Can I connect usb mybook 4gb to mycloud 2gb for extra storage?

I recently purchase a My Cloud 2GB and then purchase 4GB MyBook and would like to connect it to my cloud but, I cant see the extra storage on my network. What do I have to do so, I can see this drive.

Hello,

Check page 85 Of the WD My Cloud User’s Manual.

Thank you for the info. Right after I made the post I figured this out.