[Borgbackup] Recovery from missing segments

[David Gasaway]

On Tue, Jul 17, 2018 at 2:09 PM, Thomas Waldmann <tw at waldmann-edv.de> wrote:

> Did you use --progress? Your borg version (on client, on server)?

Sorry!  I missed that one.

>>> Hypothetical mode would simply
>>> check the filesystem for the expected segment files, and if not found,
>>> replace the associated chunks in the index with zero chunks so the
>>> chunks/segments get recreated at the next backup (assuming source data
>>> is still present).
>>
>> On second thought, I may also need it to do something like check the
>> expected length of segment files in case a new chunk was added to an
>> existing segment, but the segment was "rolled back".  The more I think
>> about this though, what I'd probably want is a way to invalidate any
>> chunk created after a certain date/time.  Not sure if this is
>> possible.
>
> If borg check --repair determines that a chunk is not there any more, it
> puts a same-length replacement chunk there, but it still remembers the
> healthy chunkid (content hash). See my other post from today about how
> it can later use that for healing.

Yes, but it only does that with a repository check that reads the
content of all the segment files.  I'm still hypothesizing out loud a
new mode that would not.

Thanks.

-- 
-:-:- David K. Gasaway
-:-:- Email: dave at gasaway.org