HB-Storage: Optimizing SSDs with a HDD Write Buffer

Abstract

In recent years, flash memory based storage device SSDs (solid state drives) have been regarded as the storage devices of next generation to replace HDDs (hard disk drivers). However, the high price of SSDs, especially those with high performance, results in the situation that SSDs and HDDS are both popularly used in real applications. In order to integrate the merits of SSDs and HDDS, it has become a hot research topic that using HDDs for SSDs to construct a hybrid storage system. The goal of this paper is to use the cheap low-end SSD and HDD to build a hybrid storage system with high efficiency, which is called HB-Storage. HB-Storage considers the characters of SSDs and HDDs, and builds a HDD write buffer to optimize the SSD write request. The write buffer is designed based on the data access load statistics. As a consequence, HB-Storage can utilize the higher read performance of SSDs, and can also improve the random write latency of SSDs. The experimental results show that HB-Storage can maintain a high read performance and significantly reduce the write requests on the SSD, and thus has higher overall performance.