Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I just recently installed Ubuntu 11.04 on my desktop, and I only entered in one password during the install process. This password works to log into the machine, run updates etc. When I open up the terminal, and try to use su and I enter in the same password... I get an Authentication failure.

I've booted my computer up in recovery mode, and reset the password from the command line, but I'm still getting the same authentication error.

If anyone could help me out, I would appreciate it.

share|improve this question
I'm sorry but have you even bothered to google or read documentation? – Server Horror Sep 24 '11 at 16:41
I figured with as obvious as the answer was there would have to be one guy that would say something like that. sigh Now that I know the answer, I'm able to better phrase the question so that google pulls up more relevant results... but that didn't help me when I was looking through page after page of tutorials on how to reset the root password. – Troy Knapp Sep 24 '11 at 17:53
up vote 3 down vote accepted

In Ubuntu the root account is locked by default. To perform administrative tasks in Ubuntu you need to use sudo instead. If you need a root shell, use sudo -i.

Of course you can just unlock the root account with sudo passwd root but after that you are not doing thing 'in Ubuntu way'. Is that a good thing or not, you decide.

share|improve this answer
This worked great, thanks! – Troy Knapp Sep 24 '11 at 13:38

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.