From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Janos Haar" Subject: Re: Suggestion needed for fixing RAID6 Date: Thu, 22 Apr 2010 22:48:37 +0200 Message-ID: <66ba01cae25d$2fcd73b0$0400a8c0@dcccs> References: <626601cae203$dae35030$0400a8c0@dcccs> <4BD0AF2D.90207@stud.tu-ilmenau.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed reply-type=original Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: linux-raid-owner@vger.kernel.org To: st0ff@npl.de Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi, ----- Original Message -----=20 =46rom: "Stefan /*St0fF*/ H=FCbner" To: "Janos Haar" Sent: Thursday, April 22, 2010 10:18 PM Subject: Re: Suggestion needed for fixing RAID6 > Hi Janos, > > I'd ddrescue the failing drives one by one to replacement drives. Se= t a > very high retry-count for this action. I know what am i doing, trust me. ;-) I have much more professional tools for this than the ddrescue, and i h= ave the list of defective sectors as well. Now i am imaging the second of the failing drives, and this one have >1= 800 failing sectors. > > The logfile ddrescue creates shows the unreadable sectors afterwards. > The hard part would now be to incorporate the raid-algorithm into som= e > tool to just restore the missing sectors... I can do that, but it is not a good game for 15TB array or even some hu= ndred of sectors to fix by hand.... The linux md knows how to recalculate these errors, i want to find this way....somehow... I am thinking of making RAID1 from the defective drives, and if the ker= nel will re-write the sectors, the copy will get it. But i don't know how to prevent the copy to read it. :-/ Thanks for your suggestions, Janos > > I hope this helps a bit. > Stefan > > Am 22.04.2010 12:09, schrieb Janos Haar: >> Hello Neil, list, >> >> I am trying to fix one RAID6 array wich have 12x1.5TB (samsung) driv= es. >> Actually the array have 1 missing drive, and 3 wich have some bad >> sectors! >> Genearlly because it is RAID6 there is no data lost, because the bad >> sectors are not in one address line, but i can't rebuild the missing >> drive, because the kernel drops out the bad sector-drives one by one >> during the rebuild process. >> >> My question is, there is any way, to force the array to keep the mem= bers >> in even if have some reading errors? >> Or is there a way to re-add the bad sector drives after the kernel >> dropped out without stopping the rebuild process? >> In normal way after 18 hour sync, @ 97.9% the 3rd drive is always >> dropped out and the rebuild stops. >> >> Thanks, >> Janos Haar >> --=20 >> 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 http://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