'Freeze management plane on this backend.
Basically puts the control/management plane into a
Read Only state.  We should handle this in the scheduler,
however this is provided to let the driver know in case it
needs/wants to do something specific on the backend.
:param context: security context'

def freeze_host(self, context):

    try:
        self.driver.freeze_backend(context)
    except exception.VolumeDriverException:
        LOG.warning('Error    encountered    on    Cinder    backend    during    freeze    operation,    service    is    frozen,    however    notification    to    driver    has    failed.')
    svc_host = vol_utils.extract_host(self.host, 'backend')
    service = objects.Service.get_by_args(context, svc_host, constants.VOLUME_BINARY)
    service.disabled = True
    service.disabled_reason = 'frozen'
    service.save()
    LOG.info('Set    backend    status    to    frozen    successfully.')
    return True
