I am new to Linux and I have CentOS running on a dual boot system. I was trying to edit a file requiring root permissions, so I used sudo. I typed the root password and it failed. This happened three times, and the process was ended. I then logged in as root (su) and was able to navigate to the file and make changes as root. Am I missing something? How would I edit the sudoers file such that this password would work? Or is there another way to log in to the sudo group to make these changes? How do I set sudo passwords?