[Borgbackup] Data integrity error: Invalid segment entry size 0 - too small

[Thomas Waldmann]

> Starting repository check
> Data integrity error: Invalid segment entry size 0 - too small [segment
> 253305, offset 2331522]                                           
> attempting to recover /mnt/synology/Qubes-personal/data/25/253305

Here, it likely discarded one object ("segment entry") from the repo.

Because you checked with --repository-only, it did not do an archives
check / consistency fix, so it might well be the case that some archive
is still pointing to the object it just deleted (because it was corrupt)
and this is likely why you get:

> Pruning archive: personal-2018-07-20_T15:00          Fri, 2018-07-20
> 15:00:16
> [7f3e8e3477faf30de92fefec41baf2243045c085b8a957b9d764a63202ad16a8] (955/982)
> Object with key
> aaffc27b2efdca19941a533c2d62644e9d1bfb9867f030378eca7df6c9e5df1f not
> found in repository /mnt/synology/Qubes-personal.

So, what you can do is a full borg check --repair.

If you are still confident in the repo being ok now and no hardware
corrupting anything, you could also try with --archives-only to only do
what you did not already do in the first check/repair run (and not
repeat the repository part).

It will then try to make the archives consistent again. If a content
data chunk object is missing, it will replace it by an all-zero
replacement chunk of same length.

After that, do backup(s) of your data (if you are lucky, the lost
content chunk will still be produced by borg create).

Then do another borg check --repair. If you are lucky, it can heal the
archives, replacing the all-zero chunk by the correct chunk.

TODO: do we have this ^^^^ in the docs / faq?


-- 

GPG ID: 9F88FB52FAF7B393
GPG FP: 6D5B EF9A DD20 7580 5747 B70F 9F88 FB52 FAF7 B393