Appears in Proceedings of the 4th Symposium on Operating Systems Design and Implementation, 2000. Supercedes Carnegie Mellon University SCS Technical Report CMU-CS-00-136, May 2000.
John Linwood Griffin, Steven W. Schlosser, Gregory R. Ganger and David F. Nagle
Dept. Electrical and Computer Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
MEMS-based storage devices promise significant performance, reliability, and power improvements relative to disk drives. This paper compares and contrasts these two storage technologies and explores how the physical characteristics of MEMS-based storage devices change four aspects of operating system (OS) management: request scheduling, data placement, failure management, and power conservation. Straightforward adaptations of existing disk request scheduling algorithms are found to be appropriate for MEMS-based storage devices. A new bipartite data placement scheme is shown to better match these devices' novel mechanical positioning characteristics. With aggressive internal redundancy, MEMS-based storage devices can mask and tolerate failure modes that halt operation or cause data loss for disks. In addition, MEMS-based storage devices simplify power management because the devices can be stopped and started rapidly.