How to change forgotten Root Password in XenServer
By Sujin Sam Mathews
Reboot the server and wait for the Grub screen.
Once the Grub screen materializes immediately press the button “e” to enter edit mode.
Replace the highlighted portion with the below text as shown in the next image. Even if the surrounding contents appear different it should be ok.
Once this change has been done, press “ctrl” and “X” together to boot into single-user mode.
Within the emergency, mode type the following.
The passwd command will let us input the required password and have us confirm the same. Once completed, Reboot the server again from the Xen console and the newly resetted password must work like a charm.