Comment 4 for bug 668561

I followed Richard's idea. However, I get this message:
e2fsck -y -f -v /dev/sda1
e2fsck: Bad magic number in super-block while trying to open /dev/sda1
/dev/sda1:
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>

Per the request, I tried e2fsck -b 8193:
e2fsck -b 8193 /dev/sda1
e2fsck: Bad magic number in super-block while trying to open /dev/sda1
/dev/sda1:
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>

I have also tried e2fsck -p /dev/sda1 and have received the same result. An interesting thing is that it mentions ext2. I have Ubuntu 10.04 LTS and so I have ext4. I wonder if I'm supposed to specify somewhere that it's ext4.
Thanks in advance!