How to Reset Root Password on CentOS 6.4/Redhat

When we forgot password root on Centos, we can reset that password easily. We have to use single mode to do that.
STEP 1. Boot Computer and Interrupt while booting at GRUB stage hitting ‘arrow‘ keys or “space bar“.

Booting GRUB Stage

STEP 2. Type ‘a‘ to modify kernel argument. Anytime you can cancel typing ‘ESC‘ key.

Modify Kernel Argument

STEP 3. Append 1 at the end of “rhgb quiet” and press “Enter” key to boot into single user mode.

Append 1 at the Screen

STEP 4. Type command “runlevel” to know the the runlevel where you are standing. Here “1 S” state that your are in a single user mode.

Type Command runlevel

STEP 5. Type ‘passwd‘ command without username and press ‘Enter‘ key in command prompt. It’ll ask to supply new root password and re-type the same password for confirmation. “Your are Done”

Congratulation!!!