[csdvrx]

I have versioned backups for a few months. Most people don't and can't (it requires a lot of storage)

Even if they have them, the diffing needs to be done.

Given the past problems with ZFS, I think I'll write a summarizer, that creates a database of metadata for each backup: it will be small to keep around, and may be use more easily to determine which backup contains the uncorrupted file.

[uselpa]

I use borgbackup so the storage requirements are fairly low if the data does not change too much (which is my case). Also diffs are just a « borg diff » away.