f you have an available dual-port and an available quad-port adapter, the dual-port adapter should be used first.
If you only have an available quad-port adapter and you are hot-adding a single loop of disk shelves, then Ports A and B are defined as a port pair and Ports C and D are defined as a port pair. For the purposes of incorporating redundancy, Module A connects to Port A or Port B and Module B connects to Port C or Port D.