Thanks for the reply. So I have to more questions.
Is there any documentary on the used file format so I can write my own file reader for Linux?
To your answer on my 3rd question. Wouldn't that require that all the files copied to the cloud drive would be twice in the temp folder? I only have about 100GB free space on my temp drive and files up to 83GB to upload, having them twice in the temp folder would result in way to less space.