watch out for the "tohd" cheat code

[OErjan]

have you tried a lowlevel format? or perhaps first a "zeroing" of the disk (if that is not enough try low level formating).

dd if=/dev/zero of=/dev/hd bs=512

these actions will WIPE the ENTIRE drive fairly well.
any atempt at data recovery after the fact will not be easy, some might say near impossible.
you might recover fragments of files after this, perhaps even whole files, but it will cost you time/money/hairloss/ulser... so be carefull.