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

From: Szabolcs Szakacsits
Date: Wed Aug 20 2008 - 22:46:27 EST



On Thu, 21 Aug 2008, Dave Chinner wrote:
> 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?

Everything is default.

% rpm -qf =mkfs.xfs
xfsprogs-2.9.8-7.1

which, according to ftp://oss.sgi.com/projects/xfs/cmd_tars, is the
latest stable mkfs.xfs. Its output is

meta-data=/dev/sda8 isize=256 agcount=4, agsize=1221440 blks
= sectsz=512 attr=2
data = bsize=4096 blocks=4885760, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=0
realtime =none extsz=4096 blocks=0, rtextents=0

Kernel xfs log:

SGI XFS with ACLs, security attributes, realtime, large block/inode numbers, no debug enabled
SGI XFS Quota Management subsystem
XFS mounting filesystem sda8
Ending clean XFS mount for filesystem: sda8

Szaka

--
NTFS-3G: http://ntfs-3g.org

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