mention the firewall issue

        rsync -P $KVM_HOST:/srv/vmstore/$INSTANCE/$INSTANCE-root /srv/

        rsync -P $KVM_HOST:/srv/vmstore/$INSTANCE/$INSTANCE-lvm /srv/ || true

    it's possible there is not enough room in `/srv`: in the base

    Ganeti installs, everything is in the same root partition (`/`)

    which will fill up if the instance is (say) over ~30GiB. In that

    case, create a filesystem in `/srv`:

    Warning: the FSN nodes don't have SSH access everywhere due to a

    flaw in our installation process ([ticket #33143](https://trac.torproject.org/projects/tor/ticket/33143]). You will

    need to manually allow them to connect with iptables before the

    above will work, on the KVM HOST:

        iptables -I INPUT -s $SPARE_NODE -j ACCEPT

    Note: it's possible there is not enough room in `/srv`: in the

    base Ganeti installs, everything is in the same root partition

    (`/`) which will fill up if the instance is (say) over ~30GiB. In

    that case, create a filesystem in `/srv`:

        (mkdir /root/srv && mv /srv/* /root/srv true) || true &&

        lvcreate -L 200G vg_ganeti -n srv &&