Linux: Reset root password

[^rooker]

Sometimes you receive a computer from someone else, but they forgot to tell you login credentials.
Here's a short HowTo for resetting the root password to an empty string:

1) boot the computer - until GRUB comes up

2) In GRUB, press 'e' and add the following text to the boot parameters:

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single init=/bin/bash

3) You should now boot into single-user runlevel, ending at a bash prompt as root.

4) Remount the harddisk read-write:

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mount -o remount,rw /dev/hda1

(For further details, look at [DETAILS] section below)

5) Edit /etc/shadow and the password hash for root with nothing. You will find something like this:

root:$1$verylonghashwithlettersandnumbers0:99999:7:::

make it look like this:

root:0:99999:7:::

6) Save the file and reboot. Now you should be able to login as root with no password.


[DETAILS]
1) In case your system disk ain't /dev/hda1, type:

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mount | grep "on / type"

The beginning of the output shows you your device. it might look like this:

/dev/sda1 on / type ext3 (rw,noatime,errors=remount-ro,data=writeback)