基于4KB数据块映射的固态硬盘算法

摘要

固态硬盘(Solid-State Drive,SSD)采用NAND型闪存(Flash Memory)为主要存储介质,闪存的读写不同于其他介质,需要闪存转换层(Flash Translation Layer,FTL)对闪存的存储空间进行管理.传统方式的映射算法随着页面(Pagesize)的逐渐扩大,在随机数据块写入的速度方面难以提升.针对这个问题,提出一种基于4 KB数据块映射的闪存转换层算法,固态硬盘控制器芯片采用110 nm工艺实现,集成了SATA-II接口(3 Gb/s数据传输速率),最大可以并行驱动5通道的闪存芯片.该算法结合芯片的内部资源,经过了可靠性检测,达到了预期的可靠性和读写速度.%NAND Flash memory has been applied as the storage media in Solid State Drive(SSD).It has some unique features,for example,it needs Flash Memory Translation Layer (FTL) to manage the storage space for high read & write performance,liability and life-time guarantee.Traditional algorithms are but not the best solutions for today's NAND flash memory while the page size and block size have grown up quickly in the past years.Those page size based algorithms were proven not good performance in random data access,which measured in 4 KB byte data throughput(called as “IOPS”,in/out per second).The paper proposed a 4 KB size mapping FTL algorithm.This algorithm was verified on a SSD controller,a real silicon chip manufactured by 110 nm process.The chip had SATA-II interface with 3 Gb/s data transfer rate and five Flash memory accessing buses to drive up to five Flash memory channels in parallel.The algorithm supported by the chip's internal resources passed the reliability test and presented the expected read & write speed.