From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hardcastle Subject: Re: sdc1 does not have a valid v0.90 superblock, not importing! Date: Wed, 11 Aug 2010 04:19:07 -0700 (PDT) Message-ID: <314806.24793.qm@web51305.mail.re2.yahoo.com> References: <20100811210603.065284c8@notabene> Reply-To: Jon@eHardcastle.com Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20100811210603.065284c8@notabene> Sender: linux-raid-owner@vger.kernel.org To: Jon@eHardcastle.com, Neil Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --- On Wed, 11/8/10, Neil Brown wrote: > From: Neil Brown > Subject: Re: sdc1 does not have a valid v0.90 superblock, not import= ing! > To: Jon@eHardcastle.com > Cc: jd_hardcastle@yahoo.com, linux-raid@vger.kernel.org > Date: Wednesday, 11 August, 2010, 12:06 > On Wed, 11 Aug 2010 02:55:44 -0700 > (PDT) > Jon Hardcastle > wrote: >=20 > > (my first attempt appears to have been bounced as the > spam checker thought it had HTML in it?!) >=20 > odd... came through ok for me the first time. >=20 > >=20 > > Help! > >=20 > > Long story short - I was watching a movie off my RAID6 > array. Got a smart error warning >=20 > > Aug 10 22:00:07 mangalore kernel: raid5: cannot start > dirty degraded array for md4 >=20 > This is the current problem.=A0 The array is dirty and > degraded so there could > theoretically be undetectable corruption.=A0 Chance is > quite low but it is > there so md won't start with out you acknowledging the risk > by giving the > --force flag to mdadm --assemble. > Only do that if you are confident that your hardware is > working correctly. Well I am reasonable sure the controller came adrift the first time.. w= hen i reseated it i stopped getting 100's of errors.. and it has surviv= ed 1.5 badblocks checks. It is being held in place by one of those bars= you press down (does all the expansion cards in 1 go) except i dont th= ink it is very good. I will screw it down. >=20 > > It appears sdc has an invalid superblock? > >=20 > > This is the 'examine' from sdc1 (note the checksum) > >=20 > > /dev/sdc1: > ..... > >=A0 =A0 =A0=A0=A0Checksum : b335b4e3 - > expected b735b4e3 >=20 > Single bit error.=A0 That isn't good as it means some > bit of memory or some bit > on some bus somewhere cannot be trusted. > It could be a transient thing and will never happen > again.=A0 Or maybe not. > Given the smart errors and the fact that you have had > problems with the drive > before it seem very likely that the problem is in that > drive.=A0 I suggest > unplugging it and leaving it unplugged.=A0 Some memory > buffer in the drive is > probably marginal.=A0 I don't think they use ECC > memory. Could this be a result of me forcing a power off when the drive was cau= sing problems? What are the dangers to removing it, zeroing the superblock and readdin= g? is it MORE dangerous than leaving a raid 6 degraded for a few days? >=20 > >=20 > > Anyways... I am ASSUMING mdadm has not assembled the > array to be on the safe side? i have not done anything.. no > force... no assume clean.. I wanted to be sure? >=20 > You assume correctly. >=20 > >=20 > > Should i remove sdc1 from the array? It should then > assemble? I have 2 spare drives that I am getting around to > using to replace this drive and the other 500GB.. so should > I remove sdc1... and try and re-add or just put the new > drive in? > >=20 > > atm I have 'stop'ped the array and got badblocks > running.... > >=20 >=20 > Remove sdc and assemble the array with --force, and get a > new device to > replace /dev/sdc as soon as possible. Thanks Neil - I panic'd as previously it has mounted the array in a deg= raded state... but previously the drive has disappeared completely... w= hereas in this case it is present... but wrong! >=20 > NeilBrown > -- > 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 =20 -- 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