From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Colin McCabe" Subject: Re: unreadable drives can be synchronized? Date: Fri, 18 May 2007 14:18:16 -0400 Message-ID: <7296208f0705181118n32537ddck4d94bed08625b79f@mail.gmail.com> References: <200705181447.l4IElO2a000640@cichlid.com> <464DC06F.2080609@wpkg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <464DC06F.2080609@wpkg.org> Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: Tomasz Chmielewski Cc: Andrew Burgess , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 5/18/07, Tomasz Chmielewski wrote: > Andrew Burgess schrieb: > >> Basically, B appears to be "write-only"; it will never return an error on a > >> write, but just try to read from it, and you will be sorry. > > > > It would be interesting to see what SMART says about drive B, especially > > the short and long self tests. > > I wouldn't rely on SMART. > > I have a broken drive, which has lots of badblocks - but SMART happily > claims it's fine (short/long tests are completed without errors). > If you haven't seen Google's hard drive study yet, you should take a look. It's at http://labs.google.com/papers/disk_failures.pdf The conclusion says that "some of the SMART parameters are well-correlated with higher failure probabilities," but also that "a large fraction of [google's] failed drives have shown no SMART error signals whatsoever." Colin