Senandung Mendonan mendonan@absolute-p.ath.cx writes:
I would like to perform a survey of past and current experiences with deploying and maintaining an IMAP+POP maildir cluster (e.g. Courier-IMAP), backed by Netapp filers, with > 50k mailboxes. Especially of interest is any problems you faced, how you solve them, recommended design decisions, common pitfalls, etc. You can e-mail the list or me privately, whichever you think is more appropriate.
I'd be interested in this as well, though we're doing an order of magnitude less users here. Using qmail-ldap MTA running on a handful of 1U boxes, Maildirs on the NetApp, qmail-pop3d and courier-imap for retrieval.
Only problem we see currently is under artificially heavy load to a single recipient the quota file can get hosed, qmail-local delivery hangs, NFS usage goes way up. If we kill those hung local deliveries, the mail then gets delivered so nothing lost, and the quota file gets recomputed and recreated. I expect it's because more than one box is contending for the one quota file, unlike maildir messages that are one-file-per-message and uniquely named to prevent contention.
So if others are using NetApp for Maildirs, I'd like to hear about your experiences, too.