In this article, we will explore the concept of CPU usage and its significance in the Linux environment. We will discuss how CPU usage is measured, its importance for system performance monitoring, and provide practical examples and commands to analyze and manage CPU usage in Linux.

CPU usage is a critical metric in determining the overall performance and health of a Linux system. It represents the amount of processing power utilized by the system at any given time. Monitoring CPU usage allows system administrators and developers to identify bottlenecks, optimize resource allocation, and ensure efficient utilization of hardware resources.

Examples:

1. Checking CPU Usage with top command: The 'top' command is a powerful tool to monitor CPU usage in real-time. Open a terminal and run the following command:

   top

   This will display a live-updating list of processes and their CPU usage. The '%CPU' column represents the percentage of CPU time consumed by each process.

2. Analyzing CPU Usage with mpstat: The 'mpstat' command provides detailed CPU statistics, including individual CPU core usage. Run the following command to install 'mpstat' if it is not already available:

   sudo apt-get install sysstat

   Once installed, run the following command to check CPU usage statistics:

   mpstat -P ALL

   This will display CPU usage information for each core, including metrics like user, system, and idle time.

3. Monitoring CPU Usage with sar: The 'sar' command is another useful tool for monitoring CPU usage over a period of time. Install 'sar' by running the following command:

   sudo apt-get install sysstat

   Once installed, run the following command to generate a report of CPU usage for the last 10 minutes:

   sar -u 10

   This will display CPU usage statistics at regular intervals, allowing you to analyze trends and identify patterns.