Proceedings of the ACM Sigmetrics Conference, May 1995, pp. 146-156.
OnLine Extraction of SCSI Disk Drive Parameters
Bruce L. Worthington, Gregory R. Ganger, Yale N. Patt, and John Wilkes*
University of Michigan
Sophisticated disk scheduling algorithms require accurate and detailed disk drive specifications, including inormation on mechanical delays, onboard caching and prefetching algorithms, command processing and protocol overheads, and logicaltophysical block mappings. Comprehensive disk models used in storage subsystem design require similar levels of detail. This report describes a suite of generalpurpose techniques and algorithms for acquiring the necessary data from SCSI disks via the ANSIstandard interface. The accuracy of the extracted information is demonstrated by comparing the behavior of a configurable disk simulator against actual disk drive activity. Detailed measurements extracted from several SCSI disk drives are provided.