scrub: -X argument cannot exist
This had me stumped because I read it as "the -X argument cannot exist", which seemed to make no sense whatsoever. And indeed it means "the argument to -X cannot be a directory that exists". Simply running it with a new directory, like so:
root@server:/home# scrub -X /home/scrub scrub: using NNSA NAP-14.x patterns scrub: scrubbing /home/scrub/scrub.000 1073741824 bytes (~1GB) scrub: random |..^C |
It is notable that more current versions of scrub fix the error message to be more intuitive (mine was still 2.2).