CFStore: Boosting Hybrid storage performance by device crossfire

Hybrid storage is widely implemented as it satisfies the requirements of capacity and performance in an economically viable fashion. With the fast technical improvement, Hybrid storage systems consisting of several types of SSDs will be adopted gradually. Existing works mostly concentrate on thoroughly utilizing high-performance device but neglect the capability of low-performance device. This paper proposes a device crossfire method to boost hybrid storage performance by efficiently leveraging both high-performance and low-performance devices. Performance-critical data are appropriately off-loaded to low-performance device to exploit access parallelism. The implemented storage system CFStore exhibits good performance during experiments. Compared to famous hybrid storage system Hystor, CFStore improves throughput by 17.9%–42.6%, and reduces latency by 15.9%–35.0%.