Shedding Light in the Black-Box : Structural Modeling of Modern Disk Drives

The performance of computer systems depends on relatively slow disk I/O performance. In order to improve the disk I/O performance, it is required to reduce a mechanical delay induced by the disk I/O operations. Several approaches have been proposed for it. However, because hard-disk storage hides too much information to the outside world, it makes difficult to predict exact internal layout of disk storage. This paper introduces a technique which brings this black box to light empirically. The technique can be called a gray-box approach due to the use of some prior knowledge about disk drives. We propose a new algorithm that extract disk model parameters and build overall multi-dimensional disk structural model for several up-to-data IDE disk drives whose internals are known as a black-box. We validate the model accuracy through seek time analysis. We expect our modeling result can be applied to many researches optimizing disk I/O performance.