--- other: - | Nova will now internally use a new flow for new volume attachments when: * All *nova-compute* services are upgraded * The *block-storage* 3.44 API microversion is available This change should be transparent to end users and does not affect existing volume attachments. Also, this does not affect how new volumes are created and attached during boot-from-volume when the ``block_device_mapping_v2.source_type`` is ``blank``, ``image`` or ``snapshot`` and the ``block_device_mapping_v2.destination_type`` is ``volume``. The motivation behind these changes are: * Track volume attachment state in the block storage service rather than the compute service (separation of duties, simplicity, etc) * Removal of technical debt from the compute service long-term * Enable a foundation on which to build support for multi-attach volumes More details can be found in the spec: https://specs.openstack.org/openstack/nova-specs/specs/queens/approved/cinder-new-attach-apis.html