[jaw]

I'm mostly trying to address cases where there is no original file that I fully trust. If I'm exporting my data from some web app/service, I can't get a hash of the data as it is in the actual source of truth on their servers, and there's multiple points at which an error could be introduced before the completed export file lands on my machine.

It's a good point that hashing is a better method when you have access to the original files.

[close04]

> and there's multiple points at which an error could be introduced before the completed export file lands on my machine

Aren't all bets off at this point? I mean validating the backup seems skipping steps if you are not validating the source. Scrolling through thumbnails is better than nothing, sure. But it's really prone to false negatives. Corrupted images can look good in a thumbnail and your eyes might just miss even glaring corruption because you just scrolled too fast. If it's not an image file it gets more challenging.

You seem to have one of those corner cases where basically no automated method can solve your problem but the volume of data is just low enough to alleviate the issues with a bit of manual intervention.

[jaw]

> Scrolling through thumbnails is better than nothing, sure.

"Better than nothing" is pretty much what I'm going for here. Almost all my personal data stored in cloud services falls into this "corner case": I only have indirect access to the source, it's important enough to me that I want to do some level of checking, but it's not important enough to spend the huge amounts of time it would take to inspect every individual datum.