Hello,
On Mon, 25 Jun 2007 10:10:00 -0400 (EDT) "Scott Zahn" <scott@zahna.com> wrote:
Currently where I work we use qmail.
My condolences. The worlds most patched PoS (software, really, I mean software) by the biggest ego in the business.
Every time a message is delivered, qmail seems to walk through the user's entire maildir in order to calculate quota usage.
That doesn't seem right, not if it is using maildirsize maildir++ quotas, see: http://www.inter7.com/courierimap/README.maildirquota.html
The worst case scenario would be a full mailbox, which would trigger a full recalculation every 15 minutes (Exim does it every 20 minutes). This recalculation is part of the specification, of course a smartly designed mail system will (with a few scripts and a database of sorts) prevent delivery attempts (and thus recalcs) to full mailboxes.
So the first thing to check is if these mailboxes are perma-full or if they get so much activity that the maildirsize quickly grows to the 5k size that triggers a recalculation. If neither is the case, then yes, qmail is your enemy (surprise, surprise). Or if you are delivering with something else, that is the culprit then.
Delivering messages simultaneously to just a few users who are allowed large maildirs (1-2GB) will bring our servers to their knees. Which brings me to dovecot. I use dovecot whereever I can, but haven't yet needed to set up quotas. I would like to migrate my servers at work to use dovecot, but have a few questions regarding quotas. Could someone explain how dovecot calculates quota usage on mail delivery? Also, is there anyone here on the list that uses quoatas on large maildirs (>=2GB)? How well has it worked for you?
Again, having to recalculate the quota eventually is part of the specification. If your hardware (I/O) can stand the infrequent recalculations working maildir++ quota requires you are gold.
Regards,
Christian
Christian Balzer Network/Systems Engineer NOC chibi@gol.com Global OnLine Japan/Fusion Network Services http://www.gol.com/