From: Jeffrey W. Baker <jwbaker@acm.org>
To: Ulrich Wisser <ulrich.wisser@relevanttraffic.se>
Cc: pgsql-performance@postgresql.org
Subject: Re: Need for speed
Date: Wed, 17 Aug 2005 09:49:37 -0700
Message-ID: <1124297377.423.2.camel@noodles> (raw)
In-Reply-To: <4303003B.3020407@relevanttraffic.se>
References: <Pine.LNX.4.44.0508162045480.2995-100000@zigo.dhs.org>
<4303003B.3020407@relevanttraffic.se>
On Wed, 2005-08-17 at 11:15 +0200, Ulrich Wisser wrote:
> Hello,
>
> thanks for all your suggestions.
>
> I can see that the Linux system is 90% waiting for disc io. At that time
> all my queries are *very* slow. My scsi raid controller and disc are
> already the fastest available.
What RAID controller? Initially you said you have only 2 disks, and
since you have your xlog on a separate spindle, I assume you have 1 disk
for the xlog and 1 for the data. Even so, if you have a RAID, I'm going
to further assume you are using RAID 1, since no sane person would use
RAID 0. In those cases you are getting the performance of a single
disk, which is never going to be very impressive. You need a RAID.
Please be more precise when describing your system to this list.
-jwb
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To: pgsql-performance@postgresql.org
Cc: jwbaker@acm.org, ulrich.wisser@relevanttraffic.se
Subject: Re: Need for speed
In-Reply-To: <1124297377.423.2.camel@noodles>
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