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From: Lowell Gilbert <freebsd-questions-local@be-well.ilk.org>
To: "Valeri Galtsev" <galtsev@kicp.uchicago.edu>
Cc: "Kevin P. Neal" <kpn@neutralgood.org>,
 Shamim Shahriar <shamim.shahriar@gmail.com>, freebsd-questions@freebsd.org
Subject: Re: Raid 1+0
References: <571533F4.8040406@bananmonarki.se> <57153E6B.6090200@gmail.com>
 <20160418210257.GB86917@neutralgood.org>
 <64031.128.135.52.6.1461017122.squirrel@cosmo.uchicago.edu>
Date: Tue, 19 Apr 2016 12:16:44 -0400
In-Reply-To: <64031.128.135.52.6.1461017122.squirrel@cosmo.uchicago.edu>
 (Valeri Galtsev's message of "Mon, 18 Apr 2016 17:05:22 -0500 (CDT)")
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"Valeri Galtsev" <galtsev@kicp.uchicago.edu> writes:

> Somebody with better knowledge of probability theory will correct me if
> I'm wrong some place.

Well, you are assuming that the probabilities of two drives failing 
are entirely independent of each other. The person to whom you are
responding asserted that this is not the case. Neither of you
presented any evidence directly to that point.