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From: David Magda <dmagda@ee.ryerson.ca>
Date: Sat, 14 May 2005 11:33:38 -0400
To: Pawel Jakub Dawidek <pjd@freebsd.org>
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On May 14, 2005, at 09:16, Pawel Jakub Dawidek wrote:

> This is the way RAID1 works. Try to imagine how disk's heads are 
> moving -
> there will be no speed-up in sequential reads, this is not RAID0.
>
> Mirror characteristics are:
> - the same speed for sequential reads as for one disk;
> - the same speed for sequential/random write as for one disk;
> - double speed of one disk for random reads;

The following paper describes the I/O characteristics of various RAID 
schemes:

http://citeseer.ist.psu.edu/chen89evaluation.html

The following two may also be of some interest:

http://citeseer.ist.psu.edu/chen90maximizing.html
http://citeseer.ist.psu.edu/219910.html