New Server Specs?

Greg Matthews gmatt at
Wed Apr 4 14:10:20 IST 2007

Paul Hutchings wrote:
> Thanks all.
> I'm not desparate to do this on the cheap, but obviously I don't want to
> be asking for company money for something that is massive, massive
> overkill even allowing for future growth/changes etc.
> Currently I'm running on an old Poweredge with a single 2.4ghz Xeon CPU
> (single core with hyperthreading) with 1gb of RAM and a single 80gb ATA
> drive (we want something that will be under warranty)
> I'm running Spamassassin on incoming mail and ClamAV on all mail with no
> OCR checks though this may be something I'll do in the future via
> FuzzyOCR.
> I'm no expert on Linux benchmarking but uptime shows "load average:
> 1.23, 1.43, 1.20".

looks like you are not stretching this box too much. With hyperthreading 
turned on, a load average of 2 would be a good indication that the 
processor was never twiddling its metaphorical thumbs. That said, 
network services are notoriously "bursty" so you need to plan for times 
of high load.

Consider software raid over hardware raid as it can often be faster and 
provided you take backups, your raid config is archived for disaster 
recovery. Also nice to have a good size disk area so that both spam and 
ham can be stored in the short term for learning/reporting. Useful too 
if you are relaying for other sites/domains and need to queue up mail 
when their servers are down. Of course, mail doesnt actually take up 
much space so you dont need a huge array of disks. We have about 5000 
active mailboxes and I'd be happy with a 50GB mirror for short term 
archive/quarantine but I'd probably over-spec by a factor of two.

As mentioned previously, buy lots of memory. A dual processor box will 
happily chew up 3-4GB of ram. Dual/quad core is /probably/ ok given that 
your processes are likely to be IO bound which should make up for memory 
controller latencies. Why not ask Sun for a loan of a T1000 machine with 
8 cores and 32 threads? I think they are still doing a no-obligation 
"try and buy" scheme for these. The list would probably be v. interested 
in your results.

> I was looking at HP originally and then I looked at Sun and noticed
> their X2100 appear to be very good VFM (and are SLES approved which
> suggests I should be able to install OpenSuse "out the box").

judging by your existing spec and LA, an X2100 will probably be fine, 
I'd be tempted to up the spec to a dual processor X2200 to really 
future-proof yourself. Again, Sun will lend you one for 60 days if you 
want to try it.


> Paul Hutchings
> Network Administrator, MIRA Ltd.
> Tel: 44 (0)24 7635 5378, Fax: 44 (0)24 7635 8378
> mailto:paul.hutchings at
> -----Original Message-----
> From: mailscanner-bounces at
> [mailto:mailscanner-bounces at] On Behalf Of Steve
> Freegard
> Sent: 04 April 2007 11:44
> To: MailScanner discussion
> Subject: Re: New Server Specs?
> Paul Hutchings wrote:
>> My question is, broadly speaking which would be best to have more of, 
>> CPU, ram, or disk subsystem?
>> I'm looking at the cheapest HP/Sun/Dell servers which tend to be SATA 
>> disks and slower dual-core CPUs but with plenty of memory slots.
> As Martin mentioned - memory is one key piece, you need to have 1Gb per 
> CPU core, then set Max Children to 5 * CPU Cores for optimum 
> performance.  Any form of swapping/paging will quickly kill performance 
> of MailScanner/SpamAssassin.
> I also always recommend buying a *decent* RAID controller with 
> battery-backed write-back cache as fast disk access is a requirement to 
> cope with busy periods and future growth and.
> Cheers,
> Steve.

Greg Matthews           01491 692445
Head of UNIX/Linux, iTSS Wallingford

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