Thank You for Your time and answer, Arno: > a) locking the root account (passwd -l root), which will give you > "sulogin: root account is locked, starting shell" That's the point - sudo is used on the system and the root account is blocked. So, what's the strategy to protect systems in such cases as mine when root account is blocked? Why, for example, the sudoers users are no asked for their passwords, if You know?