From: Gregory Stark <stark@enterprisedb.com>
To: Decibel! <decibel@decibel.org>
Cc: Jean-David Beyer <jeandavid8@verizon.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: random_page_costs - are defaults of 4.0 realistic for SCSI RAID 1
Date: Wed, 12 Sep 2007 00:02:46 +0100
Message-ID: <87r6l4ajqh.fsf@oxford.xeocode.com> (raw)
In-Reply-To: <20070911213105.GF38801@decibel.org>
References: <C30B1716.4236C%llonergan@greenplum.com>
<87lkbdlkxw.fsf@oxford.xeocode.com>
<46E676D6.70807@verizon.net>
<87zlzt9ifw.fsf@oxford.xeocode.com>
<46E6E338.5050403@verizon.net>
<20070911213105.GF38801@decibel.org>
"Decibel!" <decibel@decibel.org> writes:
> On Tue, Sep 11, 2007 at 02:49:28PM -0400, Jean-David Beyer wrote:
>> It is tricky for me to find a big enough file to test. I tried one of the
>
> dd if=/dev/zero of=bigfile bs=8192 count=1000000
On linux another useful trick is:
echo 1 > /proc/sys/vm/drop_caches
Also, it helps to run a "vmstat 1" in another window and watch the bi and bo
columns.
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
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To: pgsql-performance@postgresql.org
Cc: stark@enterprisedb.com, decibel@decibel.org, jeandavid8@verizon.net
Subject: Re: random_page_costs - are defaults of 4.0 realistic for SCSI RAID 1
In-Reply-To: <87r6l4ajqh.fsf@oxford.xeocode.com>
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