I don’t know what the right thing to call it is… incremental? Differential? I currently have it set to: “Keep All Backups” in step 5 of the configuration. From the description of that option I thought it was the right thing but my storage space at the destination is climbing like a rocket ship! Maybe I’m not saying this right - I only want the deltas (the changes since last backup) to be added to cloud storage not a sum of full backups Because of the the way the data is output (the backup format) I can’t really tell what I’m ending up with at the destination - just that I’m watching the space used climb by the gigabytes daily.
Duplicati already works this way. It only stores the differences between backups. (In fact there’s no way to turn that feature off - it is core to its backup engine.)
To reduce storage on the back end, you’ll have to reduce retention.
I was kind of wondering if that should be changed. It might even be an inadvertent leftover from early days when a deletion wasn’t implied. You could go digging in the history to see what pieces were done when…