From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: 3-way mirrors Date: Wed, 08 Sep 2010 18:28:19 -0400 Message-ID: <4C880E03.3080109@tmr.com> References: <20100907190255.15094.qmail@science.horizon.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100907190255.15094.qmail@science.horizon.com> Sender: linux-raid-owner@vger.kernel.org To: George Spelvin Cc: Simetrical+list@gmail.com, linux-raid@vger.kernel.org List-Id: linux-raid.ids George Spelvin wrote: >> This might be useful reading: >> >> http://neil.brown.name/blog/20100211050355 >> > > An interesting point of view, BUT... > > If I am seeing repeated unexplained mismatches (despite being on a good > UPS and having no unclean shutdowns), then some part of my hardware is > failing, and I'd like to know *what part*. > How about your disk enclosure? I would think that if vibration caused a silent bit flip *on write* you would get a read error (CRC) reading it back. but... I am going on the theory that any factor which causes measurable errors on read is not doing anything good for writes either. See: http://www.zdnet.com/blog/storage/bad-bad-bad-vibrations/896 -- Bill Davidsen "We can't solve today's problems by using the same thinking we used in creating them." - Einstein