--- On Fri, 10/16/09, Rob Becker <Rob.Becker@riverbed.com> wrote:

   What command did you use to create your
raid-10?

/
mdadm --create /dev/md0 --level=raid1 --chunk=256 --raid-disks=2 missing /dev/sdb1
swap
mdadm --create /dev/md1 --level=raid10 --layout=o2 --chunk=256 --raid-disks=2 missing /dev/sdb2
/home
mdadm --create /dev/md2 --level=raid10 --layout=o2 --chunk=1024 --raid-disks=2 missing /dev/sdb3
... then copied files and later added the sda parts to the array. (RAID conversion on live system)

 You might try  
running iostat in parallel to see if the read_balancer is
properly  
balancing the reads between the two disks.

Don't understand this as I'm a bit of a n00b...

--- On Fri, 10/16/09, Tomasz Chmielewski <mangoo@wpkg.org> wrote:

If you only use your RAID-10 array for a single "dd
if=bigfile of=/dev/null" then yes, it does not give you much
over mirroring.

If you start using your drives for two "dd if=bigfile[12]
of=/dev/null" at the same time, you will notice the
difference.

OK so it was a fallacy to think this would help with large files, unless more than one is involved.