If you have forgotten the root password it is possible to set a new one by interrupting the boot process at the GRUB stage and forcing the system into run level 1 (single user mode).

1. Launch the KVM interface for your server to access it from the console.
2. Interrupt GRUB by typing a character such as “space”
3. Append to the kernel line by typing “a”, backspacing through “rhgb quiet” and appending “1” and pressing <enter>.
4. This will give you a root shell and not a login prompt. From there you can use the “passwd” command to set a new root password.
5. Restart the server and allow it to boot normally.