A performance model of synchronization mechanisms in a file system

This paper presents a practical method for evaluating file systems in which synchronization mechanisms are modeled using measurable parameters. A queueing network model of a file system is introduced. The model allows various type of locks, multiple classes of transactions, and files and sectors shared by different types of transactions to be represented. The model parameters are estimated from the values of measurable quantities. The service times of lock servers are calculated as functions of the loads on all service centers. The various lock granularities can be represented by this model. Performance measures applicable to the evaluation of computer systems are introduced and evaluated. An example involving a file system and measurement data collected in a small business installation is given to compare performance measures provided by the simulation and analytic models.