Dynamic multi-pathing (DMP) is a type of communication path control software application. Path control is an approach to optimizing configuration and routing management for storage networks; DMP is used to automate these processes for storage network data backup and restoration. DMP was designed in response to the complex needs of storage networks as compared to ordinary data networks: Connection failures in data networks generally just mean that the connection must be retried; in storage networks, however, a failure is more likely to cause a system crash . The margin for error is smaller for storage networks as well: whereas error recovery within minutes is acceptable for properly functioning data networks, for storage networks it should be within seconds - and preferably milliseconds.
To address these differences, storage networks should be designed to enable the greatest possible configuration flexibility and system availability. However, added flexibility also increases the possibility of connection failures: where a storage system at one time might have consisted of a single storage device connected to a single host by a single cable, a storage system today typically consists of multiple diverse devices in an interconnected network topology . DMP software applications automatically reroute data through alternate paths in the event of a connection failure.