Replacing a Corrupt ext2 Superblock

[Holger Rauch <Holger.Rauch@heitec.de>]

Hi!

e2fsck reports that the actual size of an ext2 file system differs from
the size currently stored in the superblock and that the superblock is
likely to be corrupt.

I know that it's possible to specify an alternative superblock when
running e2fsck (-b), but how can I find out where these superblocks are
stored on disk? (This information is provided when running mke2fs, but I'm
wondering how I can retrieve it again.)

Second question: If there is a valid backup of the superblock available on
my drive, how can I replace the obviously damaged superblock? (I recall
that "dd" allows me to do this, but I don't know how the exact command
necessary to replace the superblock.)

Thanks for any help!

Greetings,

	Holger