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Subject: Re: [Qemu-devel] Re: [RFC] Disk integrity in QEMU
From: Laurent Vivier <Laurent.Vivier@bull.net>
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Date: Thu, 16 Oct 2008 12:24:40 +0200
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To: qemu-devel@nongnu.org
Cc: Chris Wright <chrisw@redhat.com>, Mark McLoughlin <markmc@redhat.com>, Ryan Harper <ryanh@us.ibm.com>

Hi,

I've made a benchmark using a database:
mysql and sysbench in OLTP mode.

cache=3Doff seems to be the best choice in this case...

mysql database
http://sysbench.sourceforge.net

sysbench --test=3Doltp

200,000 requests on 2,000,000 rows table.

                 | total time | per-request stat (ms) |
                 |  (seconds) |  min  |  avg  |  max  |
-----------------+------------+-------+-------+-------+
baremetal        |   208.6237 |   2.5 |  16.7 | 942.6 |
-----------------+------------+-------+-------+-------+
cache=3Don         |   642.2962 |   2.5 |  51.4 | 326.9 |
-----------------+------------+-------+-------+-------+
cache=3Don,O_DSYNC |   646.6570 |   2.7 |  51.7 | 347.0 |
-----------------+------------+-------+-------+-------+
cache=3Doff        |   635.4424 |   2.9 |  50.8 | 399.5 |
-----------------+------------+-------+-------+-------+

Laurent
--=20
------------------ Laurent.Vivier@bull.net  ------------------
"Tout ce qui est impossible reste =C3=A0 accomplir"    Jules Verne
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