Beyond block I/O: implementing a distributed shared log in hardware

The basic block I/O interface used for interacting with storage devices hasn't changed much in 30 years. With the advent of very fast I/O devices based on solid-state memory, it becomes increasingly attractive to make many devices directly and concurrently available to many clients. However, when multiple clients share media at fine grain, retaining data consistency is problematic: SCSI, IDE, and their descendants don't offer much help. We propose an interface to networked storage that reduces an existing software implementation of a distributed shared log to hardware. Our system achieves both scalable throughput and strong consistency, while obtaining significant benefits in cost and power over the software implementation.