Superuser Authentication Failure

Asked by Jack Jebedee on 2006-03-17

Terminal Dialog:

jebedee@jebedee:~$ su
Password:
su: Authentication failure
Sorry.

I just used the very same password to login and it worked fine. I don't have another password combination on the machine. I'm the only user. I rebooted and the problem didn't change.

Question information

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English Edit question
Status:
Solved
For:
Ubuntu gnome-terminal Edit question
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Solved by:
Jan Hülsbergen
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Jan Hülsbergen (jan-afoo) said : #1

Did you use the password to login as jebedee or as root?

Normally, Ubuntu disables the root account and encourages you to use sudo (and your users password) for actions that need root rights. If you need a full root shell, you can use 'sudo -i'.

For su to work, you first have to create a password specificaly for root using 'sudo passwd'.

HTH

Jack Jebedee (jebedee) said : #2

Thanks for the heads-up, Jan. I just finished re-reading RootSudo in the Wiki and (Bonk!) now I know what it's talking about. My adventure involves installing the latest Opera (my favorite!) web browser and the Opera docs specified the SU command. I'll try it again when I get home, but I'll use SUDO instead. I appreciate your good advice, Jan.

mciancio (mciancio) said : #3

If you want to use 'su' instead of sudo to gain root privileges, you must:

1) assign a password to root: 'sudo passwd root'
2) setuid /bin/su: 'chmod 4750 /bin/su'

root@xxx# ls -la /bin/su
-rwsr-x--- 1 root admin 32796 2006-12-19 21:35 /bin/su

Now you have enabled the root account and you can 'su' from every user belonging to admin group.

Yes, I know that 'sudo' may be more secure, but there are some situations in which it's more useful to 'su' than to 'sudo'.

akshay jain (jainer413) said : #4

mciancio thanks!!
it helped a lot i was using fedora before now kubuntu!

akshay jain (jainer413) said : #5

mciancio thanks!!
it helped a lot i was using fedora before now kubuntu!

siddharth jain (akshay-jain-p) said : #6

hii

Hi everybody, last time i starte in terminal my Ubuntu 8.10. But when i try tu ge su acces, i got a problem like this:
joel@joel-laptop:~$ su
Password:
su: Authentication failure
joel@joel-laptop:~$ su
Password:
su: Authentication failure
joel@joel-laptop:~$ su
Password:
su: Authentication failure
joel@joel-laptop:~$ su
Password:
su: Authentication failure
joel@joel-laptop:~$ su
Password:
su: Authentication failure
joel@joel-laptop:~$ sudo password root
[sudo] password for joel:
sudo: password: command not found
Can somebody tell me abou this case(I am newbie in linux)

pecija (ibura) said : #8

assign a password to root: 'sudo passwd root'