Recomendations for a 15000 Cyrus Mailboxes

[Zachariah Mully]

On Tue, 2007-04-10 at 06:56 -0500, Nestor A. Diaz wrote:
> Hello People,
> 
> I am a proud cyrus user and fan, right know i need o implement a 15K 
> users cyrus mailstore, since i have been using cyrus for an average  400 
> users mailstore, i will like to hear comments for setting up a cyrus for 
> a 15K users.
> 
> I currently have a  ' postfix / postgresql / cyrus-sasl / cyrus ' 
> production server working for more than two years without problems, and 
> i am going to replicate the same configuracion, however since i am going 
> to have a  huge  space  for mail  and people are going to use a lot of 
> space, aprox. 50 MB per user, i will like to hear some comments about 
> what should be the best  (cyrus / pop3 / imapd) configuration, i have 
> read on the mail list some configuration that fastmail.fm use, including 
> pop3, imap proxies and multiple instances of cyrus, but i like to see 
> more comments about that.
> 
> These are the plans: (comments on every number will be apreciated)
> 
>    1. Linux LVM over a 600 GB RAID 10 ( 4 x 300 GB)
>    2. Which filesystem seems to be the better ? ext3 ? xfs ? reiserfs ?
>    3. Which options to format the filesystem ? acording to the chosed
>       filesystem
>    4. Which pop3 / imap proxy to use ?
>    5. Single instance or multiple instances of cyrus ? taking in mind
>       that there should be the option to recover a mailbox or some mail
>       of a mailbox without having to shut down the whole cyrus system.
>    6. Best way to perform backups ? LVM snapshots ? shutting down some
>       cyrus partitions ? RAID10 hot swap ?

Sid-
	Search the archives for any posts from the good folk over at FastMail.
I'm pretty sure that in the past couple of months Bron at FastMail dropped
some serious knowledge about how to set up enormous mail systems, and
though they might not necessary apply to you, they are good to keep in
mind. One recommendation that I remember in particular, especially
because I'm dealing with the problem on one of my servers, is to
partition your data as recovery of large RAIDs/partitions is a pain, and
can take forever even on a fast system. 
	Also, remember that backup is not critical, restore is. If I had a
choice, I would always rather go with a cold replicate than rely on tape
or snapshots as the first tier of recovery. That is, if I had the money
for it ;)

Z

-- 
Zachariah Mully
Director, Systems and Networks
SmartBrief, Inc.
zmully at smartbrief.com
p: 202-737-5500
f: 202-737-7577