Abstract—A Federated Array of Bricks (FAB) is a logical disk system that provides the reliability and performance of enterprise-class disk arrays, at a fraction of the cost and with better scalability. The unit of deployment in FAB is a brick, a small rack-mounted storage appliance built from commodity components including disks, a CPU, NVRAM, and network cards. Bricks federate themselves in a completely decentralized manner to provide users with a set of logical volumes. This paper motivates FAB and introduces our data replication algorithm based on majority-voting. We argue that majority voting is practical for ultra-reliable, high-throughput storage systems like FAB, and present several techniques that improve both the performance and space overhead of our protocol.