@SaTurn-> s zfs create -p zroot/srv/jails/foo
@SaTurn-> s zfs set mountpoint=/srv zroot/srv
@SaTurn-> fetch ftp://ftp.freebsd.org/pub/FreeBSD/releases/amd64/amd64/12.2-RELEASE/base.txz -o /tmp/b.txz
@SaTurn-> sudo tar xf /tmp/b.txz -C /srv/jails/foo
@SaTurn-> s rm /tmp/b.txz