Internals and Setup
Here's the My Cloud Mirror with the lid popped:
Drives can be easily hot swapped with the device still on, though the swaps are not completely tool-less as you'd have to swap over the screwed in stubs that slide along the internal rails.
Plug in power, connect to your router, give it a minute to boot, and check network devices under Windows. Simple:
Launching from the storage pane (selected above) opens the My Cloud GUI in your default browser:
You are then prompted to set up your My Cloud login. This is the service that lets you 'reach back' to access files on the My Cloud via your mobile devices, or when you are away from home:
After login, you see the My Cloud control panel, which gives all sorts of handy info at a glance:
As an aside, there are tools available from the Western Digital download page:
Pictured is the WD Discovery tool in action:
In case your OS does not see the My Cloud natively, this tool can locate, configure, and even map shares automatically.