Help me understand the output of --progress and --stats

[jmdesprez]

Have you checked borgbackup docs, FAQ, and open Github issues?

Yes

Is this a BUG / ISSUE report or a QUESTION?

QUESTION

Hello,
I've some difficulties to understand what the --progress option output.

From the documentation : The --progress option shows (from left to right) Original, Compressed and Deduplicated (O, C and D, respectively), then the Number of files (N) processed so far, followed by the currently processed path.

But the documentation also indicate : Compression is applied after deduplication (Internals documentations about compression).

Here is an example of what I see during a borg create --progress .... : 28.53 GB O 20.76 GB C 7.87 GB D
As the compression is applied after the deduplication, how the Compressed size can be larger than the Deduplicated size?

Same question for the --stats as the summary display something like this :

                       Original size      Compressed size    Deduplicated size
This archive:               33.00 GB             23.82 GB              9.21 GB

The compressed size is also larger than the deduplicated size.

This sentence from the documentation : "“This Archive” deduplicated size there is most interesting as that is how much your repository will grow" make me think that "Deduplicated size" is the size of deduplicated chunk after compression, is it correct?

Can someone help me understand these outputs?

Thanks :)

[infectormp]

Original size = size of data that was backup by borg. i.e. size of source directory
Compressed size = size of backup after compression.
Deduplicated size = size of backup after deduplication. This is size of your repository on a file system.

[jmdesprez]

Hello,

Thanks to your comment and some test I've done using different --compression I now understand more clearly :)

Thanks a lot !

[ThomasWaldmann]

The C)ompressed value is a somehow synthetic value.

Borg first deduplicates and only compresses if the data is not duplicate.

So what it shows after C is the size ALL input data in the backup set would have IF it were just compressed, but not deduplicated.