From: Shaun Thomas <sthomas@peak6.com>
To: Greg Smith <greg@2ndQuadrant.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Cost of creating an emply WAL segment
Date: Fri, 24 Jun 2011 13:55:47 -0500
Message-ID: <4E04DDB3.8050306@peak6.com> (raw)
In-Reply-To: <4E04B8E9.3030707@2ndQuadrant.com>
References: <1308926594.2656.210.camel@lenovo01-laptop03.gunduz.org>
<4E04B8E9.3030707@2ndQuadrant.com>
On 06/24/2011 11:18 AM, Greg Smith wrote:
> sync=14525.296 s, total=14786.868 s
Whaaaaaaaaat!? 6% of 8GB is just shy of 500MB. That's not a small
amount, exactly, but it took 14525 seconds to call syncs for those
writes? What kind of ridiculous IO would cause something like that?
That's even way beyond an OS-level dirty buffer flush on a massive
system. Wow!
--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@peak6.com
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To: pgsql-performance@postgresql.org
Cc: sthomas@peak6.com, greg@2ndQuadrant.com
Subject: Re: Cost of creating an emply WAL segment
In-Reply-To: <4E04DDB3.8050306@peak6.com>
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