Re: System Load analyze

[Peter Bauer <peter(dot)bauer(at)apus(dot)co(dot)at>]

Hi Greg,

Am Mittwoch 28 November 2007 schrieb Greg Smith:
> On Sat, 24 Nov 2007, Peter Bauer wrote:
> > top shows that the CPUs are at least 80% idle most of the time so i
> > think there is an I/O bottleneck.
>
> top also shows that you're never waiting for I/O which is usually evidence
> there isn't an I/O bottleneck.  You passed along most of the right data,
> but some useful additional things to know are:
>
> -Actual brand/model of SCSI controller
> -Operating system
> -What time interval the vmstat and iostat information you gave were
> produced at.

here are the hardware specs:
2x POWEREDGE 2850 - XEON 3.0GHZ/2MB, 800FSB
2048MB SINGLE RANK DDR2
73 GB SCSI-Disk , 15.000 rpm, UL
PERC4E/DI DC ULTRA320 SCSI RAID, 256MB

Its Debian sarge with kernel 2.4.26.050719-686 #1 SMP.

vmstat and iostat were running with 1 second intervals.

> I agree with Scott that checkpoints should be considered as a possibility
> here.  I'd suggest you set checkpoint_warning to a high value so you get a
> note in the logs every time one happens, then see if those happen at the
> same time as your high load average.  More on that topic and how to adjust
> the background writer if that proves to be the cause of your slowdown is
> at http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm
>
> --
> * Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD
>
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thank you,
Peter




-- 
Peter Bauer
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