Ubuntu 20.04 重置 root 密码

The objective of this tutorial is to reset a lost root or user password on Ubuntu 20.04 Focal Fossa Linux.

In this tutorial you will learn:

Ubuntu 20.04 reset root password

Software Requirements and Linux Command Line Conventions
Category	Requirements, Conventions or Software Version Used
System	Installed Ubuntu 20.04 or upgraded Ubuntu 20.04 Focal Fossa
Software	N/A
Other	Privileged access to your Linux system as root or via the `sudo` command.
Conventions	# – requires given linux commands to be executed with root privileges either directly as a root user or by use of `sudo` command $ – requires given linux commands to be executed as a regular non-privileged user

步骤一

The first step is to reboot into the GRUB menu. If Ubuntu 20.04 is the only operating system installed you need to keep pressing SHIFT for the GRUB menu to show up. Next, while your Ubuntu boot menu is highlighted press e to edit the Grub’s boot prompt.
步骤二

Using your navigational arrows locate the line containing the following string ro quiet splash $vt_handoff
步骤三

Replace the string ro quiet splash $vt_handoff with the following text rw init=/bin/bash. Once you have made the change press F10 to initiate the regular boot sequence.
步骤四

After the successful boot you should be welcomed with a root’s shell without a need to enter the root password
步骤五

Confirm that the root (/) partition is mounted as rw. To do so execute the mount | grep -w / command.
步骤六

At this point we are ready to reset the root password. To do so simply execute the passwd command and follow the instructions. In case you need to reset your user password, simply execute the passwd followed by your username.
步骤七

All done. Your root password should be now recovered. All what remains is to reboot your Ubuntu 20.04 system. To do so execute the 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 the splash boot option when editing the grub’s menu item.

When trying to reboot with the 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