SPEK: a storage performance evaluation kernel module for block-level storage systems under faulty conditions

This paper introduces a new benchmark tool, SPEK (storage performance evaluation kernel module), for evaluating the performance of block-level storage systems in the presence of faults as well as under normal operations. SPEK can work on both direct attached storage (DAS) and block level networked storage systems such as storage area networks (SAN). Each SPEK consists of a controller, several workers, one or more probers, and several fault injection modules. Since it runs at kernel level and eliminates skews and overheads caused by file systems, SPEK is highly accurate and efficient. It allows a storage architect to generate configurable workloads to a system under test and to inject different faults into various system components such as network devices, storage devices, and controllers. Available performance measurements under different workloads and faulty conditions are dynamically collected and recorded in SPEK over a spectrum of time. To demonstrate its functionality, we apply SPEK to evaluate the performance of two direct attached storage systems and two typical SANs under Linux with different fault injections. Our experiments show that SPEK is highly efficient and accurate to measure performance for block-level storage systems.