Concrete example of what I meant:
- Copy the files to an external hard disk
- Plug-in the hard disk into the server
- Install the client on the backup server and select the hard disk
- Backup the files to the server (locally)
- Backup the server with the 2 TB with client side hashes enabled. UrBackup will only backup files it does not already have
Works only with file backups, though. Maybe you meant image backups?