Upload / asynchronity settings unclear

I found 3 different settings

–asynchronous-concurrent-upload-limit
–asynchronous-upload-limit
–synchronous-upload

what does each of it?

I have set --synchronous-upload to true but I still have 4 parallel uploads.
Then I have set --asynchronous-upload-limit to 1 but still I have 4 parallel uploads.
If I set --asynchronous-concurrent-upload-limit to 1 then I get 1 upload

I think (but not really sure) that --asynchronous-upload-limit is the number of files that are created locally ADDITIONAL to the ones that are uploaded. Is that correct?

But what exactly does --synchronous-upload?

Are you not in the GUI, seeing help text? Let me copy it from Duplicati.CommandLine.exe help text:

  --asynchronous-concurrent-upload-limit (Integer): The number of concurrent
    uploads allowed
    When performing asynchronous uploads, the maximum number of concurrent
    uploads allowed. Set to zero to disable the limit.
    * default value: 4

Above is somewhat new, and not yet in the manual Advanced options yet. The two below are there.

  --asynchronous-upload-limit (Integer): The number of volumes to create ahead
    of time
    When performing asynchronous uploads, Duplicati will create volumes that
    can be uploaded. To prevent Duplicati from generating too many volumes,
    this option limits the number of pending uploads. Set to zero to disable
    the limit
    * default value: 4
  --synchronous-upload (Boolean): Upload files synchronously
    Duplicati will upload files while scanning the disk and producing volumes,
    which usually makes the backup faster. Use this flag to turn the behavior
    off, so that Duplicati will wait for each volume to complete.
    * default value: false
1 Like

Good point. I read the documentation here

and there was no concurrency option explained (in found this option with Google somewhere in the forum).

Thank you. That makes it clear!

One for the scanning process synchron/asynchron
One for the number of parallel uploads
One for the number of additional upload files generated