How to move data from My Cloud (OS3) to PR4100?

My Cloud OS 5 Personal & Network Attached Storage My Cloud Pro Series
1

I have 3TB+ data on my old My Cloud 4TB. It doesn’t seem to recognize a USB My Passport formatted to ExFAT. Will try NTFS tomorrow.
I’m looking for convenient/reliable way to move data to my new PR4100, ideally I won’t need a computer to do the job.
Please suggest.

2

Ssh into the machine and rsync.

3

Thanks for recommendation.