bsdinstall(8): ZFS install fails if one pick a name for root zpool which exists as file or directory in /. To repeat: 1. start bsdinstall 2. Pick zroot name 'sys' for example 3. Eventually untar fails Suggested resolution is trivial: If new root zpool name is $zroot then mount zroot as /X$zroot, where X is for example 'root'. By default bsdinstall creates similar ZFS structure: NAME USED AVAIL REFER MOUNTPOINT zroot 408M 6.32G 96K /zroot zroot/ROOT 406M 6.32G 96K none zroot/ROOT/default 406M 6.32G 406M / Should be rather if zpool name is 'sys' for example: NAME USED AVAIL REFER MOUNTPOINT sys 408M 6.32G 96K /rootsys sys/ROOT 406M 6.32G 96K none sys/ROOT/default 406M 6.32G 406M /