R&D: DSTL, Demand-Based Shingled Translation Layer for Enabling Adaptive Address Mapping on SMR Drives

ACM Transactions on Embedded Computing Systems has published an article written by Shuo-Han Chen, Academia Sinica, Yi-Jing Chuang, National Tsing Hua University, Yuan-Hao Chang, Academia Sinica, Yu-Pei Liang, National Tsing Hua University, Hsin-Wen Wei, Takang University, and Wei-Kuan Shih, National Tsing Hua University.

Abstract: “Shingled Magnetic Recording (SMR) is regarded as a promising technology for resolving the areal density limitation of conventional magnetic recording hard disk drives (HDDs). Among different types of SMR drives, drive-managed SMR (DM-SMR) requires no changes on the host software and is widely used in today’s consumer market. DM-SMR employees a shingled translation layer (STL) to hide its inherent sequential-write constraint from the host software and emulate the SMR drive as a block device via maintaining logical to physical block address mapping entries. However, because most of existing STL designs do not simultaneously consider the access pattern and the data update frequency of incoming workloads, those mapping entries maintained within STL cannot be effectively managed, thus inducing unnecessary performance overhead. To resolve the inefficiency of existing STL design, this paper proposes a demand-based shingled translation layer (DSTL) to simultaneously consider the access pattern and update frequency of incoming data streams to enhance the access performance of DM-SMR. The proposed design was evaluated by a series of experiments and the results show that the proposed DSTL can outperform other SMR management approach by upto 86.69% in terms of read/write performance.“