reducing memory used by Mailscanner

Bryan Guest bryan.guest at
Tue Apr 20 16:41:09 IST 2010


This is a follow up to a previous post about the resident size of 

I have added a new incoming MailScanner blade to my setup.  It's a Sun X2200 
with 4Gb of RAM.  My previous two blades are Sun V20Z machines also with 4Gb 
of RAM.  All Machines are running Redhat ESv4

I am running the latest Mailscanner and ClamAV-SA package on the new 
machine.  The resident size of MailScanner is 170Meg on the new machine. 
(It's 76M on the best running machine).

I am interested in how I can pair down the resident memory size used by 
MailScanner or improve performance/reduce load average.

My fundamental problem is that even though the two V20Z's are running the 
same older version of MS (4.56.8), one runs hotter (higher load average) 
then the other.  And the newer X2200 machine runs hotter still.

IE:  the one V20Z is at load average 0.5.  The second is at 1.32.  The X2200 
with the latest MS is at 3.57.  Note that these are in round-robin rotation 
behind an L4 switch.

I have adjusted the number of processes as best I can to avoid swapping out 
based on the resident size of MS. But randomly it seems the load average 
will shoot up on the second V20Z or the X2200.  And by shoot up, I mean that 
it goes over 25 (~30-50 sometimes) and sendmail stops accepting mail.

Can anyone assist me in shedding any light on why one blade of two identical 
boxes runs hotter, and why a newer machine running the latest MailScanner 
runs even higher.

Alternately I would be supremely receptive to tips on how to bring down the 
load on these servers.  Note, I am running the log and spool partitions with 
noatime, and syslog with - on the logs.

For clarification, we are not using SpamAssassin or the Bayes functionality 
on these blades.  We employ MailScanner strictly for policy enforcement and 
virus scanning and use an external spam filter.

If I install a fresh Mailscanner install, and the ClamAV/SA package but halt 
the install before it compiles SA, will this reduced the resident size of 

All the best regards to everyone, and thanks in advance,

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