14.Set root user password

Input following command:

xxxxxxxxxx
sudo passwd root

After executing this command, the system will prompt you to enter the root password twice. Just enter the password you want to set, and then execute

sudo passwd --unlock root

After executing this command, the system will prompt you to enter the root password twice. Just enter the password you want to set, and then execute

​x
su

The root user is successfully unlocked.