Monitoring system performance is crucial for maintaining a healthy Linux server. The top and htop commands are two powerful tools for checking real-time system resource usage, including CPU, memory, disk, and process statistics. Here’s how to use both tools to monitor your system performance.

Using top Command

1. Launch the top Command

The top command shows a dynamic, real-time view of the system’s processes, CPU usage, memory usage, and more.

   top

2. Understanding top Output

The top command displays several key metrics:

• PID: Process ID
• USER: The user running the process
• PR: Process priority
• %CPU: CPU usage by the process
• %MEM: Memory usage by the process
• COMMAND: The name of the command running

3. Sort Processes

Press Shift + P to sort processes by CPU usage or Shift + M to sort by memory usage.

4. Kill a Process

If you want to terminate a process, press k and then enter the PID of the process you wish to kill.

5. Quit top

Press q to exit top.

Using htop Command

1. Install htop

If htop is not already installed, you can install it with the following command:

sudo apt install htop

2. Launch the htop Command

To launch htop, simply type:

htop

3. Understanding htop Output

htop provides a more user-friendly, colorful interface that displays the same information as top, but with additional features:

• Process list with CPU and memory usage in bars
• Load average and uptime displayed at the top
• Search and filter options for easier navigation

4. Sort Processes

You can sort processes by CPU or memory usage by clicking on the respective column headers or by pressing F6 and selecting the column to sort by.

5. Manage Processes

To kill or send signals to a process, select the process and press F9 to choose a signal to send, such as SIGKILL.

6. Quit htop

To exit htop, press F10 or q.

Conclusion

• Use top for quick, real-time monitoring of system performance via the command line.
• Use htop for a more user-friendly, visually appealing interface with additional features like filtering, sorting, and easier process management.

By mastering these tools, you can keep track of your Linux server’s performance and quickly identify any resource-heavy processes or bottlenecks.