The first step in improving Linux performance is quantifying it, but how exactly do you quantify performance for Linux or for comparable systems? In this article, members of the IBM Linux Technology Center share their expertise as they describe how they ran several benchmark tests on the Linux 2.4 and 2.5 kernels late last year. The benchmarks provide coverage for a diverse set of workloads, including Web serving, database, and file serving. In addition, we show the various components of the kernel (disk I/O subsystem, for example) that are stressed by each benchmark.