Verify backups

[tombruijn]

See issue backup/backup#601 (comment) for more information

[Ajedi32]

👍 This is a feature that my existing hacky shell script backup solution has that this gem seemingly lacks.

[Ajedi32]

Dup of #7

[tombruijn]

If you've already created something like this before. Please help describe what a good verification process would be. Currently I only see it as a verification of proper uploading by the gem. It would also mean that we have to add "downloaders" to every storage option to download existing backup archives to the server running backup to generate a checksum of the file to compare it.

[Ajedi32]

As I said, my current solution is more of a hack than anything. What I'm currently doing is storing a checksum file next to the backup, then verifying the checksum before restoring. Not sure that really counts as a "verification process". It's more to verify the backup isn't corrupted before restoring.

If your intention is to verify that the backup is actually a valid backup (e.g. it contains all the data you'd expect it to contain), seems to me like that the only real way to do that is to restore the backup somewhere, and check the data yourself. Another, less througough possibility would be to run tests against the backup file somehow. (Maybe check the extracted file for keywords or something. Not really sure.)

[matkoniecz]

My solution is to unpack (covered by #28) and use one of methods from http://stackoverflow.com/questions/4997693/given-two-directory-trees-how-can-i-find-out-which-files-differ (I am using diff --brief -r)

[matkoniecz]

And in case that somebody is interested in reusing my script - compare function is included in https://github.com/matkoniecz/backup-gem-extractor-crutch