From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Wagoner Subject: Re: Raid 5 - not clean and then a failure. Date: Wed, 26 Aug 2009 10:14:31 -0400 Message-ID: <7d86ddb90908260714j4ddc6b56w580b511bdcf12491@mail.gmail.com> References: <15771.7292.qm@web51312.mail.re2.yahoo.com> <87hbvu9626.fsf@frosties.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <87hbvu9626.fsf@frosties.localdomain> Sender: linux-raid-owner@vger.kernel.org To: Goswin von Brederlow Cc: Jon@ehardcastle.com, linux-raid@vger.kernel.org List-Id: linux-raid.ids Wouldn't weekly RAID consistency checks reveal a bad block before you had a failure that required the need to do a full resync? It only takes 3 hours to resync my 3 x 1TB drives and having a bitmap would reduce the performance. I've never had to have a resync in the year I've had the array up. I just wonder if the performance drawback is worth having the bitmap to save a possible resync once every couple years. Or are the RAID consistency checks not reliable enough to prevent more errors during a resync? Ryan On Wed, Aug 26, 2009 at 7:18 AM, Goswin von Brederlow wrote: > Jon Hardcastle writes: > >> 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 dri= ves 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 wa= s in an inconsistent state (not sure of the *exact* error message). I t= hen 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 t= he array failed. >> >> Is there any hope for my data? If i get a good controller in there w= ill the resync continue? can I try and tell it to assume the drives are= good (which they ought to be)? >> >> Please help! > > 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 drive= s > 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. > > 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. > > MfG > =A0 =A0 =A0 =A0Goswin > -- > 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 =A0http://vger.kernel.org/majordomo-info.html > -- 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