Also all my jail install directories are ZFS datasets. (and created as closely as I could to match the handbook section 15.5)
Code:
user@JailHost:~ % zfs list | grep jails
NAME USED AVAIL REFER MOUNTPOINT
jpool/jails 2.59G 56.0G 45.3K /jpool/jails
jpool/jails/j 2.59G 56.0G 1.89M /jpool/jails/j
jpool/jails/j/mroot 2.59G 56.0G 2.59G /jpool/jails/j/mroot
jpool/jails/js 1.92M 56.0G 41.3K /jpool/jails/js
jpool/jails/js/www 1.88M 56.0G 1.88M /jpool/jails/js/www