is very important to me, not in the sense of many users but in the sense of quick response time, since the main use is as a webmail backend.
That means that instead of load-balancing connections between servers I will have to partition users between servers (all on one to begin with) and direct users to the corresponding server.
I expected to use perdition, but when reading up on that I found imapproxy, which could be interesting for performance reasons, and also that dovecot has an included proxy, and that its performance is better than perdition. However on http://wiki.dovecot.org/HowTo/ImapProxy the feature "IMAP/POP3 server with proxy feature" is noted as "This model is still a bit unfinished in current code."
Is this still true? There's also a general note that "This page was written quite a long time ago and may not match reality anymore" . . .