MScache: A Buffer Management Scheme Based on Page-Level Address Mapping for NAND-Flash SSD

摘要

NAND Flash has been widely used in consumer electronic devices, especially in SSDs (Solid State Disks). However, with the process scaling down, its inherent imperfection will be more severe, such as the limited endurance, asymmetric speed of programming and read. While a traditional cache mechanism can improve the performance partly, it can't reduce the unnecessary writes to NAND Flash resulting from read miss; besides, it is still difficult for most current cache strategies to respond diverse patterns of access rapidly. In this paper, a novel Master and Slave Cache (MScache) based on page-level mapping and hybrid buffer management strategy is proposed to reduce the redundant writes to NAND Flash, improve access speed and prolong SSD's lifespan. We assess the scheme with three typical traces and three classical cache schemes are compared. The simulation results show that the proposed MScache can achieve dramatically writes and erases reduction.