Wish there was an easy answer. I believe the root of your question was about AV/DVR vs Desktop drive. In practical terms I would say they are equivalent as far as potential for data corruption. As for consequences... corrupt backup data doesn't hurt until you need it for recovery. The likelihood of corrupt data on disk can be minimized by doing a "full backup" (rather than all incrementals) 4-12 times a year. This will refresh the data on disk and confirm (by lack of unrecoverable disk error) that the drive is functional. If you did incrementals only (obviously after first full backup) then confidence declines with time. I understand why there is a desire to use HDD as a backup medium - high capacity, fairly reliable, and cheap. It is better than no backup at all and good enough for most people. As I'm constantly reminded on dbstalk, I'm not most people. It's not good enough for me. I guess that is because I've had a career of seeing things go bad for no good reason when it could have been prevented easily with trivial effort and expense. In most cases the small incremental cost is worth it to me.