Gunion(8): a new GEOM utility in the FreeBSD Kernel By: Marshall Kirk McKusick

[@CaseyHancocki3luefire]

I always love talks by Marshall Kirk McKusick

[@ruupertti]

so from the description by McKusick and questions, one could use gunion beneath zfs if wanting to really test zfs by messing (revert after some while) one disk completely and then see after revert how zfs repairs the mess.