Re: raid10: unfair disk load?

[Bill Davidsen <davidsen@tmr.com>]

Richard Scobie wrote:
> Jon Nelson wrote:
>
>> My own tests on identical hardware (same mobo, disks, partitions,
>> everything) and same software, with the only difference being how
>> mdadm is invoked (the only changes here being level and possibly
>> layout) show that raid0 is about 15% faster on reads than the very
>> fast raid10, f2 layout. raid10,f2 is approx. 50% of the write speed of
>> raid0.

This more or less matches my testing.
>
> Have you tested a stacked RAID 10 made up of 2 drive RAID1 arrays, 
> striped together into a RAID0.

That is not raid10, that's raid1+0. See man md.
>
> I have found this configuration to offer very good performance, at the 
> cost of slightly more complexity.

It does, raid0 can be striped over many configurations, raid[156] being 
most common.

-- 
Bill Davidsen <davidsen@tmr.com>
  "Woe unto the statesman who makes war without a reason that will still
  be valid when the war is over..." Otto von Bismark