A Realistic Distributed Storage System That Minimizes Data Storage and Repair Bandwidth

In a realistic distributed storage environment, like the ones used in companies dedicated to the task of storing information over a network, storage nodes are usually placed in racks, a metallic support designed to accommodate electronic equipment. It is known that the communication (bandwidth) cost between nodes which are in the same rack is much lower than between nodes which are in different racks. In this paper, a new mathematical model for a distributed storage environment where the storage nodes are placed in two racks is presented and analyzed.