Information about --full-block-verification

I’m trying to get more information about about the advanced option --full-block-verification.

According to the online documentation “Use this option to increase verification by checking the hash of blocks read from a volume before patching restored files with the data”.

So, if this option is set to “True”, will Duplicaty only verify the data that is being restored? or, will it verify the data that has been backed-up on the target folder?

I’m very interested in the later option since it will ensure that the backup will have valid data that could be used to restore a system.

Thanks to anyone that can help me understand this feature.

It verifies a final restored file whether or not this option is set, but setting it verifies every patched block.
To me, a per-block verify seems a bit excessive unless one’s trying to debug a whole-file restore error.

Restoring large files explains how blocks are written to the final restored file as necessary to restore it.

There’s no substitute for at least a sample test restore, especially setting no-local-blocks to ensure data came from the backup. A great (though slow) test is Direct restore from backup files to another system.

Verifying backend files checks backup file integrity through actual file download (not just directory listing).
backup-test-samples can ask for a larger sample. backup-test-percentage is available if that’s preferred.

upload-verification-file can be used if your destination is on Windows or a system that has Python to use.
The Duplicati installation utility-scripts folder has DuplicatiVerify.* scripts that can be used for verify.

Thank you so much for your response. Lots of new options that i didn’t know about, specially the “Verifying backend files”

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