Extending capacity with a USB HDD

I have 4Tb MyCloud device working beautifully and am loading my Videos onto it. It is now 3/4 full so I bough a 4TB external USB3 HDD to expand it. Am I wrong in thinking that the MyCloud should now present it as an 8TB storage capacity and therefore look after all access requests as if they were for one drive? It look sa s if I still have a 3/4 full MyCloud with 4TB attached to it. Will external accesses be able to see all videos as one list or do I need to manage it all myself?

When the external USB drive is attached it will be seen and accessed as another Share. One that can be configured through the My Cloud Dashboard. By default that Share is configured for Public Access which means all can see and access the content without having to use a user name/password to access the Share.

If, under Dashboard > Settings > Cloud Access, one sets USB Content Availability = On then the Dashboard home page should indicate a total space of both the My Cloud and the external USB hard drive combined.

Brilliant, Just what I wanted. Thanks