Re: [PATCH RFC] nilfs2: continuous snapshotting file system

From: Dave Chinner
Date: Wed Aug 20 2008 - 22:13:21 EST


On Wed, Aug 20, 2008 at 02:39:16PM -0700, Andrew Morton wrote:
> On Thu, 21 Aug 2008 00:25:55 +0300 (MET DST)
> Szabolcs Szakacsits <szaka@xxxxxxxxxxx> wrote:
> > I ran compilebench on kernel 2.6.26 with freshly formatted volumes.
> > The behavior of NILFS2 was interesting.
> >
> > Its peformance rapidly degrades to the lowest ever measured level
> > (< 1 MB/s) but after a while it recovers and gives consistent numbers.
> > However it's still very far from the current unstable btrfs performance.
> > The results are reproducible.
> >
> > MB/s Runtime (s)
> > ----- -----------
> > btrfs unstable 17.09 572
> > ext3 13.24 877
> > btrfs 0.16 12.33 793
> > nilfs2 2nd+ runs 11.29 674
> > ntfs-3g 8.55 865
> > reiserfs 8.38 966
> > nilfs2 1st run 4.95 3800
> > xfs 1.88 3901
>
> err, what the heck happened to xfs? Is this usual?

No, definitely not usual. I suspect it's from an old mkfs and
barriers being used. What is the output of the xfs.mkfs when
you make the filesystem and what mount options being used?

Cheers,

Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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