Most of the time, the whole point of ZFS is that your data does not get corrupted. But during development you sometimes need the opposite: a controlled, reproducible corruption, so you can watch self-healing kick in, see what a scrub reports, or just understand how a file maps onto the physical disk. There is no better exercise than breaking one byte on purpose and seeing ZFS struggling.

The safe rule is simple: do this only on throwaway pools backed by throwaway files. Pointing these commands at a real disk would be less of a lesson and more of a confession.

This is the story of doing exactly that on Linux, the lazy way and the educational way.