I have two of the exact same 2TB external HDDs. I copied a bunch of information to one of them and then copied everything from the first to the second HDD and now their sitting at different amounts of free space. The copy job completed without error and there are no obvious large hidden files lying around.
First question is: how can this happen? I used robocopy so I know I brought over all hidden files and everything
Second question is: is there anything I can use to make sure both HDDs have exactly the same information on them?