Reset debian root password through KVM

Boot into grub, select single user but do not press enter.
Press e to bring you into edit mode.
Scroll down to the kernel line, it starts with “linux /boot/vmlinuz-2.6…….”
Scroll to the end of that line and press space key once and type

init=/bin/bash

Press Crtl x to boot

Then type

mount -rw -o remount /

Now you can right to disk and change password or whatever else you want

----------------------

referece:

https://derwynd.com/2011/04/14/debian-squeeze-change-root-password/