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 - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
