sudoers disaster

[Robbo]

On Wed, 2005-09-28 at 21:19 +0200, R.L. Reingard wrote:
> Hello all,
> i guess i did make a great mistake.

Only way to learn!

> cause of the ongoing discussion on Root/Sudo/Passwords, i made an other  
> user, put this new user into the group 'Admin' and tested if this new user  
> can use sudo with its own password. test was okay.
> then i took the default user (which had sudo rights) out of the group  
> 'Admin' and tested if the default user cannot anymore use sudo. test  
> passed.

Are you sure it was Admin, it's case sensitive and should be admin.

> then i switched to the new user AND ... now a sudo with the new users  
> password FAILED.
> no a have two user accounts AND none of them has sudoers rights.
> what the hack is that?

login as the user your know that should have admin rights and type in
groups and check if "admin" is listed.  If it isn't you'll need to add
it using "usermod -G admin username".  To do this (I presume you can't
log in as root), you need to go into single user mode. 

To boot in single mode...

1. You might have to press <ESC> to see your boot menu (you will see a
prompt)
2. Choose the kernel you want to boot using the arrow buttons on your keyboard
3. Press "e" for edit
4. Press the "end" button on your keyboard, type in a comma space ", " and then type "single"
5. Press <ENTER> and than "b" to boot that kernel, this will take you into single user mode