FBSD 6.2 Xeon 2.4ghz CPU and high load

[Matthew Seaman]

DAve wrote:
> Good morning.
> 
> I recently upgraded our two email gateways from 4.8 to 6.2. The required 
> software was upgraded as well which consists of MailScanner and 
> Sendmail. Both had been keep up to date so it was not a jump in required 
> resources.
> 
> The issue I am seeing is that my server load, under the same traffic 
> load, has increased 4 times or more. Where previously we saw a high load 
> on the servers of 5 to 8, we are now seeing 14 to 17. Since the upgrade 
> Sendmail has begun to timeout connections.

FreeBSD 6.2 is I believe slower than 4.11 for single processor systems
and processes which pretty much run single threaded -- ie. exactly what
you're trying to run.  This would cause exactly the sort of symptoms you're
seeing.

Try 7.0 instead -- it has all of the speed at multi-threaded, multi-core
type stuff but has also regained the sort of performance levels you could
get from 4.x at the sort of tasks 4.x is really good at.  You should evaluate
SCHED_4BSD vs. SCHED_ULE for your workload.  SCHED_4BSD is still the default
in 7.0, but SCHED_ULE gives better numbers for many workloads, and it only
missed being the default in 7.0 because it hadn't had enough time to settle
into the tree before the release.  SCHED_ULE will be the default from 7.1
onwards.

	Cheers,

	Matthew

-- 
Dr Matthew J Seaman MA, D.Phil.                   7 Priory Courtyard
                                                  Flat 3
PGP: http://www.infracaninophile.co.uk/pgpkey     Ramsgate
                                                  Kent, CT11 9PW

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