Recently one of my colleague forgotten his Linux OEL 5.5 box root password, so he have been successfully re-login his Linux with password reset option available under single user mode.
The steps involved in this procedure as follows
Restart Linux MachineYou are presented with a prompt that looks similar to the following:
|If you use the default boot loader, GRUB, you can enter single user mode. To do so, at the boot loader menu, use the arrow keys to highlight the installation you want to edit and type [a] to enter into append mode.|
Press the Spacebar once to add a blank space, and then add the word single to tell GRUB to boot into single-user Linux mode. The result should look like the following:
Grub append> ro root=LABEL=/ rhgb quiet / single
|Press [Enter] and GRUB will boot single-user Linux mode. After it finishes loading, you will be presented with a shell prompt similar to the following:|
You can now change the root password by typing
You will be asked to re-type the password for verification. Once you are finished, the password will be changed.
Now you can restart your machine by typing init 6, this command will restart immediately