You should see them via tools > multipart uploads.

Yes, thank you! That's what I found.

Do you know if deleting the orphan chunks should work when versioning is activated? Or is S3 going to keep the orphan part as the first "version"?

That should delete everything, versioning shouldn't affect this functionality.

Thank you

Follow up question:

Is it normal that a multipart upload creates multiple (at least 2) temporary "objects" in the destination bucket?

(When checking my utilization on my S3 server, I see that I have a few more active "objects" than expected. Is it caused by multipart uploads or something else?)

The software doesn't create any additional temp files on S3 side, so these are probably created By AWS, they'll be automatically deleted soon.
I can also suggest to check if you have "show deleted versions" option enabled under tools > options > versioning.

As for the objects, what exactly are you referring to?

In fact I'm not using AWS, but Wasabi.

For example, when I check the "utilization" for an empty bucket that has 1 multipart upload pending, it says that there are 2 objects in that bucket:

Unlike AWS S3, Wasabi does not require a Lifecycle Policy to remove incomplete multi-part uploads. Instead, Wasabi will automatically remove them in about 7 days to prevent excessive storage being used.

most likely these are the metadata files for the output file and the uploaded part of the multipart upload. They will be deleted as soon as you delete the unfinished upload.

Thank you both!

Instead, Wasabi will automatically remove them in about 7 days to prevent excessive storage being used.

Strange, because the test upload I interrupted 12 days ago is still not deleted...

Can't open the screenshot for some reason. Can you re-upload it?

@Matt Fresh screenshot from today

I would actually copy that upload ID and contact Wasabi support regarding that. They've been having temporary problems with their services somewhere around the end of July, maybe that's related.