Dear All. I apologize for my double post. I just realize after I write the second one. The first one is posted before I joint the list, it's http://lists.openstack.org/pipermail/openstack-discuss/2018-December/000745.... And the second one is : http://lists.openstack.org/pipermail/openstack-discuss/2018-December/000760.... Sincerely -bino-