if ! grep -q -s ntpdate $D/var/spool/cron/root; then
        echo "adding crontab"
        test -d $D/var/spool/cron || mkdir -p $D/var/spool/cron
        echo "30 * * * *    /usr/bin/ntpdate-sync silent" >> $D/var/spool/cron/root
    fi
