Currently, CU have a requirement to remove an existing QoS policy applied to a specific volume and also need to know the capabilities of retype (Ondemand & never) the volume to a new volume type of same backend and different backend.

CU looking Cinder API call to remove QoS.

Process
> Cinder volume created. (Veritas API call ) -> Cinder volume snapshot taken ( Veritas API call )> Cinder temporary volume from snapshot created ( Veritas API call ) -> Convert to QCOW2 from temporary volume ( Veritas API Call ) -> QCOW2 mount to compute where VM running ( Ushare also mounted to compute ) ( Vertias API Call ) -> Data from QCOW2 mounted to UShare ( Veritas API call ) -> Umount QCOW2 and Delete temporary volume.

For full API details, please refer:
https://docs.openstack.org/api-ref/block-storage/v3/ : Search for "create volume" API.

POST: /v3/{project_id}/volumes, Create a volume

Request payload:
{
  "volume":

{     "snapshot_id": "<snapshot-uuid>",     "name": "<new-volume-name>",     "size": <size-in-gb>,     "volume_type": "<volume-type-name-or-id>"   }

}