Don't worry about the Ramacs. I have Suse 8 loaded on both 3380 and 3390 Ramac Dasd Subsystems, as well as MP3000 internal dasd.
I haven't had to add disk. Mine were added durning installation. I assume that you went to the Suse website. There is a paper on adding S390 dasd to a running Linux system. That worked for me when I added dasd to Linux 7. Tom Duerbusch THD Consulting
