I recently bought a Dell Poweredge r610, and I created a bootable USB stick for Ubuntu Server. It was bought used, and I do not know if someone had already installed some other OS on it.
When I started setting it up, it worked fine. After I selected Use the Entire Disk, it showed the screen to pick a disk. None showed up. The drive is a 500GB SATA Seagate Barracuda installed in Slot 1. A little light on the side is green, although I may not have installed it right.
I don't know what other posts mean by using things like the Terminal, since there's no option for that.