This guide will provide you with an information on how to reset lost root ( administrator ) password on Ubuntu 16.04. This guide assumes that you have the actual physical access to your Ubuntu 16.04 Linux box.
Reboot to Grub Menu
In the first step you need to reboot your Ubuntu 16.04 Linux box to Grub’s menu. If the Ubuntu 16.04 is the only installation available keep pressing
SHIFT after you start your computer until GRUB’s menu appears:
Edit Grub Menu
Once you reboot to Grub menu, select the first menu item or the menu item you normally use to boot your Ubuntu system and press
e to edit:
Alter boot menu
Once in the Grub’s boot menu edit mode use navigation arrows to locate a line starting with
linux and edit it to include read-write mode
linux /boot/vmlinuz-4-4.0-22-generic root=UUID=43ad24d3-e\ c5b-44ee-a099-a88eb9520989 ro quiet splash $vt_handoff
linux /boot/vmlinuz-4-4.0-22-generic root=UUID=43ad24d3-e\ c5b-44ee-a099-a88eb9520989 rw init=/bin/bash
Once ready press
F10 to boot.
Reseting root’s password
If all went well you should now see root shell command line and your root partition should be mounted with read/write flags. To confirm run:
root@(none):/# mount | grep -w /
Now we are ready to reset root’s password. To do so, simply run
passwd command with no arguments. When prompted enter your new root password:
All done. Your root’s password is now reset.
Reboot your system using the following linux command:
root@(none):/# exec /sbin/init
Enter new UNIX password: Retype new UNIX password: passwd: Authentication token manipulation error passwd: password unchanged
Your root partition is mounted read-only. Try:
# mount -o remount,rw /
to resolve this issue.
[ end Kernel panic - not syncing: Attempted to kill init! exit code=0x0007f00
Make sure that you removed
splash boot option when editing grub’s menu item.
When trying to reboot with
reboot command I get:
Failed to connect to bus: No such file or directory Failed to talk to init daemon.
Ignore, and reboot with:
# exec /sbin/init