Performance and Reliability Enhanced SSD Storage System: Using HDD as Buffer

• Main Authors: Po-wei Wu, 吳柏緯
• Other Authors: Jen-wei Hsieh
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/09282037825771271308

碩士 === 國立臺灣科技大學 === 資訊工程系 === 102 === Several researches have been proposed and focus on hybrid storage systems, most of the researches used hard-disk drives (HDDs) as the primary storage devices and solid-state drives (SSDs) as a cache to improve the performance of the storage systems. Some of researches used SSDs as the primary storage devices and HDDs as a write bu er for writing random requests to extend the overall lifetime of the storage systems. However, there are no any previous researches considered the factor that in state-of-art or near future SSD not only read speed but also write speed are overwhelming HDD. Most of the managements of these researches proposed are out-of-date, they do not fully exploiting the read/write performance of SSD. In this paper, we proposed a novel management strategy that we try to use HDD as a bu er for garbage collection of SSD to improve the overall lifetime of the storage system and meanwhile maintaining the performance of the storage system at SSD level. The experiment results show that we improved the overall lifetime of the hybrid storage system by 23% to 409% under di erent traces. And we proved that the performance of the proposed stragegy is not e ect by di erent characteristics of workloads. We also used the strategy we designed that reclaiming data from HDD back to SSD to achieve inter-wear leveling of the system. The proposed management not only provided lifetime extend by reducing unnecessary writes but also maintained the performance at SSD level and achieved great intra/inter-wear leveling of the hybrid storage system.