On Wed, 14 Feb 2007 07:22:55 +0200 Neil Thompson <abraxis at telkomsa.net> wrote: > Hi all, > > As the resident Linux guru, I've just been tasked with costing a webmail setup > for about 600 000 users. They each have 10MiB (small, I know) mailboxes. The > current setup has about 40 million web page accesses per month. > > Has anyone here any experience with this kind of thing? If so, any pointers as > to software and hardware used, and any other advice would be appreciated. Been there, done that. If your webmail of choice uses imap to access mailboxes (all php based do), then your primary concern is I/O of your mail storage and your imap server. Cyrus does well on many mail boxes (see fastmail.fm and their blogs for nice example). For storage choose appropriate SAN (i recommend fibrechannel) with many spindles (the more, the better the responsiveness) and nice ammount of write cache. We have about 350k users on 1Tb single cyrus instance, but that turned out to be a bit of a pain when memory error shits down on your filesystem and fsck takes almost a day to fix it. So I'd recommend you to split your users across many smaller cyrus volumes (fastmail.fm did that too) that can be fscked independently in a reasonable amount of time. For filesystem choice, nothing beats reiserfs in maildir like stoarge scenarion. If you want to know more, just ask. -- Jure Pečar http://jure.pecar.org