There are a few config options available. Can we verify if one of them would change the behavior already?
filestore.write-buffer-size: 3MB
pieces.write-prealloc-size: 3MB
I never checked what these options will do. I just noticed that 2. something MB is the biggest piece on Disk. Lets allocate 3MB everywhere. I have the RAM for it so even if these otions are useless I just set them on my node.