Home > Storage > PowerMax and VMAX > Data Protection > Dell PowerMax and VMAX All Flash: SRDF/Metro Overview and Best Practices > Configuration overview
The following sections describe the states through which a device pair in an SRDF/Metro configuration may transition during the configuration’s life cycle and the external events and user actions which trigger these transitions.
The life cycle of an SRDF/Metro configuration typically begins and ends with an empty SRDF group and a set of non-SRDF devices. Since SRDF/Metro does not currently support concurrent or cascaded SRDF devices unless these devices are part of a supported SRDF/A configuration (see Features and functionality by service release for additional information), devices that will constitute the SRDF device pairs typically begin as non-SRDF devices. These devices may then return to a non-SRDF state following a deletepair operation, terminating the SRDF/Metro configuration.