Does upload to Backblaze B2 storage cause automatic download?

I have a Nextcloud 19 docker installation on a VPS with Backblaze B2 configured as primary storage. Server side encryption is enabled. I uploaded some files (around 22GB) using the Nextcloud desktop client (version 3.0.2) on Windows 10. When I checked the Backblaze data usage details, it showed an equivalent increase in download. To confirm that this is not an anomaly I checked the data transfer on my VPS provider and it too showed an increase in incoming traffic for the similar amount of data (excluding the amount of data from my desktop to VPS).

What is causing the download when the files were only uploaded? Is this expected?


I remember here a discussion about AWS S3 transfer cost. Some month ago. But I didn’t follow it.
So if you don’t get an answer here, you may use the search function.

Thanks for the pointer. I looked in the forum and found the following that is the closest to the problem I have.

No solution there as well. Is there a log file where I could check the S3 API calls being made or the file operations?

This is an old thread, which I found when seaching explanation for a similar situation.

Last weekend I created backblaze account, configured it as my personal external storage in nextcloud (20.0.9) and then uploaded my media (mp3) collection to blackblaze. ~9gigs on weekend and almost a gig yesterday. The upload was done by rcopy. After the upload I did occ files:scan for the backblaze path. Now from the backblaze reports I see there’s been download of 5 gigabytes. I have not downloaded any of the files. I have accessed the blackblaze files (bucket) via nextcloud though. 5 gigs is a lot of download if it’s all just nextcloud checking the contents of the bucket. Or could it be the occ: files:scan?

Either way, it’s quite excessive.
Anyone else experiences similar issues?
I need to monitor how the downloaded data figures go. This behaviour may render the idea of using blackblaze as external storage to useless.