exec.prestart   += "mount_nullfs -o ro  /usr/ports/ /jail/$name/usr/ports";
exec.prestart   += "mount_nullfs        /var/cache/pkg/ /jail/$name/var/cache/pkg";

exec.poststop   += "umount /jail/$name/usr/ports";
exec.poststop   += "umount /jail/$name/var/cache/pkg";