From: David Boreham <david_list@boreham.org>
To: carlos.reimer@opendb.com.br
Cc: pgsql-performance@postgresql.org
Subject: Re: Bad iostat numbers
Date: Thu, 30 Nov 2006 19:24:34 -0700
Message-ID: <456F9262.4080207@boreham.org> (raw)
In-Reply-To: <PEEPKDFEHHEMKBBFPOOKKEHCDKAA.carlos.reimer@opendb.com.br>
References: <PEEPKDFEHHEMKBBFPOOKKEHCDKAA.carlos.reimer@opendb.com.br>
Carlos H. Reimer wrote:
>
>
> avg-cpu: %user %nice %system %iowait %idle
>
> 50.40 0.00 0.50 1.10 48.00
>
>
>
> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s
> avgrq-sz avgqu-sz await svctm %util
>
> sda 0.00 7.80 0.40 6.40 41.60 113.60 20.80
> 56.80 22.82 570697.50 10.59 147.06 100.00
>
> sdb 0.20 7.80 0.60 6.40 40.00 113.60 20.00
> 56.80 21.94 570697.50 9.83 142.86 100.00
>
> md1 0.00 0.00 1.20 13.40 81.60 107.20 40.80
> 53.60 12.93 0.00 0.00 0.00 0.00
>
> md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00
> 0.00 0.00 0.00 0.00 0.00 0.00
>
>
>
> Are they not saturated?
>
>
>
> What kind of parameters should I pay attention when comparing SCSI
> controllers and disks? I would like to discover how much cache is
> present in the controller, how can I find this value from Linux?
>
>
These number look a bit strange. I am wondering if there is a hardware
problem on one of the drives
or on the controller. Check in syslog for messages about disk timeouts
etc. 100% util but 6 writes/s
is just wrong (unless the drive is a 1980's vintage floppy).
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To: pgsql-performance@postgresql.org
Cc: david_list@boreham.org, carlos.reimer@opendb.com.br
Subject: Re: Bad iostat numbers
In-Reply-To: <456F9262.4080207@boreham.org>
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