>> Ultra 2: failed - no CDROM driver found
> Ultra 2: same as the ultra 450, scsi cdrom correct?
Back in February, on my Ultra 1, I couldn't install from CDROM either. After bootstrapping the system from a 32 bits install, I only needed the sun_esp module in the initrd for everything to work fine with kernel 4.3 (modulo X11 on the FFB, I posted a patch). I assumed that the installer had the same issue. I recently installed kernel 4.6, seemed to work fine as well (I didn't stress-test the system, but I could log in X11 with WindowMaker as the window manager).