How To Reset A Forgotten Raspberry Pi Password

by Prashant Kumar Sharma

I’ve got a Raspberry Pi running in my garage as part of a security system. It’s been running for so many months that I forgot the password so I was unable to access it via SSH.

Luckily there is was a technique that I could use to reset the password and get it back up and running. You need physical access to the SD card, a separate PC and the ability to connect your Pi to a monitor and keyboard. I used a Windows PC but this should work fine on a Mac or Linux machine.

 

Step 1 – Grab The SD Card

Power down the Pi and remove the SD card. Insert it into your PC.
Step 2 – Edit cmdline.txt

The boot partition should be visible and contain a file named “cmdline.txt”. Edit this file in a text editor and add the following to the end of the existing text :

init=/bin/sh

If the original content was :

dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait

It should now look like :

dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait init=/bin/sh

Make sure it is all one line! Save the text file and eject the SD card from the PC.

Step 3 – Reset the Password

Insert the card into a Pi that is connected to a monitor and keyboard. Power up the Pi. There may be a delay but you should be presented with a flashing cursor.

At the prompt type the following command :

passwd pi

You will then be prompted for a new password. Enter it carefully and press the [Return] key. It will now ask you to retype the password.

reset_lost_password

The password has been changed.

Now type the following commands :

sync
exec /sbin/init

The Pi will continue to boot and return you to the normal command line prompt.

Shutdown the Pi and power it off.

sudo halt

Step 4 – Edit cmdline.txt

Using the PC edit the “cmdline.txt” file again and remove the “init=/bin/sh” text you added in Step 2.

You can now return the SD card to your Pi, reboot and use the new password.

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