From: Steve Poe <steve.poe@gmail.com>
To: Luke Lonergan <llonergan@greenplum.com>
Cc: Alex Turner <armtuk@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Postgresql Performance on an HP DL385 and
Date: Tue, 8 Aug 2006 09:57:43 -0700
Message-ID: <721b21dc0608080957k166a7bc5t72cb3cf076e6da01@mail.gmail.com> (raw)
In-Reply-To: <C0FE0847.2D986%llonergan@greenplum.com>
References: <721b21dc0608080801l5fb6534ey7094774ff79a323b@mail.gmail.com>
<C0FE0847.2D986%llonergan@greenplum.com>
Luke,
Here's some background:
I use Pg 7.4.13 (I've tested as far back as 7.4.8). I use an 8GB data with a
program called odbc-bench. I run an 18 minute test. With each run, HP box
excluded, I unmount the discs involved, reformat, un-tar the backup of
PGDATA and pg_xlog back on the discs, start-up Postgresql, then run the
odbc-bench.
On the Sun box, I've benchmarked an average of 3 to 4 runs with each disc
(up to 8) in succession in RAID0, RAID5, and RAID10 where applicable. I've
done with with pg_xlog on the same discs as PGDATA and separately, so I've
felt like I had a good understanding of how the performance works. I've
notice performance seems to level off at around 6 discs with another 10-15%
with two more discs.
When I run odbc-bench, I also run vmstat in the background (through a python
script) which averages/summarzies the high/low/average of each category for
each minute then a final summary after the run.
On the Sun box, with 4 discs (RAID10) to one channel on the LSI RAID card, I
see an average TPS around 70. If I ran this off of one disc, I see an
average TPS of 32.
on the HP box, with 6-discs in RAID10 and 1 spare. I see a TPS of 34. I
don't have my vmstat reports with me, but I recall the CPU utilitization on
the HP was about 50% higher. I need to check on this.
Steve
On 8/8/06, Luke Lonergan <llonergan@greenplum.com> wrote:
>
> Steve,
>
> On 8/8/06 8:01 AM, "Steve Poe" <steve.poe@gmail.com> wrote:
>
> > Thanks for the feedback. I use the same database test that I've run a
> Sun
> > dual Opteron with 4Gb RAM and (2) four disk arrays in RAID10. The sun
> box with
> > one disc on an LSI MegaRAID 2-channel adapter outperforms this HP box. I
> > though I was doing something wrong or there is something wrong with the
> box.
>
> Given the circumstances (benchmarked I/O is great, comparable perf on
> another box with single disk is better), seems that one of:
> 1) something wrong with the CPU/memory on the box
> 2) something with the OS version / kernel
> 3) something with the postgres configuration
>
> Can you post the database benchmark results?
>
> - Luke
>
>
>
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To: pgsql-performance@postgresql.org
Cc: steve.poe@gmail.com, llonergan@greenplum.com, armtuk@gmail.com
Subject: Re: Postgresql Performance on an HP DL385 and
In-Reply-To: <721b21dc0608080957k166a7bc5t72cb3cf076e6da01@mail.gmail.com>
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