RES: Bad iostat numbers

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(at)boreham(dot)org]
> Enviada em: sexta-feira, 1 de dezembro de 2006 00:25
> Para: carlos(dot)reimer(at)opendb(dot)com(dot)br
> Cc: pgsql-performance(at)postgresql(dot)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).
>
>
>
>