Ask Ubuntu is a question and answer site for Ubuntu users and developers. 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 get the root privilege when I type sudo.

But when su asks for the Password, which I type in, the terminal says

su: Authentication Failure
share|improve this question
up vote 6 down vote accepted

Open Terminal By CTRL+ALT+T and Type :-

sudo passwd

And Re-Enter your password. This command will have you change your current password.

share|improve this answer

You could just use sudo su

$ sudo su

or sudo -i / sudo -s

$ sudo -i 
$ sudo -s 

Both work fine and will do everything .

share|improve this answer

Try to change the password of the sudo and login

$ sudo passwd    
[sudo] password for dhamu:
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully

After changing the sudo passwd you will be able to switch user via su

$ su
share|improve this answer

You can just use

sudo -i

Then just enter your password to get root privilege.

share|improve this answer

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.