Summary: Microbenchmark­based Extraction of
Local and Global Disk Characteristics
Nisha Talagala, Remzi H. Arpaci­Dusseau, and David Patterson
Computer Science Division
University of California, Berkeley
Abstract
Obtaining timely and accurate information about the low­level characteristics of disk drives presents a problem
for system design and implementation alike. This paper presents a collection of three disk microbenchmarks which
combine to empirically extract a relevant subset of disk geometry and performance parameters in an efficient and
accurate manner, without requiring a priori information of the drive being measured. Novel among the benchmarks is
the utilization of linearly­increased stride to glean a spectrum of low­level details including head­switch and cylinder­
switch times while factoring out rotational effects. A bandwidth benchmarkextracts the zone profile of disks, revealing
that the previously preferred linear model of zone bandwidth is less accurate than a quadratic model. A seek profile
is also generated, completing the trio of benchmarks. Data is collected from a broad class of modern disks, including
five SCSI, two IDE, and two simulated drives.
1 Introduction
Theories come and go, but fundamental data always remains.
Mary Leakey
Sustained innovation in the hard­drive industry has spurred incredible advances in disk technology. Both perfor­
mance and capacity have benefited -- bandwidth is increasing at sixty percent per year, and capacity is growing at

Source: Arpaci-Dusseau, Remzi - Department of Computer Sciences, Department of Computer Sciences, University of Wisconsin at Madison

Collections: Computer Technologies and Information Sciences