How can I be sure my data is being backed up?

Episode 1026 (1:17:03)

Dave from Crystal Lake, IL

Dave is using Western Digital's backup software with his WD External drive. How can he be sure he's backing up all his data? Leo says that he can't since WD uses a protocol that backs up all files into one big master file (or what Leo calls a big ball of stuff). Leo recommends more of a sync based backup option, like SyncToy or ChronoSync, which will backup all data and then sync any files that get changed.