Re: Eradic disk access during reads

[Al Boldi]

Willy Tarreau wrote:
> On Sat, Sep 17, 2005 at 01:32:53PM +0300, Al Boldi wrote:
> > Willy Tarreau wrote:
> > > On Sat, Sep 17, 2005 at 07:26:11AM +0300, Al Boldi wrote:
> > > > Monitoring disk access using gkrellm, I noticed that a command like
> > > >
> > > > cat /dev/hda > /dev/null
> > > >
> > > > shows eradic disk reads ranging from 0 to 80MB/s on an otherwise
> > > > idle system.

New synonym: eradic=erratic :)

> Denis' tool seems clearly more suited to analyse your problem.

The problem seems to be a multi-access collision in the queue, which forces a 
~50% reduction of thruput, which recovers with another multi-access 
collision.  Maybe?!

--
Al

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