Re: detecting layout in RAID

[Neil Brown]

On Thursday December 12, [e-mail] wrote:
> hello,
> 	I am trying to detect layouts of the RAID configuration (I have a
> software RAID set up. ) Mine is currently left symmetric and the way I am
> trying to detect layout is to reaad consecutive blocks and look for
> whether there is a big dp when it has to move all the way across..

What exactly do you mean by "move all the way across"?
The only things that move are the drive which spins and the heads
which move back and forth.

I suspect that the way to detect differences in layout is to do lots
of random reads of different block sizes and look for different
throughput. 

NeilBrown