'Removes the export configuration for the given volume.
:param volume:  volume object provided by the Manager'

@utils.synchronized('vmem-export')
def _unexport_lun(self, volume, connector=None):

    v = self.common.vmem_mg
    LOG.info('Unexporting    lun    %s.', volume['id'])
    try:
        self.common._send_cmd(v.lun.unassign_client_lun, 'Unassign    SAN    client    successfully', volume['id'], connector['host'], True)
    except exception.ViolinBackendErr:
        LOG.exception('Backend    returned    err    for    lun    export.')
        raise
    except Exception:
        LOG.exception('LUN    unexport    failed!')
        raise
