I’m posting this in both the My Cloud and My Book forums as it is most likely to do with both.
I have just bought a My Book 8TB external hdd, thinking it would be just a matter of connecting it to the usb 3 port on my existing My Cloud. I connected it to my pc first and it ran a setup app on startup. Then when I connect it to the My Cloud, its not being recognised.
Is it possible to use the My Book the way I want?