From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goswin von Brederlow Subject: Re: Read errors on raid5 ignored, array still clean .. then disaster !! Date: Wed, 27 Jan 2010 16:06:26 +0100 Message-ID: <87wrz337v1.fsf@frosties.localdomain> References: <4B5F6C73.30707@texsoft.it> <4B6000F0.2000405@shiftmail.org> <4B6010F5.6030702@texsoft.it> <4B601A5F.9050301@shiftmail.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <4B601A5F.9050301@shiftmail.org> (asdo@shiftmail.org's message of "Wed, 27 Jan 2010 11:50:07 +0100") Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Asdo writes: > Giovanni Tessore wrote: >> I didn't setup smart monitoring... Luca is right. >> But I dont like the idea that md relies on another tool, that could >> be not installed or correctly configured, to warn the user on >> potential critical situations which involve directly itself. >> >> From the logs, it results that it did a "check" on md3 the 4 january >> (first read errors at beginning of december, failure of other disk >> 18 january); no read error occurred. >> Looks like it did not help much :( >> Maybe I was just very unluky > > It's strange... quite unlucky I'd say... > Maybe the check needs to be run more frequently, like weekly. > (Asdo taking notes... :-D) > I also am not expert of this kind of statistics. > FWIW I have seen two hardware raid controllers, and they do the scrub > weekly by default. I don't know if they also run SMART tests. > > Also is it possible that you experienced an electricity surge or a > physical shock on the computer? > > Obviously smart checks also help. > > Good luck > Asdo Or the check just does not report errors. You need to read your syslog/kernel log to see read errors and check the mismatch count after a check. Not all distributions do report mismatch count != 0 after a check. Most don't I think. MfG Goswin