“username is not in the sudoers file. This incident will be reported.”
Aw. Well if you have root access, here’s how to add your user to the sudoers file. This will allow you to simply use sudo instead of su and logging in as root.
su echo 'username ALL=(ALL) ALL' >> /etc/sudoers
The first command will ask you for the root password. The second command adds username to the sudoers file. Replace username with your actual username.