From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Keisler Subject: Re: RAID10 failure(s) Date: Mon, 14 Feb 2011 17:08:45 -0600 Message-ID: References: <20110215094802.44d99c58@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20110215094802.44d99c58@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Mon, Feb 14, 2011 at 4:48 PM, NeilBrown wrote: > On Mon, 14 Feb 2011 14:33:03 -0600 Mark Keisler w= rote: > >> Sorry for the double-post on the original. >> I realize that I also left out the fact that I rebooted since drive = 0 >> also reported a fault and mdadm won't start the array at all. =A0I'm= not >> sure how to tell which members were the in two RAID0 groups. =A0I wo= uld >> think that if I have a RAID0 pair left from the RAID10, I should be >> able to recover somehow. =A0Not sure if that was drive 0 and 2, 1 an= d 3 >> or 0 and 1, 2 and 3. >> >> Anyway, the drives do still show the correct array UUID when queried >> with mdadm -E, but they disagree about the state of the array: >> # mdadm -E /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 | grep 'Array Sta= te' >> =A0 =A0Array State : AAAA ('A' =3D=3D active, '.' =3D=3D missing) >> =A0 =A0Array State : .AAA ('A' =3D=3D active, '.' =3D=3D missing) >> =A0 =A0Array State : ..AA ('A' =3D=3D active, '.' =3D=3D missing) >> =A0 =A0Array State : ..AA ('A' =3D=3D active, '.' =3D=3D missing) >> >> sdc still shows a recovery offset, too: >> >> /dev/sdb1: >> =A0 =A0 Data Offset : 2048 sectors >> =A0 =A0Super Offset : 8 sectors >> /dev/sdc1: >> =A0 =A0 Data Offset : 2048 sectors >> =A0 =A0Super Offset : 8 sectors >> Recovery Offset : 2 sectors >> /dev/sdd1: >> =A0 =A0 Data Offset : 2048 sectors >> =A0 =A0Super Offset : 8 sectors >> /dev/sde1: >> =A0 =A0 Data Offset : 2048 sectors >> =A0 =A0Super Offset : 8 sectors >> >> I did some searching on the "READ FPDMA QUEUED" error message that m= y >> drive was reporting and have found that there seems to be a >> correlation between that and having AHCI (NCQ in particular) enabled= =2E >> I've now set my BIOS back to Native IDE (which was the default anywa= y) >> instead of AHCI for the SATA setting. =A0I'm hoping that was the iss= ue. >> >> Still wondering if there is some magic to be done to get at my data = again :) > > No need for magic here .. but you better stand back, as > =A0I'm going to try ... Science. > (or is that Engineering...) > > =A0mdadm -S /dev/md0 > =A0mdadm -C /dev/md0 -l10 -n4 -c256 missing /dev/sdc1 /dev/sdd1 /dev/= sde1 > =A0mdadm --wait /dev/md0 > =A0mdadm /dev/md0 --add /dev/sdb1 > > (but be really sure that the devices really are working before you tr= y this). > > BTW, for a near=3D2, Raid-disks=3D4 arrangement, the first and second= devices > contain the same data, and the third and fourth devices also containe= r the > same data as each other (but obviously different to the first and sec= ond). > > NeilBrown > > Ah, that's the kind of info that I was looking for. So, the third and fourth disks are a complete RAID0 set and the entire RAID10 should be able to rebuild from them if I replace the first two disks with new ones (hence being sure the devices are working)? Or I need to hope the originals will hold up to a rebuild? Thanks for the info, Neil, and all your work in FOSS :) -- 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