[nitrogen]

Works even when your hard drives are severely damaged and you just need to /bin/dd some raw sectors.

That reminds me of the time when some partitioning utility overwrote the first block of my filesystem and then set the filesystem start to the wrong block. I thought I was hosed, but I managed to use hexdump to find a backup superblock, calculate the correct filesystem offset from that, and dd the backup superblock into the primary location. I may be misremembering some details.