USB Hub Compatibilty

I am searching for a powered 3.0 usb hub to use with our personal cloud.  We intend to plug 2 passport drives into the hub.  In shopping for a hub I came across a statement that the particular hub is not compatible with a WD Passport!!  What should I be looking for?

Hello,

As you can see on the My Cloud manual up to 7 devices can be connected with a powered USB hub. In order for you to know which external hard drives are compatible, I recommend you to first check the compatibility for the Hub.

Compatibility was the point of my post.  How does one ascertain compatibility of a hub?  Does WD have a list?  Does anybody?  In shopping for a hub I have not found anybody who was even aware of a hub compatibility issue.

Hello,

WD does not have a list of supported powered USB hubs and the My Cloud manual only states that it needs to be powered.