"Guessing" superblock parameters

[Sander Steffann]

Hi,

> > Is the filesystem (offset of inode tables, ...) the same everytime I
> > format the same partition? If not, why?
> 
> Yes, this is generally true for a given blocksize.  Even the 
> journal is created after the inode tables are allocated.  
> However, as part of the mke2fs the inode tables are zeroed, 
> so this would in fact be bad in your case.

You can use the -n option:

       -n     causes mke2fs to not actually create a filesystem, but
display
              what  it  would do if it were to create a filesystem.  This
can
              be used to determine the location of the backup superblocks
for
              a  particular filesystem, so long as the mke2fs parameters
that
              were passed when the filesystem was originally created are
used
              again.  (With the -n option added, of course!)

Good luck,
Sander.