It is known that measuring performance is one of the most challenging tasks in system administration. It requires proper configuration and a good understanding of the results. Fortunately, Linux systems offer a wide variety of tools for obtaining performance metrics. In this blog post, we will focus on the instrumentation capabilities of the Linux kernel and some interesting methods of analyzing the results. The importance of the kernel lies in the fact that usage information related to CPU, memory, disk space, or network interfaces is always passing through it, and it cannot be bypassed.