[Borgbackup] delete and prune use consume gigs of data

[Jim Popovitch]

On Thu, 2023-05-18 at 18:39 +0200, Thomas Waldmann wrote:
> 
> On 13.05.23 21:14, Jim Popovitch via Borgbackup wrote:
> > On Sat, 2023-05-13 at 14:25 -0400, Jim Popovitch via Borgbackup wrote:
> > > Why does delete and prune seem to consume as much (or more) data as a
> > > create does, especially when the prune is done from a different location
> > > than where the create is initiated?  I tried to delete some old server
> > > backups, using a session+key on my laptop, and the stats say my laptop
> > > xfer'ed in and out 1Mbs for 3 hours (that's a lot of transferred data
> > > for a delete).
> > > 
> > 
> > Further insight reveals a new 1.5G .cache/borg folder.
> 
> If that folder wasn't there before, borg had to do a re-sync of the 
> chunks index. This is needed for prune/delete operations because it 
> contains the refcounts for each chunk.
> 
> Once the resync is done (and while it stays in sync), it will work 
> quicker and with much less traffic.

Thanks for the explanation, indeed that folder was not there before. The
backups are done from servers directly to remote storage, and I was
doing the pruning from my laptop.  Now that the servers have produced
more backups (to the remote storage), should I expect to see
~/.cache/borg grow larger on my laptop the next time I prune?

-Jim P.