Ext3 users - Nov 2006 - e2fsck: Bad magic number in super-block

I posted this to the Fedora-list, but thought I might get some 
additional information here as well.

I have a HD that refuses to mount with a 'bad magic number in 
super-block'. I'm running FedoraCore 6 x86_64.

[root at moe ~]# fdisk -l /dev/hdc

Disk /dev/hdc: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

    Device Boot      Start         End      Blocks   Id  System
/dev/hdc1   *           1          13      104391   83  Linux
/dev/hdc2              14        9729    78043770   8e  Linux LVM


[root at moe ~]# mount -t ext3 /dev/hdc2 /Big-Drive/
mount: wrong fs type, bad option, bad superblock on /dev/hdc2,
        missing codepage or other error
        In some cases useful info is found in syslog - try
        dmesg | tail  or so

[root at moe ~]# e2fsck -b 11239425 /dev/hdc2
e2fsck 1.39 (29-May-2006)
e2fsck: Invalid argument while trying to open /dev/hdc2

The superblock could not be read or does not describe a correct ext2
filesystem.  If the device is valid and it really contains an ext2
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>

[root at moe ~]# !624
mke2fs -n /dev/hdc2
mke2fs 1.39 (29-May-2006)
Filesystem labelOS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
9764864 inodes, 19510942 blocks
975547 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
596 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
         32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 
2654208,
         4096000, 7962624, 11239424


I've tried 'e2fsck -b (superblock) /dev/hdc2 on all the superblocks 
listed above to no avail.

I've read about 'mke2fs -S' as being a possible solution, however I
see
that it is recommended as a last resort. Therefore I have held off on 
trying that method.

I'm afraid I'm toasted, however I'm still hopeful that I might
recover
some (or all) of my data.

Have I overlooked something?

Thanks,
Mike

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On Tue, Oct 31, 2006 at 08:15:30PM -0500, M. Lewis
wrote:
> I posted this to the Fedora-list, but thought I might get some 
> additional information here as well.
> 
> I have a HD that refuses to mount with a 'bad magic number in 
> super-block'. I'm running FedoraCore 6 x86_64.
> 
> [root at moe ~]# fdisk -l /dev/hdc
> 
> Disk /dev/hdc: 250.0 GB, 250059350016 bytes
> 255 heads, 63 sectors/track, 30401 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> 
>    Device Boot      Start         End      Blocks   Id  System
> /dev/hdc1   *           1          13      104391   83  Linux
> /dev/hdc2              14        9729    78043770   8e  Linux LVM
are you ABSOLUTELY SURE that /dev/hdc2 really containt DIRECTLY the ext3
filesystem ?

By FDISK output, it looks like it is not ext3 partition, but a physical
volume controlled by LVM, so you should use LVM tools to find real data
(vgscan, vgdisplay, pvscan, lvscan, ...)

the ext3 partition you are looking for is probably on logical volume on that
LVM...

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