For 2.11BSD on the PDP-11, in the stand alone utilities that are found on the installation tape, the storage devices are named:
dn(x,y,z) where dn is the mnemonic for the driver, x is the controller number, y is the unit number and z is the partition on the unit. So the first partition on the first drive on the first MSCP controller is ra(0,0,0). It's fairly easy form the install tape to disklabel and mkfs a drive on a second controller. Once UNIX is running, things change. The devices in /dev are named ra0 for the first unit on the first controller, ra1 for the second unit on the first controller and etc. I don't see a way in the naming convention to identify other controllers. My question is, what is the device name in /dev for the first drive on the second controller?