Meh, none of my 3 #SGI #Indigo2 do boot:
- Impact: cannot find system
- Extreme 1: you hear that clicking sound of dead disk, eh?
- Extreme 2: nope, no system, but how about that nice CD-ROM drive in there and your boot medium? HAHA! Just kidding... won't let you read those but ejecting them immediatedly...

Seems as if I need to go the netboot way...