Re: Disappointing RAID10 Performance

[adfas asd <chimera_god@yahoo.com>]

--- 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.