Probably Debian, but it depends on the workload. I'm not sure why you'd need a guide to "setting up" a complete, prebuilt 1U server or what it would even consi

Probably Debian, but it depends on the workload. I'm not sure why you'd need a guide to "setting up" a complete, prebuilt 1U server or what it would even consist of. "Plug in the power cable and press the power button, then use your USB keyboard and USB mouse to get into the BIOS, where you rearrange the boot order to select from your USB flash drive"? Same as any other prebuilt computer. Unless I'm misunderstanding the question somehow?