ZFS performance question

[Heinrich Rebehn]

Hi all,

After setting up our new server (Intel Q9550 CPU, 8GB RAM, 4 x ST31000340NS) i did a bonnie++ benchmark on the zfs raidz that i created on 4 partitions on the 4 disks.

root at antsrv4 [/data/nocompression] # bonnie++ -u root -d .
Using uid:0, gid:0.
Writing a byte at a time...done
Writing intelligently...done
Rewriting...done
Reading a byte at a time...done
Reading intelligently...done
start 'em...done...done...done...done...done...
Create files in sequential order...done.
Stat files in sequential order...done.
Delete files in sequential order...done.
Create files in random order...done.
Stat files in random order...done.
Delete files in random order...done.
Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
antsrv4.ant.uni 16G    94  81 151823  39 100780  27   303  99 239853  30 148.3   4
Latency              4733ms    6051ms    8173ms   37504us     917ms    1030ms
Version  1.96       ------Sequential Create------ --------Random Create--------
antsrv4.ant.uni-bre -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16 24183  97 +++++ +++ 21715  98 17209  98 +++++ +++ 21291  97
Latency             19779us     128us     162us   39671us      38us      77us
1.96,1.96,antsrv4.ant.uni-bremen.de,1,1282303232,16G,,94,81,151823,39,100780,27,303,99,239853,30,148.3,4,16,,,,,24183,97,+++++,+++,21715,98,17209,98,+++++,+++,21291,97, 733ms,6051ms,8173ms,37504us,917ms,1030ms,19779us,128us,162us,39671us,38us,77us


I am somewhat concerned about the numbers for per-char-output and per-char-input. In fact, i have never before seen that low numbers in a bonnie test. Using a single disk with UFS yields about 6 times as much.


I know that this is not crucial for a normal file server, but i want to rule out any configuration errors.

Is this normal for ZFS?. Disks are accessed using ahci. I did not attempt any tuning yet.

BTW: Running OpenSolaris on the same hardware yields 110306 for per-char-write and 94698 for per-char-read.

--Heinrich


Heinrich Rebehn

University of Bremen
Physics / Electrical and Electronics Engineering
- Department of Telecommunications -

Phone : +49/421/218-62394
Fax   :            -3341