From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raphael Delaporte Subject: Re: Did --zero-superblock by mistake ... How can I get back data ? Date: Fri, 10 Mar 2006 21:23:52 +0100 Message-ID: <4411E058.7000601@free.fr> References: <4411BF56.7010801@free.fr> <4411D5AB.2030609@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4411D5AB.2030609@us.ibm.com> Sender: linux-raid-owner@vger.kernel.org To: Mike Tran Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Mike Tran a =E9crit : > Raphael Delaporte wrote: > >> Hi, >> >> On a RAID 5 array which is composed by 5 hdd, I did mdadm=20 >> --zero-superblocks on each hdd because I thought it was required to=20 >> use the array on a new system.... >> >> But now, I cannot mdadm --assemble the array. It says : >> >> mdadm: no RAID superblock on /dev/sda >> mdadm: /dev/sda has no superblock - assembly aborted >> >> Is it possible to assemble this array because I don't want to lose m= y=20 >> data... Someone told me that I can do a : >> >> mdadm -Cv /dev/md0 -l5 -n5 /dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/= hdc >> >> But if do that, all the data on the raid will be lost or not ? >> >> Is there an other way to get back these data ? >> >> Thank you very much for your help. >> > I would try to recreate the raid5 array with *1 missing disk,* then=20 > try to mount the array (read only) and verify the data. > > For example, > mdadm -C /dev/md0 -l 5 -c 32 -p ls -n 5 /dev/sda /dev/sdb /dev/sdc=20 > /dev/sdd missing > > Notes: > If you used /etc/mdadm.conf, specify the disk order on the ARRAY line= =20 > with 1 missing disk to be safe. > I specified the mdadm default chunk size (32K) and default parity=20 > algorithm (left-symmetric). You may have to use other values. > You should change the order of the disks if your data is invalid. > > --=20 > Regards, > Mike T. > > - > 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 > > Yeah, thank you, it worked perfectly ! Thank you for your help ! -- Raph - 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