CMU-CS-00-100
Computer Science Department
School of Computer Science, Carnegie Mellon University



CMU-CS-00-100

Modeling and Scheduling of MEMS-Based Storage Devices

John Linwood Griffin, Steven W. Schlosser, Gregory R. Ganger, David F. Nagle
November 1999


Has been superceded by.....

Modeling and Performance of MEMS-based Storage Devices
John Linwood Griffin, Steven W. Schlosser, Gregory R. Ganger, David F. Nagle
In Proceedings ACM SIGMETRICS 2000,
International Conference on Measurement and Modeling of Computer Systems
,
June 2000, pp 56:65.

MEMS-based storage devices are seen by many as promising alternatives to disk drives. Fabricated using conventional CMOS processes, MEMS-based storage consists of thousands of small, mechanical probe tips that access gigabytes of high-density, nonvolatile magnetic storage. This paper takes a first step towards understanding the performance characteristics of these devices by mapping them onto a disk-like metaphor. Using simulation models based on the mechanics equations governing the devices' operation, this work explores how different physical characteristics (e.g., actuator forces and per-tip data rates) impact the design trade-offs and performance of MEMS-based storage. Overall results indicate that average access times for MEMS-based storage are 6.5 times faster than for a modern disk (1.5 ms vs. 9.7 ms). Results from filesystem and database benchmarks show that this improvement reduces application I/O stall times up to 70%, resulting in overall performance improvements of 3X.


and by.....


Operating System Management of MEMS-based Storage Devices
John Linwood Griffin, Steven W. Schlosser, Gregory R. Ganger, David F. Nagle
In 4th USENIX Symposium on Operating Systems Design and Implementation (OSDI), October 2000.

MEMS-based storage devices promise significant performance, reliability, and power improvements relative to disk drives. This paper explores how the physical characteristics of these devices change four aspects of operating system management: request scheduling, data placement, failure management, and power management. Adaptations of disk request scheduling algorithms are found to be appropriate for these devices; however, new data placement schemes are shown to better match their differing mechanical positioning characteristics. With aggressive internal redundancy, MEMS-based storage devices can tolerate failure modes that cause data loss for disks. In addition, MEMS-based storage devices enable a finer granularity of OS-level power management because the devices can be stopped and started rapidly and their mechanical components can be individually enabled or disabled to reduce power consumption.


Return to: SCS Technical Report Collection
School of Computer Science homepage

This page maintained by reports@cs.cmu.edu