Reset a Forgotten Ubuntu Root Password (18.04 & 20.04) in Minutes

Many users set complex passwords that they later forget, locking themselves out of their Ubuntu system. The following steps show how to reset the root password on Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.

Reboot the machine and interrupt the boot process to open the GRUB menu. On a VirtualBox VM, press SHIFT during startup.

In the GRUB menu, highlight the default entry and press e to edit the boot parameters.

Locate the line that begins with linux /boot/vmlinuz. It contains the fragment ro quiet splash $vt_handoff. Replace that fragment with rw init=/bin/bash so the line reads something like: linux /boot/vmlinuz‑... rw init=/bin/bash ... Press Ctrl+X or F10 to boot. The system will start directly into a root shell.

Confirm that the root filesystem is mounted read‑write: $ mount | grep -w / The output should contain rw.

Set a new root password: $ passwd Enter the new password twice. You should see the message password updated successfully.

Resume normal boot by executing: $ exec /sbin/init The system will continue booting into the regular login screen.

After completing these steps you should be able to log in with the new root password. Remember to keep your passwords secure but memorable to avoid repeat resets.