# zpool create tank c0t0d0
# zfs create tank/fs

# mkfile 100m /tank/fs/foo
# df -h /tank/fs
Filesystem             size   used  avail capacity  Mounted on
tank/fs                 80G   100M    80G     1%    /tank/fs
		

# zpool create tank c0t0d0 c1t0d0