On Thu, Jun 28, 2007 at 04:27:15AM -0400, Justin Piszcz wrote: > > > On Thu, 28 Jun 2007, Peter Rabbitson wrote: > > >Justin Piszcz wrote: > >>mdadm --create \ > >> --verbose /dev/md3 \ > >> --level=5 \ > >> --raid-devices=10 \ > >> --chunk=1024 \ > >> --force \ > >> --run > >> /dev/sd[cdefghijkl]1 > >> > >>Justin. > > > >Interesting, I came up with the same results (1M chunk being superior) > >with a completely different raid set with XFS on top: > > > >mdadm --create \ > > --level=10 \ > > --chunk=1024 \ > > --raid-devices=4 \ > > --layout=f3 \ > > ... > > > >Could it be attributed to XFS itself? More likely it's related to the I/O size being sent to the disks. The larger the chunk size, the larger the I/o hitting each disk. I think the maximum I/O size is 512k ATM on x86(_64), so a chunk of 1MB will guarantee that there are maximally sized I/Os being sent to the disk.... 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
