FreeBSD 5.3 I/O Performance / Linux 2.6.10 | Continued Discussion

Nick Pavlica linicks at
Tue Feb 1 15:50:07 PST 2005

  I was wondering if any progress has been made in determining the
cause of the poor disk I/O performance illustrated by the testing in
this thread?  Now that 5.3 is labeled as the production stable
version, and 4.x is labeled as legacy,  improving the performance of
the 5.4+ distributions is clearly important.  I know that everyone is
working hard to do this, and wanted to help by testing(retest, etc)
the disk I/O performance on 5.4 devel/final and post the results as
soon as possible.  I would also like others to join me in this testing
effort so that we have as much feedback as possible.  My hope is that
we will start bridging the large disk I/O performance gap demonstrated
in the 4.11 & 5.3 testing.

-  When would be best time to start this testing?
-  What is the preferred method for keeping in sync with the current
devel branch?  I'm assuming cvs-up is the best method.

--Nick Pavlica


On Fri, 28 Jan 2005 09:52:38 +0000 (GMT), Robert Watson
<rwatson at> wrote:
> On Thu, 27 Jan 2005, Mike Tancsa wrote:
> > >I/O (reads, writes at fairly large multiples of the sector size -- 512k is
> > >a good number) and small I/O size (512 bytes is good).  This will help
> > >identify the source along two dimmensions: are we looking at a basic
> > >storage I/O problem that's present even without the file system, or can we
> > >conclude that some of the additional extra cost is in the file system code
> > >or the hand off to it.  Also, with the large and small I/O size, we can
> > >perhaps draw some conclusions about to what extent the source is a
> > >per-transaction overhead.
> >
> > Apart from postmark and iozone (directly to disk and over nfs), are
> > there any particular tests you would like to see done ?
> Just to get started, using dd to read and write at various block sizes is
> probably a decent start.  Take a few samples, make sure there's a decent
> sample size, etc, and don't count the first couple of runs.
> Robert N M Watson
> _______________________________________________
> freebsd-questions at mailing list
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at"

More information about the freebsd-performance mailing list