Lost Password
The following applies to most linux boxen. It can be used to recover a lost password and is also called "rooting" the box.
GRUB method
Edit the grub boot commands.
- start the computer booting up, and hold down the right shift key.
- After a few (or 10 or 20) seconds you will see the grub menu, which is characterized by a lines that will say ...kernel 2.6...
- Hit the down arrow once to get to a line that ends with recovery mode and press enter.
- This will bring up a menu with many options. The two that you're looking for are netroot and root. Netroot will set up networking on the machine, and then drop you to a root shell. root will just drop you to a root shell without any further setup.
- select either netroot or root from this menu. If you get a message that says "Give root password for maintenance (or type Control-D to continue):" then you have a root password set. Enter the root password here or if you don't know the root password follow the instructions under here
- You will be given a line at the bottom of the screen that should say root@freekbox:~#
- at this prompt, enter passwd yourusername (replace yourusername with the username you're trying to reset, or "oem" if it has not been changed).
- If you don't know the accounts username you can type ls /home for a list of all accounts on the computer.
- It will request that you enter a new password, and then once more to confirm. The screen will not show input as you are typing.
- once you enter your new password it should tell you "passwd: password updated successfully"
- type reboot to restart the computer.
live CD method
If the box does not use grub to boot, one can boot the box using a live cd or a System Rescue CD (download one here), then login as root (not necessary with System rescue CD) and proceed by entering the following commands one by one (hit enter after each line).
mount /dev/sda1 /mnt chroot /mnt passwd username (replace username with the username you're trying to reset, or "oem" if it has not been changed. sync reboot
To find your username you can use ls /home
For Macs
For Mac computers at the yaboot prompt enter:
Linux rw init=/bin/bash
Once you get to the # prompt you will need to reset the terminal
reset
Now check the username
ls /home
and reset the users password
passwd usernamehere
Reset root password
- start the computer booting up
- After a few (or 10 or 20) seconds you will see a screen that says... Grub Loading...3..2..1.
- During this screen, quickly press Esc, to go to the grub menu
- Next you will see several lines that start with Ubuntu, kernel 2.6..., this is the GRUB menu.
- Select the first line in the list and press 'e'
- You should see something along the lines of
root (hd0,0) kernel /boot/vmlinuz-2.6.24-27-generic root=UUID=3deb56... ro quiet splash initrd /boot/initrd.imb-2.6.24-27-generic quiet
- Select the second line and press 'e' again.
- Remove 'ro quiet splash' from the end of the line and add 'rw init=/bin/bash'. Hit enter.
- Press 'b'. The box will now boot up and you will get a prompt that says 'root@(none):/#'
- At the prompt enter
/usr/sbin/usermod -p '!' root
Restart the computer.
Reset Root password CD version
This method involves editing /etc/shadow by hand to get rid of the password.
- start the computer and insert the system rescue CD for the password reset.
- mount the directory by typing mount /dev/sda1 /mnt
- edit /mnt/etc/shadow with vi
- remove everything between the first and second colons (:) and replace it with ! (exclaimation mark)
- reboot the tower and remove the system rescue cd