Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 8 Oct 2008 15:02:24 +0200
From:      Julien Drouard <jdrouard@ankama.com>
To:        "freebsd-questions@freebsd.org" <freebsd-questions@freebsd.org>
Subject:   Problem with writes on HD with FreeBSD 7
Message-ID:  <7AFA66599AC41847AD8E021A1DBB9D1403E32A56D2@pandore.ankama.com>

next in thread | raw e-mail | index | archive | help
Hi,

Since a few weeks some of our database servers are running under FreeBSD 7 =
and we have noticed that writes on HD take a lot of time. To confirm our im=
pression we ran sysbench. The results are the following :


*         Under FreeBSD 7 :

Random write :
Operations performed:  0 Read, 10000 Write, 12800 Other =3D 22800 Total
Read 0b  Written 156.25Mb  Total transferred 156.25Mb  (1.6459Mb/sec)
  105.34 Requests/sec executed

Test execution summary:
    total time:                          94.9312s
    total number of events:              10000
    total time taken by event execution: 41.1071
    per-request statistics:
         min:                            0.0000s
         avg:                            0.0041s
         max:                            0.1653s
         approx.  95 percentile:         0.0251s


*         Under FreeBSD 6.2 :

random write
Operations performed:  0 Read, 10005 Write, 12673 Other =3D 22678 Total
Read 0b  Written 156.33Mb  Total transferred 156.33Mb  (10.505Mb/sec)
  672.32 Requests/sec executed

Test execution summary:
    total time:                          14.8814s
    total number of events:              10005
    total time taken by event execution: 112.2531
    per-request statistics:
         min:                            0.0000s
         avg:                            0.0112s
         max:                            0.9868s
         approx.  95 percentile:         0.0010s

The command used for sysbench is : sysbench --num-threads=3D16 --test=3Dfil=
eio --file-total-size=3D3G --file-test-mode=3Drndwr run

I have found absolutely nothing to explain that differences so if someone c=
an help me to solve this problem I would be very grateful.

Kind Regards,

Julien



--=20
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?7AFA66599AC41847AD8E021A1DBB9D1403E32A56D2>