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On Fri, 2006-01-13 at 12:44 -0800, Todd Lyons wrote:
> I don't know that I'd feel all that comfortable about syncing either
> one:
> mbox - This could end up with a corrupted mbox file since it's all one
> big long file.
> maildir - Guaranteed that you won't end up with any filename conflicts
> since the hostname is used in the filename, but there are some shared
> files, such as the quota or subscribed files. Those files could easily
> get out of sync.
Indeed they can (says someone long since burnt, not exactly by rsync,
but by some other methods of attempting to sunc mailboxes...).
I now use NetApp filers on which my maildirs live, and I have multiple
IMAP/POP (and Horde/IMP webmail) servers living behind a pair of LVS
directors. Using maildir format [0], I export the mailboxes via NFS to
the frontend servers and it works a treat - generally because maildir
saves files using filenames derived from the hostname, so the frontend
servers don't hit race conditions when trying to manipulate files.
If you need really (and I mean _really_) high NFS transaction rates and
fault-tolerance, I can't recommend the NetApp kit highly enough. If you
don't, then other options - cheaper ones! - are (for example) high-end
Intel-based IBM, Dell, HP/Compaq etc. servers with large hardware RAID
arrays for redundancy. You'd have to address the various benchmarks
according to your means, but there's a price point for every pocket
somewhere.
[0] for the inevitable extra question: Exim v4.x for the (E)SMTP server,
Courier IMAP server for IMAP & POP; all backended with MySQL for
mailbox/address lookups and POP/IMAP/SMTP authentication.
Graeme
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