kazulog@sv1:~$ sudo passwd -l root
passwd: password changed.
kazulog@sv1:~$ sudo passwd -S root
root L 2026-09-10 0 99999 7 -1
kazulog@sv1:~$ sudo grep '^root:' /etc/shadow
root:!$y$j9T$ZwiZAHFi9TMLave282yGC.$h.9O6DniClLZm3k/ot2dm8kKDhq6EbgbuhIIWiTUBvA:20706:0:99999:7:::
kazulog@sv1:~$ su -
Password: 
su: Authentication failure