Compression Support for Flash Translation Layer

NAND flash memory has many advantageous features as a storage medium, such as superior performance, shock resistance, and lowpower consumption. However, the erase-before-write nature and the limited number of write/erase cycles are obstacles to the promising future of NAND flash memory. An intermediate software layer called Flash Translation Layer (FTL) is used to overcome these obstacles. In this paper, we present a flash translation layer called zFTL which has data compression support to reduce the amount of data written to flash memory. zFTL is based on page-level mapping, but it is extended to support on-line, transparent data compression and decompression. We implement zFTL on the MTD layer of the Linux kernel. Our experimental results with five workloads from Linux and Windows show that zFTL improves the write amplification factor by 27% ~ 92%.