I have a 5TB external hard drive which I use to store media files on like music and videos. I don't have a large enough second harddrive to duplicate a direct complete backup, but I have a 3TB and a 2TB. I was wondering if I could use software to split the files between the two backup drives. I would like to set up a preference to pre-determine where I want the files to go (and only have to set this up once), so that way every couple of months I could plug in the backup drives and basically hit "start". PS: I would a prefer software solution rather as opposed to manually replacing the folders because I would like to only replace files that have changed or have been deleted (in which case it would not keep a backup) and create an exact copy. This would save time in the transfer and not have to re-copy the same files each time.