Re: [rdiff-backup-users] atomic increment files?

[Andrew Ferguson]

On Mar 9, 2009, at 10:58 PM, Marcel (Felix) Giannelia wrote:

> > Unfortunately, --remove-older-than is more complicated than that.  
> > It also has to transform the last remaining increment into  
> > snapshots, as opposed to reverse-deltas. That would be a nasty  
> > operation if all of the increments were in archives. (remember,  
> > rdiff-backup mostly stores the increments as reverse-deltas.)
> I'm missing something important here -- why does the last increment  
> have to become a snapshot? Isn't the restore procedure just "start  
> with the mirror file, then apply patch after patch until we get to  
> the right file version"? Also, wouldn't turning all of the last  
> remaining increment into snapshots double the size of the mirror  
> (since you'd have the "now" mirror, and the "farthest back in time  
> snapshot" in the rdiff-backup-data dir)?


Whoops, you're right, I was thinking backwards.

But, yeah, rdiff-backup stores a snapshot file after every ~10  
increments, so that it doesn't have to apply more than 10 increments  
during the restore. Also, that is helpful for recovery if an increment  
gets corrupted.

Plus, I do want to see a merge increments operation one day. I feel  
like keeping the increments as distinct files makes that easier.


Andrew