Building Flexible, Fault-Tolerant Flash-based Storage Systems

Adding flash memory to the storage hierarchy has recently gained a great deal of attention in both industry and academia. Decreasing cost, low power utilization and improved performance has sparked this interest. Flash reliability is a weakness that must be overcome in order for the storage industry to fully adopt flash for persistent storage in mission-critical systems such as high-end storage controllers and low-power storage systems. We consider the unique reliability properties of NAND flash and present a high-level architecture for a reliable NAND flash memory storage system. The architecture manages erasure-coded stripes to increase reliability and operational lifetime of a flash memory-based storage system, while providing excellent write performance. Our analysis details the tradeoffs such a system can make, enabling the construction of highly reliable flash-based storage systems.