On Mon, Jan 28, 2002 at 01:03:06PM +1100, Scott Stavretis wrote:
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| Hello,
|
| I am after some advise. What is one to do when they have to many
| users on a single server (using one domain) and would want to split
| mail across multiple servers? What do the larger ISP's do?
|
| I've been thinking about this and believe the best way to do it
| would be based on the first character in the local-part of the
| e-mail address/username
|
| i.e. mail to a*@??? to j*@??? goes to server 01
| k*@??? to z*@domain .com goes to server 01.
|
| To do this I presume you would need at least three servers 1 being a
| forward machine and the other two being physical mail hosts.
Why not just have 2 MX records and 2 mail hosts for your domain? Or
use round-robin DNS for the MX record? Some domains, like hotmail,
use the former. I don't know if the latter works for MX, but
www.debian.org and http.us.debian.org use it for A records (the
purpose is to load-balance amongst the mirrors).
(just to show what hotmail does:)
$ host -t mx hotmail.com
hotmail.com MX 5 mx06.hotmail.com
hotmail.com MX 5 mx07.hotmail.com
hotmail.com MX 5 mx08.hotmail.com
hotmail.com MX 5 mx09.hotmail.com
hotmail.com MX 5 mx10.hotmail.com
hotmail.com MX 5 mx11.hotmail.com
hotmail.com MX 5 mx12.hotmail.com
hotmail.com MX 5 mx13.hotmail.com
hotmail.com MX 5 mx14.hotmail.com
hotmail.com MX 5 mx15.hotmail.com
hotmail.com MX 5 mx01.hotmail.com
hotmail.com MX 5 mx02.hotmail.com
hotmail.com MX 5 mx04.hotmail.com
hotmail.com MX 5 mx05.hotmail.com
| Obviously I would need a POP3 splitter of some sort, any
| recommendation would be good.
| Then I would need exim to be able to deliver mail based on
| $local_part somehow? This is the tricky bit I see.
|
| Any idea's/suggestions are welcome.
You could split up /var/spool/mail into a hierarchy based on address
or something, then share the directory via NFS so that all machines
use the same disk. Then it doesn't matter which host handles the
request for which address. If your setup is big enough for disk speed
to be an issue, get a bunch of SCSI disks and hardware RAID to do
striping and mirroring (the former for performance the latter for
reliability) or get a dedicated disk server with enough performance
(the SE department at school has one; it's a really neat device).
(BTW the only mail server I manage has just 1 user, I have no hands-on
experience doing that sort of stuff)
-D
--
A kindhearted woman gains respect,
but ruthless men gain only wealth.
Proverbs 11:16
