---
features:
  - |
    Added a new default volume type ``__DEFAULT__`` which
    will be used when

    - A new volume is created without a type
    - The `default_volume_type` option is unset in cinder.conf

    Then the volume will be assigned the ``__DEFAULT__`` type.
upgrade:
  - |
    The db migration script will create a volume type named
    ``__DEFAULT__``
    The online migration will migrate all existing untyped
    volumes, snapshots to the ``__DEFAULT__`` type.
    An invalid/non-existent type specified with `default_volume_type`
    option in cinder.conf will result in VolumeTypeNotFoundByName exception.