Power out during software-installation from usb to external hard drive [closed]
And now trying to boot brings up gnu grub... i have no idea what to do.
Because the power went out during the OS installation there's no way to get installed software on the external hard drive back the way it was. Your best option is to start over and reinstall Ubuntu on the external hard drive. The Ubuntu live USB has GParted partition editor built-in which can be run when trying Ubuntu in a live session, but in most cases it is easier in to set the Ubuntu partition(s) from the Ubuntu installer.