From mboxrd@z Thu Jan  1 00:00:00 1970
From: Asdo <asdo@shiftmail.org>
Subject: Re: Disappointing RAID10 Performance
Date: Sat, 17 Oct 2009 18:12:20 +0200
Message-ID: <4AD9ECE4.3090202@shiftmail.org>
References: <364346.70897.qm@web38808.mail.mud.yahoo.com>
 <4AD8BBC3.4030600@wpkg.org>
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To: Tomasz Chmielewski <mangoo@wpkg.org>
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Tomasz Chmielewski wrote:
> If you start using your drives for two "dd if=bigfile[12] 
> of=/dev/null" at the same time, you will notice the difference.

OT: Does this dd line really work? I did see it elsewhere already but 
doesn't appear to work for me: seems to see only the last if=. I don't 
think multiple input or output files are supported.
For this kind of tests I was doing a for loop with background dd comands 
( trailing & ) IIRC
This would be a good dd feature to simplify linux-raid performance 
testing though.