If your can’t remember a ROOT password or if the f**ing sysadmin has changed it without notification, you can reset the ROOT password if you have physical access to the machine console.
Here is how to, based on SuSE Enterprise 10 Linux machine.
- Power on the Machine
- When boot menu comes, press F2
- In the Boot Option, type ‘init=/bin/sh’ and start the OS
- A console will come
- Type ‘mount -a’
- Type ‘passwd’
- Change password