Since pieceinfo.db is empty now, the node cannot recognize the used space and check only free space, which is less than required minimum of 500GB.
You can temporary disable this check by reducing value for storage2.monitor.minimum-disk-space option in the config.yaml file or specify it as a command line option after the image name in your docker run command, i.e. --storage2.monitor.minimum-disk-space=400GB
It should start and run a filewalker, it will fill up the database and then storagenode should recognize its used space.