> Only problem is, you'll lose the contents, and it most probably is the
> RDB header block! In case you wrote down the RDB parameters on paper
> somewhere and can repartition the disk to the same values, you'll
> probably lose everything. 
 
 Yeah, the problem is that I have no saved RDB for these disks - only for
 the internal disks.

> So what you might try, is:
> 
> write a program that reads a block (512 bytes) at offset 0 off the raw disk
> (/dev/rsd3c in this case), and repeats on error, at least a couple of times.
> 
> Once it succeeds, it should:
> 
> a) write that block to a _different_ disk (onto a file!) 
> 
> _Then_ you reassign the block,
> _Then_ you write the saved block back.
> 
> (Hm, a shell loop around dd might work, too).

 Hhm, I've never programmed such low-level stuff before. Will give it a try at
 a moment of leisure :-)

 Thanks!