From: Carlos H. Reimer <carlos.reimer@opendb.com.br>
To: david_list@boreham.org
Cc: pgsql-performance@postgresql.org
Subject: RES: Bad iostat numbers
Date: Fri, 1 Dec 2006 12:29:11 -0200
Message-ID: <PEEPKDFEHHEMKBBFPOOKOEIEDKAA.carlos.reimer@opendb.com.br> (raw)
In-Reply-To: <456F9262.4080207@boreham.org>
Hi,
I´ve taken a look in the /var/log/messages and found some temperature
messages about the disk drives:
Nov 30 11:08:07 totall smartd[1620]: Device: /dev/sda, Temperature changed 2
Celsius to 51 Celsius since last report
Can this temperature influence in the performance?
Reimer
> -----Mensagem original-----
> De: David Boreham [mailto:david_list@boreham.org]
> Enviada em: sexta-feira, 1 de dezembro de 2006 00:25
> Para: carlos.reimer@opendb.com.br
> Cc: pgsql-performance@postgresql.org
> Assunto: Re: [PERFORM] Bad iostat numbers
>
>
> 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: carlos.reimer@opendb.com.br, david_list@boreham.org
Subject: Re: RES: Bad iostat numbers
In-Reply-To: <PEEPKDFEHHEMKBBFPOOKOEIEDKAA.carlos.reimer@opendb.com.br>
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