How to do backup from my ex4 to ex2 cloub?

My Cloud OS 3 Personal & Network Attached Storage My Cloud EX4
#1

How to do backup from my ex4 to ex2 cloub?

#2

Try from this manual http://setup.wd2go.com/?mod=faqs&device=mcp4&faq=backItUp

Back up data to another WD My Cloud EX4 in or outside your network