Towards the automated generation of hard disk models through physical geometry discovery

As the High Performance Computing industry moves towards the exascale era of computing, parallel scientific and engineering applications are becoming increasingly complex. The use of simulation allows us to predict how an application's performance will change with the adoption of new hardware or software, helping to inform procurement decisions. In this paper, we present a disk simulator designed to predict the performance of read and write operations to a single hard disk drive (HDD). Our simulator uses a geometry discovery benchmark (Diskovery) in order to estimate the data layout of the HDD, as well as the time spent moving the read/write head. We validate our simulator against two different HDDs, using a benchmark designed to simulate common disk read and write patterns, demonstrating accuracy to within 5% of the observed I/O time for sequential operations, and to within 10% of the observed time for seek-heavy workloads.