Hello fello nixers,
This thread is about what to do if you lost your root password.

Context: My friend lost his root password and his current user automatically logs into the system without entering any password, so he doesn't remember this one either.

The solutions I could think of:

• Boot from a live CD and edit the /etc/passwd to make his default user have root privileges, check validity of the file with pwck, log back in to change the root password, set everything back to normal.
  
• Boot from a live CD and edit /etc/shadow to put a hash I'm sure of or an empty one. (I've been looking but couldn't find a tool that generates that password so I'm just going to copy it from another box).
  
• Boot from a live CD and change the sudoers file to allow his user to be root without entering a password.
  
• This doesn't apply here but for BSDs booting into single user mode allows changing the root password. ( https://www.openbsd.org/faq/faq8.html )
  

This will only work if the hard disk is not encrypted, and it's not so it's fine.

I have found those too:
https://access.redhat.com/documentation/...asswd.html
This one is a way to boot into single user mode linux by appending to the GRUB line:
It then gives you a root shell where you can change the password.

http://askubuntu.com/questions/24006/how...e-password
https://help.ubuntu.com/community/LostPassword

Kind of the same spirit, choosing to boot into a rescue mode and then mounting the file system and changing the password.

There's also a mention to add this line to the grub:
Which I assume will use bash as the init process and thus letting you have full control over the OS (source and here).

Do you have any other tips or suggestions?

Here's a bunch of resources on the topic.