WIKI webhosting

SystemTap provides tools for monitoring and analyzing the performance of the Linux operating system at the kernel level. This article will guide you through the process of installing, configuring, and using SystemTap on CentOS 7, enabling you to effectively monitor and diagnose the kernel-level system.

Installation of SystemTap

Before proceeding with any steps, ensure that your system is updated using the sudo yum update command. After updating, you can proceed with the installation of SystemTap.

1. Installation of Packages: To install SystemTap and necessary dependencies, run the following command:

   sudo yum install systemtap systemtap-runtime kernel-devel
   

   It's important to have the kernel-devel package installed corresponding to your kernel version. You can check the kernel version using the uname -r command.

2. Installation of Debug Symbols: For more detailed diagnostics, it's necessary to install debug symbols for the kernel. This can be done using the debuginfo repository:

   sudo yum install yum-utils
   sudo debuginfo-install kernel-$(uname -r)
   ​

Configuration of SystemTap

Before using SystemTap for the first time, several configuration steps need to be performed:

1. Preparation of Scripts: SystemTap uses scripts to define monitoring and diagnostic tasks. A script is a text file with the .stp extension containing SystemTap definitions and commands.

2. Test Script: To verify that SystemTap is properly installed and configured, create a simple test script named hello_world.stp:

   global counter
   
   probe vfs.read {
     counter++
   }
   
   probe timer.s(5) {
     println("Number of VFS read operations: ", counter)
     exit()
   }
   

2. This script counts VFS read operations and prints the count every 5 seconds.

Execution and Analysis of Script

To execute the script, use the command sudo stap <script_name.stp>. For example:

sudo stap hello_world.stp

After execution, the script will monitor read operations in the virtual file system (VFS) and print the count of these operations every 5 seconds. This simple example illustrates how SystemTap can be used to monitor specific events in the system.

Advanced Monitoring and Diagnostics

SystemTap allows for much more complex diagnostic tasks, including monitoring network performance, analyzing application performance, or detecting kernel deadlocks. Examples of advanced scripts include:

• Network Traffic Monitoring: A script to analyze the amount of data transferred on a network interface.
• Application Performance Analysis: Monitoring the time spent in various application functions.

 

SystemTap is a powerful tool for developers and system administrators to monitor and diagnose Linux operating systems at the kernel level. While its basic usage is relatively straightforward, effective utilization in advanced scenarios requires familiarity with extensive documentation and script examples.