Partition not recognized by mount

[Coywolf Qi Hunt]

On Sat, Apr 15, 2006 at 01:54:05PM +0200, julius Junghans wrote:
> Hi,
> 
> somehow after a power failure i can't mount my ext3 partition :(
> 
> mount /dev/hdd2 /mnt/gentoo/
> mount: you must specify the filesystem type
> 
> fdisk /dev/hdd
> 
> The number of cylinders for this disk is set to 484521.
> There is nothing wrong with that, but this is larger than 1024,
> and could in certain setups cause problems with:
> 1) software that runs at boot time (e.g., old versions of LILO)
> 2) booting and partitioning software from other OSs
>    (e.g., DOS FDISK, OS/2 FDISK)
> 
> Command (m for help): p
> 
> Disk /dev/hdd: 250.0 GB, 250059350016 bytes
> 16 heads, 63 sectors/track, 484521 cylinders
> Units = cylinders of 1008 * 512 = 516096 bytes
> 
>    Device Boot      Start         End      Blocks   Id  System
> /dev/hdd1               1         970      488848+  83  Linux
> /dev/hdd2             971      155114    77688576   83  Linux
> 
> 
> mount -t ext3 /dev/hdd2 /mnt/gentoo/
> mount: wrong fs type, bad option, bad superblock on /dev/hdd2,
>        missing codepage or other error
>        In some cases useful info is found in syslog - try
>        dmesg | tail  or so
> 
> 
> dmesg:
> VFS: Can't find ext3 filesystem on dev hdd2.
> VFS: Can't find ext3 filesystem on dev hdd2.
> 
> 
> What can i do to get my data back?
> 
> Julius

What were you doing before the power failure?

I have had lost my super block before too. And I did get my filesystem back.
To get your filesystem back, you need to locate your backup superblocks.
I wrote a simple program to find my superblock last time.  There is also one
in the e2fsprogs source package. Then you could use dd(1) to copy your backup
sb onto your primary sb. Or you could try mount with sb=n option. Good luck.


	Coywolf