A free TB size cloud backup? I couldn't find much on what/when is the part where someone is going to pay for it. Backups ain't the issue here though. It's figuring out when either the backup or my local copy integrity fails. I'm mostly interested in the local copy integrity though.

I already have a solution in place I developed years ago but it's more complicated, fragile and too much hassle. I like the specified solution, even though it has some limitations it seems good on paper. I'm just wondering whether I have missed any obvious flaws.