'Stop managing a volume.
This action is very much like a delete, except that a different
method (unmanage) is called on the Cinder driver.  This has the effect
of removing the volume from Cinder management without actually
removing the backend storage object associated with it.
There are no required parameters.
A Not Found error is returned if the specified volume does not exist.
A Bad Request error is returned if the specified volume is still
attached to an instance.'

@wsgi.response(http_client.ACCEPTED)
@wsgi.action('os-unmanage')
def unmanage(self, req, id, body):

    context = req.environ['cinder.context']
    authorize(context)
    LOG.info('Unmanage    volume    with    id:    %s', id)
    vol = self.volume_api.get(context, id)
    self.volume_api.delete(context, vol, unmanage_only=True)
    return webob.Response(status_int=http_client.ACCEPTED)
