Here is the mail from Steve Sturgess from a few weeks ago on the matter.
-------- Original Message --------
Subject: Re: [Fwd: [Snort-users] snort-2.6rc1 using a lot of memory]
Date: Wed, 19 Apr 2006 09:30:05 -0400
From: Steven Sturges [steve.sturges at sourcefire.com]
To: nkrukauskas at gmail.com
CC: Jennifer Steffens [jennifer.steffens at sourcefire.com], snort-beta
at sourcefire.com, snort-users at lists.sourceforge.net
References: <444638F8.2070304@sourcefire.com>
Nerijus--
As noted in the RELEASE.NOTES, there was a change in the
default pattern matching engine from Wu-Manber to standard
Aho-Corasick which is faster but consumes more memory.
This effectively replaced an implicit config of
config detection: search-method mwm
with
config detection: search-method ac
The Aho-Corasick implementation in snort has a few different
memory models, standard, full, banded, sparse, and sparse
banded. The sparse and spare-banded ones consume much less
memory... To use them, add a snort.conf line, as desired,
for example. Wu-Manber is being deprecated in the next
release.
config detection: search-method ac-sparsebands
There is also the lowmem method, which is slow, but uses
very little memory.
Cheers.
-steve
Richard Bejtlich wrote:
Hello,
Has anyone else tried Snort 2.6.0RC1 on FreeBSD 6.0?
uname -a
FreeBSD orr.taosecurity.com 6.0-SECURITY FreeBSD 6.0-SECURITY #0: Tue
Apr 18 08:56:09 UTC 2006
root@builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC i386
I've tried compiling it with 3 different variations, namely:
--enable-ipfw --enable-perfprofiling --enable-dynamicplugin
--enable-perfprofiling --enable-dynamicplugin
--enable-dynamicplugin
and then running it like so:
snort -i <interface> -c etc/snort.conf -l .
--dynamic-preprocessor-lib-dir
/usr/local/lib/snort_dynamicpreprocessor
snort.conf is literally the unaltered snort.conf in the distro. Rules
are the current snapshot.
All three different compilations result in Snort using 183 MB of
memory while running. This is over twice what Snort 2.4.4 occupies on
the same hardware. I'd just like to know if this is normal, perhaps
as a result of the dynamic preprocessors?
Does anyone have a different experience?
BTW I tried this on two different i386 systems -- same results.
Thank you,
Richard
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-------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
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