On Fri, Dec 01, 2006 at 11:59:08PM +0000, Christian Kujau wrote:
> On Fri, 1 Dec 2006, Iustin Pop wrote:
> >I don't understand how you took that conclusion. The explanations refer
> >to the default log size. I believe the original poster asked about the
> >performance advantage of *raising* the log size above the default values
> >for internal logs,
>
> I was under the assumption that the OP asked about altering the size of
> the log at all and the manpage only states a reason for *decreasing* the
> logsize.
Ah, I see. Sorry for the confusion.
> >and my impression is that metadata-intensive
> >workloads benefit from increasing the log size (however no hard numbers
> >are available).
>
> As no numbers are known to me either, I did not see a point in
> increasing the log, hence my statement.
Hmm, I am pretty sure that it makes a difference, but only from personal
experience, not from benchmarks. A while ago, mkfs.xfs used to make <8M
logs even for big filesystems[0]. Nowadays it chooses a more sane value.
> >A while back when mkfs.xfs had more conservative default value, bigger log
> >sizes indeed helped for big filesystems.
>
> As I've done a few benchmarks[0] for different filesystems lately I
> might find some time to play around with different fs tweaks...
That would be interesting!
[0] http://oss.sgi.com/archives/xfs/2002-04/msg00443.html and the
corresponding thread, especially
http://oss.sgi.com/archives/xfs/2002-04/msg00441.html
Iustin
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