OSEC

Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email hr@neohapsis.com
 
Subject: Re: large postfix installations?
From: Brad Knowles (blkskynet.be)
Date: Mon Apr 03 2000 - 13:23:13 CDT

At 1:14 PM -0400 2000/4/3, Jeff Wasilko wrote:

> I'm looking for something more lightweight to enhance our
> scalability. Currently, we can push about 400,000 to 500,000
> messages per day through a Ultra 2/E250 (with the queues on a
> caching storage array). We are moving to 4 cpu E420Rs and our
> initial tests show that we could do about 2 Million messages
> per day on that platform.

        Well, if you follow the suggestions in my paper at
<http://www.shub-internet.org/brad/papers/sendmail-tuning/>, you
should be able to get a single system that can scale to handle at
least a million messages per day (or quite a bit more), on much less
powerful hardware than you've got now -- and by using sendmail, and
not postfix.

        If you used postfix on that same hardware, you should be able to
get considerably more speed out of that you can with sendmail.

        Remember -- mail is not CPU bound, it's I/O bound, specifically
disk I/O bound. In particular, the single most critical thing to
eliminate is synchronous metadata updates.

        In your case, I think you'd be much better off switching
filesystems to UFS logging or Veritas VxFS than spending extra money
on the hardware.

        Better yet, switch to FreeBSD and use softupdates, where you
should see a factor of five to ten performance improvement. 

--
   These are my opinions -- not to be taken as official Skynet policy
======================================================================
Brad Knowles, <blkskynet.be>                || Belgacom Skynet SA/NV
Systems Architect, Mail/News/FTP/Proxy Admin || Rue Colonel Bourg, 124
Phone/Fax: +32-2-706.13.11/12.49             || B-1140 Brussels
http://www.skynet.be                         || Belgium