On Mon, Jul 16, 2007 at 10:50:34AM -0500, Eric Sandeen wrote:
> David Chinner wrote:
> > On Mon, Jul 16, 2007 at 12:41:15PM +1000, David Chinner wrote:
> >> On Fri, Jul 13, 2007 at 03:36:46PM -0400, Justin Piszcz wrote:
> ...
> >> If you've got any sort of serious disk array, ext3 is not the filesystem
> >> to use....
> >
> > To show what the difference is, I used blktrace and Chris Mason's
> > seekwatcher script on a simple, single threaded dd command on
> > a 12 disk dm RAID0 stripe:
> >
> > # dd if=/dev/zero of=/mnt/scratch/fred bs=1024k count=10k; sync
> >
> > http://oss.sgi.com/~dgc/writes/ext3_write.png
> > http://oss.sgi.com/~dgc/writes/xfs_write.png
>
> Were those all with default mkfs & mount options? ext3 in writeback
> mode might be an interesting comparison too.
Defaults. i.e.
# mkfs.ext3 /dev/mapper/dm0
# mkfs.xfs /dev/mapper/dm0
The mkfs.xfs picked up sunit/swidth correctly from the dm volume.
Last time I checked, writeback made little difference to ext3 throughput;
maybe 5-10% at most. I'll run it again later today...
Cheers,
Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
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