Exploiting the Future Reference in Write Buffer Management Design for SSDs

Abstract

We present some practical issues in designing the write buffer management scheme for SSDs (Solid-State Drives). In SSDs with SATA interface, there exist the pending I/O commands in NCQ (Native Command Queueing), and it can be effectively exploited for write buffer management. Based on this fact, we propose an efficient write buffer management scheme that exploits the future buffer reference pattern from I/O commands queued in NCQ. We also discuss the relationship between the buffer size and the effectiveness of NCQ-awareness in our scheme. Finally, we show that the proposed scheme improves the performance of write buffer for some workloads. Index Terms—NAND flash memory, NCQ, write buffer, SSDs. presented. Section III describes the proposed write buffer management scheme, and discusses an appropriate buffer size in our scheme for obtaining the effectiveness of NCQ-awareness. Finally, Section IV and Section V present the experimental results and concluding remark, respectively.