Time Capsule external USB drive - as second Time Machine Drive? I have a 3TB Time Capsule ac. Which is used for Time Machine wirelessly.
I would like to connect an external USB Hard Drive to the Time Capsule and use it as an extension to TimeMachine to backup more than 3TB.

What problems if any would I encounter? And how will this work?
Can I have the external drive connected to the Time Capsule work with Time Machine as well?
Connecting an external drive won't extend the built-in storage per se; rather, you'll be able to back up to either the internal disk, or the disk connected via USB. Of course, you can switch back and forth, but they won't be combined into one volume.