How to reset root password Ubuntu
Changing the root password on Ubuntu requires access to the console. You can use these steps to change the root passwords on all Debian derivatives.
1 – Power on the system. You should see the grub menu when booting your system.
2 – Press “e” to edit the grub menu. The following screen should appear
3 – Find the line that starts with: linux /boot/vmlinux….
4 – Go to the end of the line and type:
init = /bin/bash
5 – Now, press CTRL+X or F10 to boot your Ubuntu system.
Once you have reached the bash prompt, type the following commands to mount the file system in rw mode.
mount -o remount, rw /
Now, change the password using command:
Reboot your system
That’s it. Now you can login using your new password