[Ocfs2-users] mailcluster advice?

[Brian Kroth]

I'm working on setting up a mail cluster (imap, pop, mx) using ocfs2.
Does anyone have any advice or experiences they'd like to share?

I've done web and video clusters before with great success, however
those were structured in a such a way that there was generally only ever
one write node active at a time and many read nodes.  Mail won't have
that feature.

It's all maildir, so there's no file locking, but one does need to be
concerned about ocfs2 lock contention.  Currently our thought is to have
one node for mx, pop, and imap each.  Ignoring pop for the moment, that
means there's potentially a source of contention on $mail_folder/new
when sendmail is pushing mail and dovecot is trying to move mail to
$mail_folder/cur.  After that imap connections should be on their own as
far as other nodes are concerned.  There may be multiple connections
from different clients to a single folder, but that's still confined to
the node serving imap, so in theory obtaining locks on the directory
should be quick.  I'm ignoring pop because the bulk of the users use
imap and those that use pop almost exclusively use pop, so the analysis
remains the same.

Thoughts?

Also, does ocfs2 support dnotify or inotify?

Thanks,
Brian