Mounting HDD with superblock problems

dstu · 07-12-2014, 02:58 AM

Hello,

I connected a HDD that was running on a server that stopped functioning to an Ubuntu server, but I don't succeed to mount it.

These are the results of fdisk and fsck commands:

Quote:

root@server:~# fdisk -l

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 15200 cylinders, total 244190646 sectors
Units = sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x000d2969

Device Boot Start End Blocks Id System
/dev/sdb1 63 1953520064 3519112712 83 Linux

Quote:

root@server:~# fsck /dev/sdb1
fsck from util-linux 2.20.1
e2fsck 1.42.9 (4-Feb-2014)
ext2fs_open2: Bad magic number in super-block
fsck.ext2: Superblock invalid, trying backup blocks...
fsck.ext2: Bad magic number in super-block while trying to open /dev/sdb1

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem. If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>
or
e2fsck -b 32768 <device>

I ran both e2fsck commands, but that didn't solve anything.

Can anyone help me? I have extremely important information on that disk.

Thanks in advance,

David

kilgoretrout · 07-12-2014, 05:16 PM

Post the output of:

# dumpe2fs /dev/sdb1 | grep -i superblock

That should printout the location of the backup superblocks. From there you can try the:

# e2fsck -b <backup superblock> /dev/sdb1

and see if you can get it to work.

dstu · 07-12-2014, 10:58 PM

Quote:

Originally Posted by kilgoretrout

Post the output of:

# dumpe2fs /dev/sdb1 | grep -i superblock

That should printout the location of the backup superblocks.

I ran that query, but it gave an error:

Quote:

root@server:~# dumpe2fs /dev/sdb1 | grep -i superblock
dumpe2fs 1.42.9 (4-Feb-2014)
dumpe2fs: Bad magic number in super-block while trying to open /dev/sdb1
Couldn't find valid filesystem superblock.

I also ran another command:

Quote:

root@server:~# mke2fs -n /dev/sdb1
mke2fs 1.42.9 (4-Feb-2014)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
61054976 inodes, 244190583 blocks
12209529 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
7453 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848

But from there, I tried all the backups listed, but got these 2 types of errors (Bad magic on the first half of the list and invalid argument on the 2nd):

Quote:

root@server:~# e2fsck -b 98304 /dev/sdb1
e2fsck 1.42.9 (4-Feb-2014)
e2fsck: Bad magic number in super-block while trying to open /dev/sdb1

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem. If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>
or
e2fsck -b 32768 <device>

root@server:~# e2fsck -b 214990848 /dev/sdb1
e2fsck 1.42.9 (4-Feb-2014)
e2fsck: Invalid argument while trying to open /dev/sdb1

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem. If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>
or
e2fsck -b 32768 <device>

kilgoretrout · 07-13-2014, 08:03 AM

Was this drive part of a raid array?

There's also a data recovery tool called TestDisk you might want to look into:

http://en.wikipedia.org/wiki/TestDisk

I believe it's in the standard ubuntu repositories. Haven't used it myself but it might be worth a try.

You should also eliminate the possibility that this is a hardware problem. Go to the hard drive manufacturer's website and download their hard drive diagnostic utilities. Seagate, Western Digital and some of the other major hard drive manufacturers provide them for free. You want to get the bootable iso version, burn the iso as an image, boot with the cd and run the diagnostics in thorough mode. If the diagnostics reveal a faulty hard drive, there's not much you can do other than send the drive out to a professional data recovery company which is expensive.

rknichols · 07-13-2014, 09:26 AM

The output from "blkid /dev/sdb1" and "file -s -k /dev/sdb1" might also be useful.

dstu · 07-15-2014, 12:28 AM

Quote:

Originally Posted by rknichols

The output from "blkid /dev/sdb1" and "file -s -k /dev/sdb1" might also be useful.

The 1st one yields nothing and the 2nd just "data":

Quote:

root@server:~# blkid /dev/sdb1
root@server:~# file -s -k /dev/sdb1
/dev/sdb1: data

dstu · 07-15-2014, 12:32 AM

Quote:

Originally Posted by kilgoretrout

Was this drive part of a raid array?

No. It was on CentOS (I think it was LVM) and I managed to connect it to an Ubuntu server at work and copy part of it, but at a certain point, it stopped working there.

Quote:

There's also a data recovery tool called TestDisk you might want to look into:

http://en.wikipedia.org/wiki/TestDisk

I believe it's in the standard ubuntu repositories. Haven't used it myself but it might be worth a try.

I was told to check testdisk, but use it on a clone (using clonezilla). I'll try that during the weekend, if I don't manage to get this solved earlier.

Quote:

You should also eliminate the possibility that this is a hardware problem. Go to the hard drive manufacturer's website and download their hard drive diagnostic utilities. Seagate, Western Digital and some of the other major hard drive manufacturers provide them for free. You want to get the bootable iso version, burn the iso as an image, boot with the cd and run the diagnostics in thorough mode. If the diagnostics reveal a faulty hard drive, there's not much you can do other than send the drive out to a professional data recovery company which is expensive.

It's indeed WD, so I'll check on their site to see if I find the diagnostics tool.

Thanks for your good advice!!