Changing missing blobs, but nothing changes

Getting Help
1

I am syncing a repo with Syncthing. When I try to check it on the machine that it synced to, I get informed that there is a blob missing. I was assuming that the sync has not finished. However, what is weird is that every time I check, another blob is reported, and that happens even when Syncthing is paused. Like this:

$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:01] 100.00%  196 / 196 index files loaded
scanning...
blob <data/9256ebd7> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:01] 100.00%  196 / 196 index files loaded
scanning...
blob <data/e1e1a7c1> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:02] 100.00%  196 / 196 index files loaded
scanning...
blob <data/21012e67> not found
$ restic version
restic 0.18.1 compiled with go1.25.6 X:nodwarf5 on linux/amd64

Why is it reporting a new missing blob even if nothing has changed in the repo? (at least that’s my assumption – Synchting is paused)

I am syncing other repos with Syncthing too, and there the issue does not exist.

2

Most likely some part of this operation is multi-threaded, and if any thread runs into an error, the whole process stops there, so you might see many different missing blobs based on which thread runs into that problem first.

3

Thanks for the explanation! So, after running it a few times, I expect it to report an already reported missing blob again. And indeed that is what happens (455d37e0 below):

$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/bbf50b47> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/21012e67> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/36233480> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/a77c5717> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/455d37e0> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/733db673> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/1eaa4d61> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/b517547b> not found
$ restic --verbose stats --mode raw-data
repository eb2726b0 opened (version 2, compression level auto)
[0:00] 100.00%  197 / 197 index files loaded
scanning...
blob <data/455d37e0> not found

It’s just so weird that syncing of this Restic backup never finishes. All my other files, including those in several Restic repos, sync fine with Syncthing.

4

Does this restic stats command finish on the machine you are syncing from?

5

Yes, it does. I figured it’s a weird syncing issue with Syncthing.

6

It probably is a Syncthing issue, yes.

As a side note, syncing your repository is probably a bad idea if that is part of your backup strategy. If a malicious process deletes or encrypts (think ransomware) the repo contents on the server, it will dutifully sync the changes to the other machine, and your backups will be lost.

A nightly rclone copy --immutable that is executed on the receiving machine would be a better idea.

1 Like
7

Thanks for pointing that out. I’m aware of that. These backups get backed up by Restic append-only to another system, a Hetzner storage box, several times per day. I only use Syncthing so that I also have a copy of the backups locally on my mobile computer, from which I do regular backups to an external disk.

If ransomware would destroy the backup, I could restore it from the Hetzner storage box, or from an external disk.

(Restic backing up Restic, yes. But these backups are fairly small, basically configurations of my machines.)