From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Colls Subject: Re: Raid Problem - Unknown File System Type Date: Wed, 09 Nov 2011 12:12:28 -0500 Message-ID: <4EBAB47C.5070002@rogers.com> References: <4EBAA68B.6090906@rogers.com> <20111109163933.GA26630@cthulhu.home.robinhill.me.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20111109163933.GA26630@cthulhu.home.robinhill.me.uk> Sender: linux-raid-owner@vger.kernel.org To: "linux-raid@vger.kernel.org" List-Id: linux-raid.ids On 11/09/2011 11:39 AM, Robin Hill wrote: > On Wed Nov 09, 2011 at 11:12:59AM -0500, William Colls wrote: > >> >> Environment >> >> Kubuntu Linux 10.04.3 LTS >> mdadm 2.6.7.1-1ubuntu15 >> >> I have two identical disks that were in a raid configuration in another >> machine (also running 10.04). I removed them from the old machine, >> mounted them in a new machine, booted up, and at a terminal prompt as >> root issued >> >> mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb /dev/sdc >> > You should have just assembled them. You've now created a new array > instead of just assembling the old one. I thought, at the time, that I needed to do the create so that the /dev/md0 device would be created properly (new machine had no raid before). > >> The configuration in the old machine was raid 1. >> >> I checked the contents of /proc/mdstat and it confirmed that md0 was >> indeed running, with 2 devices, as expected. But it also said it was >> resyncing the disks, which I didn't expect. >> >> When the reync completed, I was unable to mount /dev/md0p1. Specifying >> -t ext3 in the mount command gives the error message "wrong fs, bad >> option, bad superblock on /dev/md0p1". Trying mount with no -t gives the >> error "unknown file type linux_raid_member". Looking at the disks with >> Gparted, confims that the system sees the disks, but the filesystem >> shows as unknown. >> > It would look like the old array was either created with an older mdadm > version (with different defaults) or used some non-default parameter > values. > >> The output from mdamd --detail /dev/sdb >> >> /dev/sdb: >> Magic : a92b4efc >> Version : 00.90.00 >> UUID : 1443e74d:f63f16ab:d527ef8c:7225e0b0 >> Creation Time : Tue Nov 8 13:14:48 2011 >> Raid Level : raid1 >> Used Dev Size : 732574464 (698.64 GiB 750.16 GB) >> Array Size : 732574464 (698.64 GiB 750.16 GB) >> Raid Devices : 2 >> Total Devices : 2 >> Preferred Minor : 0 >> >> Update Time : Tue Nov 8 16:05:42 2011 >> State : clean >> Active Devices : 2 >> Working Devices : 2 >> Failed Devices : 0 >> Spare Devices : 0 >> Checksum : c4195c85 - correct >> Events : 34 >> >> >> Number Major Minor RaidDevice State >> this 0 8 16 0 active sync /dev/sdb >> >> 0 0 8 16 0 active sync /dev/sdb >> 1 1 8 32 1 active sync /dev/sdc >> >> --- end of output >> >> Output from mdadm --examine /dev/sdc >> >> /dev/sdc: >> Magic : a92b4efc >> Version : 00.90.00 >> UUID : 1443e74d:f63f16ab:d527ef8c:7225e0b0 >> Creation Time : Tue Nov 8 13:14:48 2011 >> Raid Level : raid1 >> Used Dev Size : 732574464 (698.64 GiB 750.16 GB) >> Array Size : 732574464 (698.64 GiB 750.16 GB) >> Raid Devices : 2 >> Total Devices : 2 >> Preferred Minor : 0 >> >> Update Time : Tue Nov 8 16:05:42 2011 >> State : clean >> Active Devices : 2 >> Working Devices : 2 >> Failed Devices : 0 >> Spare Devices : 0 >> Checksum : c4195c97 - correct >> Events : 34 >> >> >> Number Major Minor RaidDevice State >> this 1 8 32 1 active sync /dev/sdc >> >> 0 0 8 16 0 active sync /dev/sdb >> 1 1 8 32 1 active sync /dev/sdc >> >> ---- end of output >> >> So - am I truly up the creek without a paddle? Is there any way to >> recover this array? I have backups of most of it, but it will take a >> while to find and restore. And for sure something will be lost. >> > > Certainly most of the data should be there still. I don't suppose you > have a copy of the mdadm --examine output from the old system at all? No output from the original setup. > > Cheers, > Robin -- I know you believe that you understand what you think I said, but I am not sure that you realize that what you heard was not what I ment.