How to Reset The Root Password in Linux

This blog post illustrates three methods to break the root/grub password

METHOD 1

HOW TO RESET UR ROOT PASSWORD IF U FORGET IT

While Booting ( Redhat ) just press "e" in GRUB

u will find 3 lines of code.

Goto to the 2nd line press "e" again and type "1" in the end

then press ENTER.

Then press "b" and it will boot you into your shell.

Just type "passwd" and change your ROOT password...

don't need to know the old one.


METHOD 2

"I, uh, forgot the root password"

Let's look at recovering the root password from the boot loader. If you're using GRUB, then, as GRUB loads up, highlight the Red Hat Linux entry on the GRUB menu and then press [E] to edit the boot configuration. Locate the following line, something that looks like this:

kernel /boot/vmlinuz-2.4.20-0.70 root=LABEL=/hdc=ide-scsi

Type the number '1' at the end. Doing so boots the PC into run level 1-single user mode, where you're automatically logged in as root. This done, type 'passwd' at the prompt. You can enter a new password here.


METHOD 3

To break the GRUB start-up password, follow the steps given below:

1. Boot the system with the first Linux CD. At the boot prompt, type linux rescue to switch to rescue mode. In rescue mode you will be asked if similar steps should be followed, which need to be followed in the installation. Once you get the # prompt, type the following command:

# chmod /mnt/sysImage

2. Edit the grub.conf file and remove the passwd line from the file. Save the file and exit.

3. Once your machine reboots, you will be able to start your Linux OS in the usual manner.