Reset Linux root Password

METHOD 1

1. Boot the computer with Linux Installation CD.
2. Enter into Linux Rescue mode by enering the following command in boot screen. boot: linux rescue
    3. When the sh prompt is reached, enter the following commands to change root password.

#chroot /mnt/sysimage
#passwd
#exit
#reboot

METHOD 2
Oracle Enterprise Linux forgot root password

Press F2 when the splash screen comes up

A GRUB screen will display

enter the letter 'e' (without single quotes)

Using the arrow keys, move the cursor to the line for kernel

enter the letter 'e' again

You will see a command line

after the last word/character append a space and the word single (single mode)

Hit Enter

Make sure the cursor is on the kernal line

enter the letter 'b' (this will boot)

System will load into single mode, should see

Enter passwd

Enter new password two times

Enter exit (this will reboot)

Test the new root password