This is a well-known warning message for most of the linux users and it is easy to fix. When we use “sudo su” command to attempt root user login, sometimes this warning appears and doesn’t allow the general user to login. This means the general user is not in the sudoers file.
Error : User is not in the sudoers file. This incident will be reported.
To get rid of this warning message, you should add that user in /etc/sudoers file.
Open /etc/sudoers and add the below content
vi /etc/sudoers sathish ALL=(ALL) ALL
Save and quit the file (Esc + :wq). Now you can login using “sudo su” command.