How to use atop command.

Posted on January 15, 2024 by darshin

Monitoring system resources is crucial for maintaining optimal performance and troubleshooting issues. One powerful tool for this task is the atop command, which provides detailed insights into various system metrics. In this article, we will explore the usage of the atop command, covering its features and providing numerous examples for a comprehensive understanding.

Installing atop

Before diving into usage, ensure that atop is installed on your system. You can install it using the package manager for your Linux distribution. For example, on Debian-based systems, use:

sudo apt-get install atop

Launching atop

To start monitoring your system using atop, simply run the following command in the terminal:

sudo atop

This will launch the atop interactive console.

Navigating atop Interface

Once atop is running, you’ll be presented with an interactive console showing real-time system statistics. Here’s a breakdown of the main sections:

1. Header Section: Displays key information such as the current time, uptime, number of tasks, load averages, and more.

2. Global CPU Usage: Provides an overview of CPU usage across all cores.

3. Memory Usage: Details about physical and swap memory usage.

4. Disk I/O: Information on disk activity, including read and write rates.

5. Network Activity: Shows network statistics like incoming and outgoing data rates.

6. Processes Listing: A table of processes, sorted by resource usage. Press c to toggle between different columns.

7. Per-CPU Statistics: Breakdown of CPU usage for each core.

Customizing atop Output

You can customize the atop output by toggling between different views and sorting options. Here are some useful commands:

• Changing Sorting Order: Press p to change the sorting order of processes based on CPU usage, m for memory, d for disk activity, and n for network activity.

• Filtering Processes: Use u to filter processes for a specific user.

• Highlighting Processes: Press x to highlight a specific process in the process list.

• Viewing Detailed Information: Move the cursor to a process and press d to see detailed information about that process.

• Changing Refresh Interval: Use s to change the refresh interval. By default, it’s set to 1 second.

Examples

Example 1: Basic atop Usage

sudo atop

This will launch atop in the interactive mode, showing real-time system statistics.

Example 2: Sorting Processes by CPU Usage

sudo atop -c

Launch atop with process listing sorted by CPU usage.

Example 3: Monitoring Disk Activity

sudo atop -d

Focus on disk I/O statistics.

Example 4: Filtering Processes for a User

sudo atop -u username

Display processes for a specific user.

Example 5: Changing Refresh Interval

sudo atop -s 5

Set the refresh interval to 5 seconds.

Conclusion

The atop command provides a comprehensive view of system resources, making it a valuable tool for system administrators and power users. By understanding its features and experimenting with various options, you can gain deep insights into your system’s performance and identify potential bottlenecks or issues.