In a system and method for a storage area network (SAN), a first controller receives a write request for a SAN and communicates with a first nested storage array module (NSAM), the first NSAM manages storage of data onto a shelf and presents the shelf as a logical unit, a buffer stores a portion of a write request from the first controller and aggregates data from the write request for the shelf, from a shelf with a second NSAM, the second NSAM provides a portion of data from the buffer to a third NSAM, the third NSAM manages storage of the portion of data from the buffer to a physical storage unit, and a second controller coupled to the first controller handles requests for the SAN in response to a failure of the first controller.