Data Placement Based on the Seek Time Analysis of a MEMS-based Storage Device

Abstract

Reducing access times to secondary I/O devices has long been the focus of many systems researchers. With traditional disk drives, access time is the composition of transfer time, seek time and rotational latency, so many techniques as to minimize these factors, such as ordering I/O requests or intelligently placing data, have been developed. MEMS-based storage devices are seen by many as a replacement or an augmentation for modern disk drives, but algorithms for reducing access time for MEMS-based storage are still poorly understood. These devices, based on MicroElectroMechanical systems (MEMS), use thousands of active read/write heads working in parallel on a non-rotating magnetic substrate, eliminating rotational latency from the access time equation. This leaves seek time as the dominant variable. Therefore, new data layout techniques based on minimizing the unique seek time characteristics of a MEMS-based storage device can be developed. This paper begins to examine the access qualities of a MEMS-based storage device, and based on experimental simulation, develops an understanding of the seek time characteristics of such a device. These characteristics then allow us to identify equivalent regions in which to place data for improved access.