when using sudo command, I met the error: "uers-name is not in the sudoers file, and this incident will be reported". And then I tried some answers in the internet, such as "su root " and so on and then I got the error"su:authentication failure". I knew there were many questions and answers about "not in the sudoers file" and "su:authentication failure" respectivley, but discussions are often like this:
- as for "not in the sudoers file", the answer referred to "su root"
- as for "su:authentication failure",the answer referred to"sudo" however, I met first "not in the sudoers file", and then follow instructions "su root" or "su -i",and I got error"authentication failure" , then some answers says to some"sudo" command to solve the "authentication failure". I couldn't use the "sudo" command, how could I use this to solve the "authentication failure" problem? Doesn't this mean a snake want to chase its tail? So far, I didn't see any answer that can explain explicitly about this problem and really have been stuck in it some time. Could anyone please give me clues on this?