On Fri, September 22, 2006 5:05 am, Robin Elfrink robin@15augustus.nl said:

-How many mailboxes do you run on one backend?

The limit on the backend is disk. We're comfortable at about 10,000 mailboxes per 7200 RPM SATA drive. The more disks you put on each backend server, the more mailboxes each server can handle.

-Do you have any anti-spam/virus running on them or is that done earlier?

Yes. Currently 17 servers doing just filtering. These run Postfix, SpamAssassin, Policyd, ClamAV.

-Have you ever used perdition and if so, how does dovecot as a proxy compare to that?

Yes. Perdition requires a process per connection though, so it does not scale well. With Dovecot's proxy (and also the nginx proxy, http://sysoev.ru/en/) individual processes can handle multiple connections, and takes advantage of epoll for network events which is ideal for handling large numbers of idle IMAP connections. With Perdition we'd run at 2000 connections per server, with Dovecot we haven't it a peak yet, but expect to peak at around 15,000 - 25,000 connections per proxy server. Obviously the bigger the box, the more connections it can handle.

-Do you mind me asking these questions?

Nope. Ask away. If I can't answer it I'll tell you.

Bill