ROCO:Using a Solid State Drive Cache to Improve the Performance of a Host-Aware Shingled Magnetic Recording Drive  

作　　者：Wen-Guo Liu Ling-Fang Zeng Dan Feng Kenneth B.Kent 

机构地区：[1]School of Computer Science and Technology,Huazhong University of Science and Technology,Wuhan 430074,China [2]Faculty of Computer Science,University of New Brunswick,Fredericton,E3B 5A3,Canada

出　　处：《Journal of Computer Science & Technology》2019年第1期61-76,共16页计算机科学技术学报（英文版）

基　　金：the National Natural Science Foundation of China under Grant No.61472153.

摘　　要：Shingled magnetic recording (SMR)can effectively increase the capacity of hard disk drives (HDDs).Hostaware SMR (HA-SMR)is expected to be more popular than other SMR models because of its backward compatibility and new SMR-specific APIs.However,an HA-SMR drive often suffers performance degradation under write-intensive workloads because of frequent non-sequential writes buffered in the disk cache.The non-sequential writes mainly come from update writes,small random writes and out-of-order writes.In this paper,we propose a hybrid storage system called ROCO which aims to use a solid state drive (SSD)cache to improve the performance of an HA-SMR drive.ROCO reorders out-of-order writes belonging to the same zone and uses the SSD cache to absorb update writes and small random writes.We also design a data replacement algorithm called CREA for the SSD cache.CREA first conducts zone-oriented hot/cold data identification to identify cold-cached zones and hot-cached zones,and then evicts data blocks belonging to colder zones with higher priorities that can be sequentially written or written through host-side read-modify-write operations.It gives the lowest priority to data blocks belonging to the hottest-cached zone that have to be non-sequentially written.Experimental results show that ROCO can effectively reduce non-sequential writes to the HA-SMR drive and improve the performance of the HA-SMR drive.

关 键 词：solid state reordering zone-oriented DRIVE (SSD)cache host-aware shingled magnetic recording (HA-SMR)drive zone-oriented block hot/cold DATA identification DATA replacement algorithm 

分 类 号：TP[自动化与计算机技术]