[Bioclusters] Tool to benchmark disk IO?

Joe Landman bioclusters@bioinformatics.org
Sat, 25 Sep 2004 10:50:15 -0400

Hi Guy:

  With version 3 of NFS, you might try

Version 3 lets you do 32k rsize/wsize.  TCP can be (but isn't always) a 
win. You might experiment with the noatime, and some of the other 
switches.  There are some other "tricks" as well to tuning NFS.  It 
isn't too difficult to hit wire speed over 100 base T, it is a bit 
harder to hit it over gigabit.  Lots more to tune (including disk).  I 
would recommend XFS or JFS as the underlying exported file system.  Ext3 
still has some non-optimized serializing code paths in its journaling 
system that make it hard to get very good performance out of it.


Guy Coates wrote:

>One thing which makes a big difference in IO speed is tweaking the various
>mount options:
>For your NFS mounts, the following is a good start (maybe proto=tcp if
>your server supports it):
>For ext3, mount  with "data=writeback"[1], and for reiserfs mount  with
>"notail" options.  If you've got it compiled into your kernel, XFS is
>worth trying too. It is quite speedy.
>[1] Check the man page for what this does; if you machine goes down in the
>middle of a file write you stand an increase chance of that file getting
>mangled; the filesystem itself should be OK.
> --
>Dr. Guy Coates,  Informatics System Group
>The Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK
>Tel: +44 (0)1223 834244 ex 7199
>Bioclusters maillist  -  Bioclusters@bioinformatics.org

Joseph Landman, Ph.D
Scalable Informatics LLC,
email: landman@scalableinformatics.com
web  : http://www.scalableinformatics.com
phone: +1 734 612 4615