Fwd: [Mimedefang] Setting up a RAM Disk on Freebsd 6.1

Wes Peters barnaclewes at gmail.com
Wed Sep 13 21:01:40 EDT 2006

On 9/9/06, Wayne Hahn <wayne at hamilton.net> wrote:
>  Does any one have an example of how to setup a 1.5 Gig Ram
> disk on FreeBSD 6.1? I can't seem to find any good
> documentation on it.
>  I setup sendmail with Mimedefang 2.57 and Spamassassin
> 3.1.4. If I load test it and run more then 5 or 6
> concurrent email messages it eats up all of my processors
> and brings my server to its knees. I am running it on an
> AMD Athlon 64 X2 4200 with 2 Gig of ram. I am planning on
> adding more Ram if I can figure out the Ram disk.  I have
> seen wiki with setting up a Ram disk on FreeBSD but I
> believe that was for version 4.

The ramdisk probably won't help, and is almost certainly not your
problem.  I built a commercial mail security appliance on FreeBSD  5.3
with mimedefang, running on a Celeron 2.0 with 512MB ram, and it ran
10 perl slaves, postgresql, and a lot of other "stuff" with no
problem, with some careful tuning.  We did extensive testing with more
ram and a ram disk in the configuration David recommends for Linux and
it made no more than 1-3% performance difference.  Make sure your
queueing space is mounted with ufs+softupdate and noatime, of course.

The first thing you probably need to do is look at the sendmail
loadavg throttling vs. your expected loadavg.
On our appliance,  we had sendmail, the mimedefang multiplexor, virus
scanner, a commercial spam detector, and 10 perl slaves active, for a
total of 14 active processes on a loaded system.  You have to tell
sendmail it's OK to get to a loadavg of a little more than 14 before
it goes into it's backoff behavior or when you attempt to load the
system you'll get a series of spikes and ~5 minute backoffs.

Against stupidity the very gods Themselves contend in vain.
                                         Friedrich Schiller

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