Method and system for managing data migration for a storage system

An intermediate device for a storage network, comprising:

• a plurality of communication interfaces, the plurality of communication interfaces including at least a first interface adapted for communication with a first storage device which stores a data set, a second interface adapted for communication with a second storage device, and a third interface adapted for communication with a client processor;
• data transfer for resources coupled to the plurality of interfaces which transfer data access requests identifying the data set from the third interface to the first interface;
• a logic engine, coupled to the first and second interfaces, which in response to a control signal, manages transfer of the data set through the first interface from the first storage device and through the second interface to the second storage device;
• logic to assign a priority to the transfer in relation to data access requests from the client processor, and to manage the transfer in response to the priority;
• and,
• data structures which store status information concerning progress of the transfer, including a parameter indicating an extent of the data set which already copied to the second storage device.