Steps to reproduce: 1. Create a beadm(1) backup (or manual clone) of a zfs root+boot dataset 2. Delete the /boot directory in the live system 3. Reboot Result: the loader dies (because /boot/lua/loader.lua doesn't exist). It is, however, possible to recover in this situation with the following commands: 1. set currdev=zfs:zroot/ROOT/backup: 2. include /boot/lua/loader.lua (See a full description here: https://forums.freebsd.org/threads/boot-directory-deleted-how-to-recover-with-zfs-backups.79181/ ) Instead of dying instantly, the loader might try finding a valid /boot directory on another dataset (e.g. siblings to zroot/ROOT/default) and offer (or try) to load from them.