Just got my 4TB My Cloud drive yesterday. Just trying to figure it out at the moment. I have a 2TB WD external drive I am trying to attach. It has 3 partitions all formatted Mac OS extended journaled (I believe this is the same as HFs+J and should be supported). When attached, it gets nowhere. I get that the WDMyCloud server is shutting down. LED remains blue, but I can do nothing. Only alternative is to unplug/replug. Any ideas?
What happens if you only have a single partition on your drive ? I believe HFS+ is supported on the device what I am not sure of is the multiple partitions are, but lets see if another user can share some information or tips on this matter.
Non-partitioned works fine, I guess. I only have flash drives that are not partitioned. All my external (1 and 2 GB WD) are partitioned.