This morning I booted up the PinguyOS linux installed on my VirtualBox (on Windows). I stucked at login page because I do not remember the password. I searched for how to reset pinguyOS linux and ubuntu linux. I found two methods, one method using boot into root bash through recovery boot and the other method directly boot into root bash. First method didn’t work for me as root bash asked for me the password and I don’t know root password. Second method didn’t directly work as well. That article said ‘find line starting with kernel’ and I couldn’t find that one. I figured out and tried the following and I did reset my password.
At boot menu, press ‘e’
go to the end of the line started with
Ctrl+X to boot and you will be in root shell
mypassword and enter
mypassword again to confirm
reboot the machine (changed parameter not persisted)
Now I can log in with my new password