I have set up a volume in unity catalog in the format catalog/schema/volume, and granted all permissions to all users on the catalog, schema and volume.
From the notebook I can see the /Volumes directory in the root of the file system but am unable to read or list files within it.
import os
import stat
stat.filemode(os.stat("/Volumes").st_mode)
# 'drwxrwxrwx
stat.filemode(os.stat("/Volumes/catalog").st_mode)
# PermissionErro: [Errno 1] Operation not permitted: '/Volumes/catalog'