What is the best/safest way to fix a bad ND partition

[Alexander Dupuy]

If the ND filesystems are the same size and are on the same disk, the best
way is to use dd(1) - something like "dd if=/dev/rndl1 of=/dev/rndl2
bs=126b" works well, and quickly - don't worry about the I/O error when it
hits the end of the first ND partition.  Otherwise you should do an rm -rf
or a mkfs on the second ND partition, and then use a dump | restore
pipeline.

@alex