adfas asd wrote:
--- On Fri, 10/16/09, Rob Becker <Rob.Becker@xxxxxxxxxxxx> 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)
No wonder it's slow, you want two far copies, this is more or less
mirroring with only two drives. Using a large buffer size also helps,
you hurt your performance by limiting readahead. You can also use the
'blockdev' command (--setra) to increase your readahead on the array.
Just going to far should about double your speed, the other things may
help more.
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@xxxxxxxx> 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.
You are misconfigured.
--
Bill Davidsen <davidsen@xxxxxxx>
Unintended results are the well-earned reward for incompetence.
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