File system and storage array design challenges for flash memory

Over the few decades the characteristics of the magnetic disk based persistent primary storage system have remained essentially unchanged. Seek, read and write are the primitive operations that can be performed against these devices. These three operations have endured because the devices within storage subsystems have not fundamentally changed since the invention of magnetic disks. In many cases, the file systems for the existing storage arrays are custom and proprietary and tuned for the characteristics of magnetic disk. As the cost of flash memory continues to decrease, enterprises are attempting to deploy flash in primary network attached storage systems such as storage arrays. Flash memory poses unique characteristics, which requires sophisticated data structures and algorithms to exploit the performance benefits. When flash memory is used in primary storage arrays, the file systems face lot of design challenges for the optimal flash performance and device endurance. Replace the new flash arrays with existing enterprise disk based storage arrays that provide data management and protection features is a challenging task. We discussed various challenges in file system and the storage arrays for integrating flash memory arrays in the primary storage. Also we discussed the previously proposed solutions to overcome the discussed problems.