[Dovecot] More Benchmarks, and a question about indexing

[Rick Johnson]

Anthony Wendell Kay wrote:
> Hi,
> 
> We are thinking of converting to Dovecot to lighten our I/O load. I have done
> some performace tests comparing UW-IMAP to Dovecot when using mbox format if
> anyone is interested. They primarily examine the I/O improvements that can be
> gained from using Dovecot over UW when staying with mbox format:

Perhaps I just missed something - but what was used to benchmark? IMHO? 
I'm curious as I wouldn't mind trying to benchmark (in general) my 
Maildir setup. Granted, I don't have an mbox comoparison anymore for the 
same machine, but it would be an interesting one none the less.

> Anyway, we are stuck with the mbox format for the forseeable future, and I
> noticed how hard hitting Dovecot is on initial access to a large mailbox, so we
> need a way to pre-create some of those indexes. I saw in the docs that such an
> indexer has been planned, but does anyone have a hack for doing it now?

IMHO, it's not a difficult transition as long as you have a good sized 
window to make the swap (depending on number of users and speed of the 
hardware), and your MDA is capable of switching easily (Procmail is). I 
found/wrote a couple of scripts to facilitate the transition, which were 
recently sent to this list. Perhaps there are other (political?) reasons 
for sticking w/ mbox, however.

Myth dispelling time: For those who are concerned about inode usage with 
Maildir, my 110GB available RAID is 21% used on disk space with mail, 
but only 4% used for inodes. It seems to me I'll run out of space long 
before I run out of inodes with my user's present usage. This is for 150 
users, approx 60% of which use IMAP and 1/2 of them again store 
significant amounts of mail on the server. Some of my largest users have 
upwards of 30,000 messages (packrat managers).

-Rick
-- 
Rick Johnson, RHCE #807302311706007 - rjohnson at medata.com
Linux/Network Administrator - Medata, Inc. (from home)
PGP Public Key: https://mail.medata.com/pgp/rjohnson.asc