Reverting direction of copy

Support
#1

Hi all,

I use Duplicacy-Web with Google Cloud Drive as my main backup storage and Backblaze B2 as a copy storage. However GCD really is a bit slow on retrieval, so I was thinking, of setting this up a bit differently. While I know that one can (somehow) configure Cloudflare to use with B2 to avoid B2’s egress fees, getting this to work would take some time (even if I knew what I was doing).

Since the backup is small in size (currently ca. 40GB), I created a 3rd storage locally on my NAS and copied the GCD backup to that storage.

So right now the setup is::

Data -> backup -> GCD
                      -> copy -> B2
                      -> copy -> Local NAS

What I want to change this to is:

Data -> backup -> Local NAS
                      -> copy -> B2
                      -> copy -> GCD

Since all three storages have the same versions, same amount of chunks, same pruning schedule, I would assume that it is safe to simply make that change.

But I’d like to get some feedback, whether this is indeed safe or if I have overlooked something.

Thanks in advance for any help on the matter,
Bernhard

#2

This should be fine.

Though do bare in mind - even though you may have the same prune schedule, if you don’t run them on the same day as each other, you might end up with different revision numbers between the storages, and therefore holes that may need to be re-copied back, if they don’t match up exactly.

You could use -dry-run to see what would be copied if you were to try the other direction.

#3

Thanks so much for the feedback. Unfortunately there is no “-dry-run” option for copy for some strange reason. :confused:

"-dry-run" option for copy command missing?
#4

Hmm, good spot! That is a bit surprising…

If you do a list -all on both storages and manually compare the revision numbers, that should give you an indication if they’re in sync.