The DiskSim Simulation EnvironmentVersion 3.0 Reference ManualJohn S. Bucy, Gregory R. Ganger, and ContributorsJanuary 2003CMU-CS-03-102School of Computer ScienceCarnegie Mellon UniversityPittsburgh, PA 15213AbstractDiskSim is an efficient, accurate and highly-configurable disk system simulator developed to support research intovarious aspects of storage subsystem architecture. It includes modules that simulate disks, intermediate controllers,buses, device drivers, request schedulers, disk block caches, and disk array data organizations. In particular, the diskdrive module simulates modern disk drives in great detail and has been carefully validated against several productiondisks (with accuracy that exceeds any previously reported simulator).This manual describes how to configure and use DiskSim, which has been made publicly available with the hopeof advancing the state-of-the-art in disk system performance evaluation in the research community. The manual alsobriefly describes DiskSim’s internal structure and various validation results.Keywords: storage system, disk simulator, disk modeliContentsContents i1 Introduction 11.1 What DiskSim Does . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 What DiskSim Does Not Do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 Limitations and Advantages of Version 3.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3.1 Diskmodel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3.2 Libparam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.4 Known Bugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.5 Organization of Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.5.1 Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Running DiskSim 32.1 Parameter Overrides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.2 Example Command Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 The Parameter File 53.1 Global Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.2 Stats Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.2.1 Bus Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.2.2 Controller Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.2.3 Device Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.2.4 iodriver Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.2.5 Process-flow Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.3 iosim Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.4 I/O Subsystem Component Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.4.1 Device Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.4.2 Buses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93.4.3 Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103.4.4 Storage Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103.4.5 Disks . . . . . . . …