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Date: Mon, 21 Jul 2014 14:04:08 -0700
From: John R Pierce <pierce@hogranch.com>
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To: pgsql-general@postgresql.org
Subject: Re: Checkpoint_segments optimal value
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On 7/21/2014 1:51 PM, Kevin Grittner wrote:
> The above might help, but I think the biggest problem may be your
> VM.  You show very low disk I/O numbers, but a pretty significant
> fraction of the time waiting for I/O.  The previously-suggested
> iostat output may help nail it down more specifically, but
> basically you seem to have a big problem with bandwidth for storage
> access.  It's pretty disturbing to see lines in vmstat output which
> show zero disk in or out, but over 10% of CPU time waiting for
> storage?!?

that would suggest to me a large number of VMs sharing a single SATA 
drive, or similar.


-- 
john r pierce                                      37N 122W
somewhere on the middle of the left coast


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