Re: Have you considered using the "multiple data files" mode of par2?

one *parity file per file that is put* on the backend

On 07.10.2024 15:36, edgar.soldin--- via Duplicity-talk wrote:
> hey Jacob,
>
> i'm sure par2-backend only uses the one parity file tat is put on the backend. what are you hinting at?
>
> sunny regards ..ede
>
> On 07.10.2024 15:22, Jakob Bohm via Duplicity-talk wrote:
>> Dear Duplicity backup format designer,
>>
>> According to the par2 man page (at least on Debian 12), the par2 command
>> has two distinct operating modes.  One mode creates one or more small
>> parity files for a single data file stored on an imperfect medium or
>> service.  The other, processes a group of N data files (such as
>> Duplicity volumes) to produce a few shared parity files.  This second
>> mode is described in the man page under the subheading "CREATING PAR2
>> FILES FOR MULTIPLE DATA FILES" .
>>
>> Switching to the "multiple data files" mode constitutes a change in
>> the backup format and thus needs to be guarded with appropriate
>> compatibility logic in order to restore backups made with either
>> method, even from damaged storage (where par2 files are actually
>> needed) .  To keep a desired robustness level and a manageable temp
>> volume size on the client, it is probably necessary to set an internal
>> limit on the number of volumes for each par2 run .  For example if
>> that limit is 99, the temp volume needs to store about 100 times the
>> volume size even if not pipelining the creation of later volumes in
>> parallel with par2 processing and upload.
>>
>> Enjoy
>>
>> Jakob
>
> _______________________________________________
> Duplicity-talk mailing list
> [email protected]
> https://lists.nongnu.org/mailman/listinfo/duplicity-talk

_______________________________________________
Duplicity-talk mailing list
[email protected]
https://lists.nongnu.org/mailman/listinfo/duplicity-talk