Performance of mailserevr in FreeBSD 5.4

Randy Schultz schultz at
Fri Sep 23 09:56:41 PDT 2005

On Tue, 20 Sep 2005, Deepak Naidu spaketh thusly:

-}Thanx Randy,
-}             It would be good, if I have some data of posted doc regarding this... or of 
-}your own experience. Thanx for your advise ....  

Ok.  I'm posting this to advocacy as well in case any find it useful or
at least interesting.

Here's a summation of the testing I did and the results of those tests.
As we were only looking for a few things this is far from a scientific 
analysis so FWIW.

Test background/setup:
   I wanted to test various configs to see what gave the best throughput in 
   a relay configuration for our real-time requirements, i.e. ave # of 
   recipients, ave size of each email, etc. 

   - OS's: FreeBSD 5.4 with and w/o softupdates, Fedora Core 3, Fedora Core 4.
     The FC installations used ext3 for the filesystems.  I wanted to try
     with Reiser but ran out of time.
   - Sink systems simply threw everything to /dev/null.  We had multiple sink
     systems to ensure they were never a chokepoint.  
   - Source systems used fbsd's postal package as:
         postal -m 11 -p 4 -c 2 d3 usernames -
     where usernames contained 2 and 3 usernames.  No significant 
     difference was found using 2 or 3 usernames.
   - Test relay was a dual-proc 800 MHz system PC with 1 GB RAM and the 
     entire system on 1 5400 RPM drive.  (I know - nobody would ever run
     a mail server with /var/spool on the root drive but we were really
     just looking for difference percentages, not max throughput and had 
     some old systems lying around... ;)
   - All installs were default installs.  I thought about tweaking this or
     that, e.g. postfix has some notes on things to do for high-volume
     installations that we didn't do.  I wanted out-of-the-box as much as
     possible.  Tweaking can quickly turn into a slippery slope of just 1 
     more here and 1 more there.  I figured we can tweak all we want for
     more specific needs as they arise.
   - The versions of sendmail and postfix were whatever was current stable
     in June, compiled locally with default build instructions.

So, given all that, here's the #'s I came up with.  

   Linux:    47,000 emails/hr
   FreeBSD:  66,000 emails/hr

   this is about a 40% increase in throughput.

   Linux:     86,000 emails/hr
   FreeBSD:  223,000 emails/hr

   this is about a 260% increase in throughput.

The above data is for FC4 and FBSD 5.4 with softupdates enabled.  My 
apologies but I can't find the notes for FC3 and FBSD w/o softupdates.  FC4 
was faster but not by much, and by about the same % for sendmail and postfix.
Softupdates showed a similar pattern(as expected) - not as fast as with 
softupdates.  IIRC the data for postfix/fbsd w/o softupdates was still
around 190k emails/hr(this is from memory so take it with a grain of salt).

I was amazed at the difference with postfix.  Whatever Mr. Venema did inside
postfix really works well on fbsd.  Even though I can't find the #'s I 
remember my amazement that fbsd w/o softupdates still smoked FC4 when using 

Pls remember this is far from a scientific analysis.  Your mileage will vary
in many ways.  I would recommend doing your own tests with your own criteria.

 Randy    (schultz at  715-726-2832     email bodhisattva     <*>

 "There is no fire like passion, there is no shark like hatred,
 there is no snare like folly, there is no torrent like greed."

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