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From sridhar basam <>
Subject Re: Tracking down read latency
Date Thu, 03 Feb 2011 16:57:53 GMT
The data provided is also a average value since boot time. Run the -x as
suggested below but run it via a interval of around 5 seconds. You very well
could be having i/o issue, it is hard to tell from the overall average value
you provided. Collect "iostat -x 5" during the times when you see slow reads
and see how busy the disks are.


On Thu, Feb 3, 2011 at 3:21 AM, Peter Schuller

> > $ iostat
> As rcoli already mentioned you don't seen to have an I/O problem, but
> as a point of general recommendation: When determining whether you are
> blocking on disk I/O, pretty much *always* use "iostat -x" rather than
> the much less useful default mode of iostat. The %util and queue
> wait/average time columns are massively useful/important; without them
> one is much more blind as to whether or not storage devices are
> actually saturated.
> --
> / Peter Schuller

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