Thanks, I'll take a look at both.
Basically, I map a folder structure to a drive letter, and then back up from there to an 8TB drive I temporarily connect via USB. I put only the important stuff in the folder structure. There is 16TB of storage on the NAS, but I have a ton of TV on there, which I put in a different folder structure.
I then hide that disc in case we ever have someone come in and take everything. At one time, I had two 8TB USB drives, and I took one to work. Unfortunately, I dropped the one at work and killed it.
What Good Sync was doing was a direct copy of files, so I had the entire file structure. It kept a "database" of sorts where it could see what had been modified, so each time I ran it, it would only copy the files that were modified.
For One Drive, I'd like to be able to do something similar: copy everything from it to the 8TB drive.