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.
Single-parity RAID is under attack. Caching is the hottest trend in storage. The end of the high-performance disk drive is imminent. What happened? Increasing areal bit density has caused disk capacity to grow much faster than disk performance. A presentation at Storage Networking World by Ronald Bianchini of Avere exposed the mathematics of this phenomenon.