Restic stats difference between 0.13.1 vs 0.14.0

Getting Help
1

Hello,

I upgraded one of my remote ssh repos to repo version 2 yesterday using the instructions from the homepage. Everything went smoth and a subsequent restic check run did not reveal any problems.

What I noticed though is that the restic stat produced vastly different results before and after the migration. Here is the ouput of the two restic stat runs:

Before migration using restic 0.13.1

repository db047304 opened successfully, password is correct
scanning...
Stats in restore-size mode:
Snapshots processed:   31
   Total File Count:   511711
         Total Size:   29.894 GiB

After migration using restic 0.14.0

repository db047304 opened (repository version 2) successfully, password is correct
scanning...
Stats in restore-size mode:
Snapshots processed:   31
   Total File Count:   511711
         Total Size:   376.665 GiB

The total size in the second restic stat ouput differs substantially from the former run by more than an order of magnitude.

Should I be worried about this discrepancy? Or could this just be a bug in the way either of the commands calculates the total?

Interstingly I could not reproduce this with a second local repo on a usb drive that is directly attached. The total size output of restic stats was exactly the same before and after the migration.

Cheers

2

This looks to me like it might be due to a bug that was fixed in Fix restore size calculation for multiple snapshots by MichaelEischer · Pull Request #3740 · restic/restic · GitHub

So the second restic stat run (the one using restic v0.14.0) produces the correct “Total Size” figure.

3

Thank you @shd2h for your reply. I found the same bug you mentioned in the meantime by browsing GitHub issues. It would certainly explain my observation.

If restic check returns with a positive result, I should be on the safe side with my backup repo, is that correct?

4

That depends on what exactly you wanted to check. Quoting the docs, there are two types of checks restic can run on the repository:

  • Structural consistency and integrity, e.g. snapshots, trees and pack files (default)
  • Integrity of the actual data that you backed up (enabled with flags, see below)

If you want to run the second check, you’ll need to run restic check --read-data. This isn’t the default behaviour, because it’s slower and it involves retrieving every pack file from the repository.
Full details here: Working with repositories — restic 0.14.0 documentation

Speaking specifically to your situation, assuming you just wanted to make sure that the conversion completed successfully, I would say that a normal check passing is a good indication that all is well. For maximum thoroughness that all of your data is intact though, using --read-data would seem to make sense.

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