Moving media library from one drive to another

Hi, I have two external drives each with 2TB storage. I am trying to move my media library from an older Seagate to a newer Toshiba. I have reached the half way point but the Toshiba drive is now showing up as full and I have no idea why, all I am doing is scraping over. I have checked to make sure that the files have gone where they should and there are also no hidden files. I have taken two screen shots to give all the drive information.

Thank you in advance for any assistance