[Duplicity-talk] Rollup Functionality and Parity?

[Colin Ryan]

In thinking about the uses of duplicity, I'm always concerned about the 
trade off between having to do the occasional large full backup verus 
"infinite incrementals". I see the "infinite incremental" approach as 
the dirty little secret of the hosted storage business where no-one 
seems to acknowledge the sensitivity of this technique to the corruption 
of even a single bit in a single file.

My concern about the latter is should even one incremental in the chain 
become corrupt everything from that point on (I assume) is 
unrecoverable. So I was wondering if there is any technique that could 
be used to "periodically" roll up the incrementals on the remote 
respository side into a full to create an "new single full" which 
contains all the incrementals, but that would allow duplicity to simply 
continue on with incremental backups on the client end. This would 
simply - for what it's worth - reduce the number of files that must be 
100% intact but would allow one to always run duplicity in just 
incremental mode while periodically generating a full.

As a side note has anyone put any thought to using Par2 parity files on 
the tar files that duplicity generates. Yes this would increase the back 
end storage but would allow for recoverability of the file provided data 
corruption was 5-10-20% of the file.

Not sure I've explained my thoughts clearly but...