Disks Are Like Snowflakes: No Two Are Alike
13th Workshop on Hot Topics in Operating Systems (HotOS 2011). Supersedes Carnegie Mellon University Parallel Data Lab Technical Report CMU-PDL-11-102. February 2011.
Elie Krevat*, Joseph Tucek†, and Gregory R. Ganger*
*Electrical and Computer Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
Gone are the days of homogeneous sets of disks. Even disks of a given batch, of the same make and model, will have significantly different bandwidths. This paper describes the disk technology trends responsible for the now-inherent heterogeneity of multi-disk systems and disk-based clusters, provides measurements quantifying it, and discusses its implications for system designers.
KEYWORDS: adaptive zoning, disk performance, linear density, track density, variable recording