From: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
To: Grzegorz Jaśkiewicz <gryzman@gmail.com>
Cc: postgres performance list <pgsql-performance@postgresql.org>
Subject: Re: serveRAID M5014 SAS
Date: Fri, 27 May 2011 10:43:25 +1200
Message-ID: <4DDED78D.6060508@catalyst.net.nz> (raw)
In-Reply-To: <BANLkTin_R98uAP4gCutGB61uTNoQSgELbA@mail.gmail.com>
References: <BANLkTi=fE2YCS0Lra42ei1hFrKqXdVk2jA@mail.gmail.com>
<4DDD81BB.4080801@catalyst.net.nz>
<4DDD85C7.6030109@catalyst.net.nz>
<BANLkTi=PAymQvudx1eyuuOV9vAAoydan9g@mail.gmail.com>
<4DDE0E77.6070804@catalyst.net.nz>
<BANLkTin_R98uAP4gCutGB61uTNoQSgELbA@mail.gmail.com>
On 26/05/11 20:31, Grzegorz Jaśkiewicz wrote:
> Would HT have any impact to the I/O performance (postgresql, and fs in
> general) ?.
>
There have been previous discussions on this list about HT on vs off (I
can't recall what the consensus, if any about what the cause of any
performance difference was). In our case HT off gave us much better
results for what we think the typical number of clients will be - see
attached (server learn-db1 is setup with trivial hardware raid and then
software raided via md, learn-db2 has its raid all in hardware. We've
ended up going with the latter setup).
Note that the highest tps on the graph is about 2100 - we got this upto
just over 2300 by changing from ext4 to xfs in later tests, and managed
to push the tps for 100 clients up a little by setting no read ahead
(NORA) for the arrays.
Cheers
Mark
Attachments:runhtoff.png (image/png, 14.5K) downloadview imagerunhton.png (image/png, 14.0K) downloadview image
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: mark.kirkwood@catalyst.net.nz, gryzman@gmail.com
Subject: Re: serveRAID M5014 SAS
In-Reply-To: <4DDED78D.6060508@catalyst.net.nz>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox