The Four Horsemen of storage system performance cannot be denied, but they do offer a clear path forward. Storage systems must improve in many different areas, from spindles and drives to caching and I/O bottlenecks. But above all else, storage systems must become smarter in order to become faster, and this requires greater insight into the true nature of the data stream being stored. All storage performance developments, from the laptop to the enterprise, boiled down to adaptations to the demands of the Four Horsemen.
It is tempting to think of storage as a game of hard disk drives, and consider only The Rule of Spindles. But RAM cache can compensate for the mechanical limitations of hard disk drives, and Moore’s Law continues to allow for ever-greater RAM-based storage, including cache, DRAM, and flash. But storage does not exist in a vacuum. All that data must go somewhere, and this is the job of the I/O channel.