From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goswin von Brederlow Subject: Re: Raid 5 - not clean and then a failure. Date: Wed, 26 Aug 2009 22:34:30 +0200 Message-ID: <873a7exqjt.fsf@frosties.localdomain> References: <73066.92033.qm@web51304.mail.re2.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <73066.92033.qm@web51304.mail.re2.yahoo.com> (Jon Hardcastle's message of "Wed, 26 Aug 2009 04:29:39 -0700 (PDT)") Sender: linux-raid-owner@vger.kernel.org To: Jon@eHardcastle.com Cc: Goswin von Brederlow , linux-raid@vger.kernel.org List-Id: linux-raid.ids Jon Hardcastle writes: > --- On Wed, 26/8/09, Goswin von Brederlow wrote: > >> From: Goswin von Brederlow >> Subject: Re: Raid 5 - not clean and then a failure. >> To: Jon@eHardcastle.com >> Cc: linux-raid@vger.kernel.org >> Date: Wednesday, 26 August, 2009, 12:18 PM >> Jon Hardcastle >> writes: >>=20 >> > Guys, >> > >> > I have been having some problems with my arrays that I >> think i have nailed down to a pci controller (well I say >> that - it is always the drives connected to *a* controller >> but I have tried 2!) anyway the latest saga is i was trying >> some new kernel options last night - which didn't work. >> > >> > But when i booted up again this morning it said one of >> the drives was in an inconsistent state (not sure of the >> *exact* error message). I then kicked off an add of the >> drive and it started syncing. It got about 5% in and then >> the second drive in on that controller complained and the >> array failed.=20 >> > >> > Is there any hope for my data? If i get a good >> controller in there will the resync continue? can I try and >> tell it to assume the drives are good (which they ought to >> be)? >> > >> > Please help! >>=20 >> The inconsistency is probably just a block here or there >> and I'm >> assuming none of your drives actualy failed. So 99.9999% of >> your data >> should be there. Just rebooting might actualy just get your >> raid back >> (to syncing). If not then you have to force reassembly from >> the drives >> with the newest serials. That will give you some data >> corruption, >> whatever was writing when the controler gave errors. Worst >> case you >> have to recreate the raid with --assume-clean. >>=20 >> I recommend adding a bitmap to the raid. That way a >> wrongfully failed >> drive can be resynced in a matter of minutes instead of >> hours or >> days. Makes it way less likely another error occurs during >> resync. >>=20 >> MfG >> =A0 =A0 =A0 =A0 Goswin >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-raid" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at=A0 http://vger.kernel.org/majordomo-info.html >>=20 > > I did look into bitmaps *abit* i could easily have the imagine for my= 6 drive raid 5 stored on the raid1 I have in the same system.. The goo= gling I did tho did not paint a pretty picture it talked about huge per= formance hits? That depends on the bitmap size a lot. It also depends on the frequency of errors. If your controler has a hickup once a week causing a drive to fail and you need 1 day to rebuild the array you will be left with a double disk failure pretty quickly without bitmaps. MfG Goswin -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html