Currently we have root account without password, and we are using that account for SSH connection. We need to set 
password and make it disabled when the password entered incorrectly 3 times.

To set a password for root user, I have tried passwd command, but it raises always "System Error", I have changed the "
passwd" commands rights to include 's' privilege. But it did not solve the problem.
What should we do to set password for a user?