This command will fail, if there would be a config.yaml. So, you need to rename or delete it first. This is done to protect from second (unintended) run of the setup, because it’s very important for protection.
So you would need to do it only when you are sure what are you doing.
This command also will create all needed/missed folders structure and storage-dir-verification file containing your NodeID in binary form.
This file is used to check if the current NodeID matches the stored in file to protect from running with a wrong identity. It’s also verified if it ever exist, if not the node will fail to protect from disqualification because of missed disk in mountpoint for example.
If there would not be a needed folder structure the node will crash too to protect from missed disk in mountpoint again.
The file is checked also on write and node will fail, if it’s not writeable (in case of read-only fs or wrong permissions)