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Date: Mon, 27 Oct 2003 09:58:43 -0500
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To: Rishi Chopra <rchopra@cal.berkeley.edu>
From: Charles Swiger <cswiger@mac.com>
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Subject: Re: Choosing A Stripe-Size (RAID5 Array)
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On Sunday, October 26, 2003, at 07:42 PM, Rishi Chopra wrote:
> I'm setting up a 600GB Raid-5 array (4-200GB 8MB Buffer IDE disks 
> connected
> to an Adaptec 2400A controller) and would like some help picking a
> stripe-size (this is the smallest unit of data written to each disk by 
> the
> raid controller.)  My usage pattern is fileserver and webserver+db, 
> some
> light desktop usage as well.  I'll be using defaults for the file 
> system
> (16K block size.)

Databases really don't interact well with RAID-5; you would be better 
off using RAID-1 mirrors for the volumes which the DB uses.  RAID-5 is 
okay for fileserving if you're not write-intensive (ie, read-mostly)...

-- 
-Chuck