gnocchi/common/storage/file.yml

parameters:
  _param:
    gnocchi_storage_file_basepath: /var/lib/gnocchi
    gnocchi_storage_driver: file
  gnocchi:
    common:
      storage:
        driver: ${_param:gnocchi_storage_driver}
        file_basepath: ${_param:gnocchi_storage_file_basepath}