On Improving the Write Responsiveness for Host-Aware SMR Drives

• Published in: IEEE transactions on computers Vol. 68; no. 1; pp. 111 - 124
• Main Authors: Yang, Ming-Chang, Chang, Yuan-Hao, Wu, Fenggang, Kuo, Tei-Wei, Du, David H. C.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-01-2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Cache storage; Disk drives; Hard disks; Host-aware; long latency behavior; Magnetic recording; Perpendicular magnetic recording; persistent cache; Resource management; Shingled magnetic recording; shingled magnetic recording (SMR); Storage management; Workloads
• ISSN: 0018-9340; 1557-9956
• DOI: 10.1109/TC.2018.2845383

This paper presents a Virtual Persistent Cache design to remedy the long latency behavior and to ultimately improve the write responsiveness of the Host-Aware Shingled Magnetic Recording (HA-SMR) drives. Our design keeps the cost-effective model of the existing HA-SMR drives, but at the same time asks the great help from the host system for adaptively providing some computing and management resources to improve the drive performance when needed. The technical contribution is to trick the HA-SMR drives by smartly reshaping the access patterns to HA-SMR drives, so as to avoid the occurrences of long latencies in most cases and thus to ultimately improve the drive performance and responsiveness. We conduct experiments on real Seagate 8 TB HA-SMR drives to demonstrate the advantages of Virtual Persistent Cache over the real workloads from Microsoft Research Cambridge. The results show that the proposed design can remedy most of the long latencies and improve the drive performance by at least 58.11 percent, under the evaluated workloads.