Virtual duplication and mapping prefetching for emerging storage primitives in NAND flash memory storage systems

摘要

NAND flash memory has become the mainstream storage medium for both enterprise high performance computers and embedded systems. However, over the past several decades, the storage primitives that access secondary storage have remained unchanged, forcing NAND flash memory to serve merely as a block device like hard disk drive. Recently, several emerging storage primitives have been presented to explore the potential value of non-volatile memory devices. Although these primitives can significantly boost the access performance by providing virtual to logical address mappings, they still suffer from large RAM footprint to maintain the address mapping table and require further support for update operations. This paper presents ESP to optimize E merging S torage P rimitives with virtualization for flash memory storage systems. We propose two optimization strategies, virtual duplication and mapping prefetching to solve the critical issues in existing emerging storage primitives. The objective is to reduce unnecessary flash memory accesses and keep RAM footprint of address mapping table well under control. We have evaluated ESP on an embedded development platform. Experimental results show that ESP can significantly improve the write/read performance and reduce over 30% of garbage collection operations.