A large number of existing parallel storage systems consist of hybrid storage components, including solid-state drives (SSD), hard disks (HDD), and tapes. Compared with high-speed storage components (e.g. SSD and HDD), tapes inevitably become an I/O performance bottleneck. Prefetching and caching are commonly employed techniques to boost I/O performance by increasing the data hitting rate of high-end storage components. However, prefetching in the context of hybrid storage systems is technically challenging due to an interesting dilemma: aggressive prefetching schemes can efficiently reduce I/O latency, whereas overaggressive schemes may waste I/O bandwidth by transferring useless data from HDDs to SSDs or from tapes to HDDs. In this research project, called FastStor, we investigate new data-mining-based multilayer prefetching techniques to improve performance of hybrid storage systems. The goals of this research are to (1) design data-mining algorithms for multilayer prefetching; (2) develop predictive parallel prefetching mechanism for SSD-based storage systems; (3) implement parallel data transfer among SSDs, HDDs, and tapes; (4) develop meta-data management schemes; and (5) implement a simulation framework named FastStor-SIM. The developed toolkit can be used to improve the I/O performance of data centers with hybrid storage systems. The research findings of this project are published in conferences or journals for public knowledge. Through the collaboration of Auburn University, South Dakota School of Mines and Technology, and the University of Southern Mississippi, PIs promote learning and training by exposing graduate and undergraduate students to technological underpinnings in the fields of storage systems.
