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Date: Wed, 6 May 2009 08:20:25 +0200 (CEST)
From: Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl>
To: Yuri <yuri@rawbw.com>
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Cc: freebsd-questions@freebsd.org
Subject: Re: What is the highest hard drive read/write speed you were able
 to achieve by entire disk mirroring or striping?
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> I am seeing 85MB/s as a speed of a single Hitachi 1TB HD.
> How high can you go by mirroring or striping 2, 3, 4 harddrives?

mirroring - the same, just with 2 processes reading both can get the 
bandwidth. make sure you use -s high enough (like 1048576) doing gmirror 
label

stripping - the same, or 2,3,4 times, depends how you configure.
for highest transfer and lowest concurrency (you mostly read huge files 
with one process) - use small stripe size.
for lowest transfer (=1 disk) and highest concurency - use very huge 
stripe size like 512MB, so simply different process reading different 
things can hit different drives, but each I/O isn't spread.