An open-system framework for flash-memory storage system

In recent years, MLC flash memory, which stores 2 or more bits per cell, has gradually replaced SLC flash memory due to its lower cost and higher density. However, MLC flash memory also brings new constraints to the management. As a result, management schemes designed for SLC flash memory could not be directly applied to MLC flash memory, or a severe performance degradation would be suffered. This paper proposes a translation layer above flash-memory medium to make it transparent to management schemes. With our translation layer, management schemes designed for SLC flash memory or MLC flash memory could be directly applied without considering the type of underlying flash memory medium. Our experiment results show that only a minor overhead would be suffered while applying our translation layer in flash-memory storage systems.