Re: [rdiff-backup-users] snap-shots every 10 diffs...

[Andrew Ferguson]

On Mar 23, 2009, at 3:51 PM, address@hidden wrote:
> So, I really simply don't know what to believe. I don't have a case
> first-hand I can examine to see for myself. (And the cases where
> someone has gone and looked, there are NO snapshots, only rdiffs.)
>
> That's exactly why I asked this question again.
>
> It sounds like a myth that's widely believed, but no-one is certain
> which way is the way it actually happens...


Hi Greg,

Sorry for the confusion. I know I am the source of some of it, because  
I did not realize until recently that there are two different behaviors.

For the *metadata* files, the snapshots occur exactly as Simon just  
described.  The metadata files are the ones in the top level of rdiff- 
backup-data, and have names like: mirror_metadata.* ,  
extended_attributes.* , etc.

For regular files, only reverse deltas are saved. You are correct that  
this introduces fragility in teh system. The tradeoff is that if you  
want snapshots (like for the metadata), then your repository will grow  
much, much faster, so no snapshots are kept.


hope this clears things up,
Andrew