Design and Implementation of Fault Injector for Hybrid Heterogeneous Storage System

Compared with traditional HDD(Hard Disk Drive), SSD (Solid-state drive) has the advantages of fast read and write performance, light weight and low energy consumption. However, the cost of per GB data by SSD is much more than that by HDD. Therefore, the hybrid heterogeneous storage system based on SSD and HDD has become the main stream of development of storage systems. In the hybrid storage system, the internal structure, working principle and failure mechanism of different storage devices are very different, which brings great challenges to the reliability of the storage system. Therefore, how to evaluate the reliability of hybrid heterogeneous storage system has become an important research area. The former evaluation method lacks the consideration of the heterogeneity of storage system and the failure rate of storage medium. To solve these problems, we design and implement a fault injector for hybrid heterogeneous storage systems by using the Systemtap and shell script to inject fault. The fault types are classified into four types: storage media failures, memory failures, CPU failures and network adapter failures. In addition, for the storage media failures, we establish corresponding function model of fault rate according to the related research on HDD and SSD failure rate and use those models to inject faults. By this way, in a short time we can evaluate the reliability of hybrid heterogeneous storage system for long-term operation. The experimental results show that the fault injector can effectively simulate the hardware failures in the hybrid heterogeneous storage system.