Linux forgot root password

Centos:

1. Press "E" in the Grub Boot interface to enter edit mode

2. Choose Kernel/... And then in the "E"

3. Add "single" to the back. Press "B" again.

4. Enter: "passwd root" to enter the new root password

5, reboot, done

Ubuntu:1, press "E" in the Grub Boot interface to enter edit mode

2, find linux/boot/vm.......ro recovery \nomodeset,

Step 1: Remove recovery \nomodeset

Step 2: At the end of this line add quiet splash rw Init=/bin/bash

3, F10 Save exit

4. Enter: "passwd root" to enter the new root password

5, reboot, done

Linux forgot root password