Adding second my cloud (3TB) for mirroring capability

I have a 3TB My Cloud and want to add a second My Cloud, for redundancy (mirroring). Can this be done, via a cable between the two???

A “Mirror” configuration works in real-time with data copied/removed from linked units at the same time. This is not possible with separate units. What you can do though is use the Safepoint feature to create a backup of one unit into the second one.