Computer Sciences Dept.

Deconstructing Storage Arrays

Timothy E.Denehy, John Bent, Florentina I.Popovici, Andrea Arpaci-Dusseau, Remzi Arpaci-Dusseau

We present Shear; a user-level software tool that characterizes RAID storage arrays. Shear employs a set of controlled algorithms combined with statistical techniques to automatically determine the important properties of a RAID system. We illustrate the correctness of Shear by running it upon numerous simulated configurations, and then verify its real-world applicability by applying Shear to both software-based and hardware-based RAID systems. Finally, we demonstrate the utility of Shear through two case studies. First, we show how Shear can be used in a storage management environment to verify RAID construction and detect failures. Second, we show how an operating system can use Shear to automatically tune its storage subsystems to specific RAID configurations.

Download this report (PDF)

Return to tech report index

Computer Science | UW Home