DiskSim is a resource, The DiskSim Simulation Environment. From the home page:
DiskSim is an efficient, accurate, highly-configurable disk system simulator developed at the University of Michigan and enhanced at CMU to support research into various aspects of storage subsystem architecture. It is written in C and requires no special system software (just basic POSIX interfaces). DiskSim includes modules for most secondary storage components of interest, including device drivers, buses, controllers, adapters, and disk drives. DiskSim also includes support for a number of externally-provided trace formats and internally-generated synthetic workloads, and includes hooks for inclusion in a larger scale system-level simulator.