So, I currently use Ubuntu mostly for backing up data on broken computers. Recently, though, I wanted to back up a system completely. The harddrive had 300GB of storage. I mounted the main partition on the drive (NTFS) and copied all the files to an external drive (NTFS). As I waited for it to calculate how much it would be copying, the size it was reporting continued increasing, even beyond 300GB. (I never let it finish - I just backed up what was necessary.)
I'm now backing up yet another harddrive (NTFS again) - a 500GB one to another external drive (NTFS). I was not able to mount the drive; so, this time I'm generating an image of it via the terminal "cat" command. I now found that the file it's generating has already exceeded 650GB and is still going. (Edit: it's now just past 850GB)
What am I missing here? How can a drive have more information on it than it's physical size can hold? Or perhaps, what am I copying recursively? It might make some sense for the mounted HDD, but how could it possibly be more for the one I haven't even mounted? Or am I using the "cat" command wrong? sudo cat /dev/sdc > "/media/ExternalDriveName/hdd-backup.img"