How to Check and Monitor Running Processes in Linux

 Introduction

Processes are the running programs on your Linux system. Monitoring them is critical for diagnosing performance issues, managing system resources, and troubleshooting errors. Linux provides several tools to check, monitor, and control processes effectively.

Step 1: View All Running Processes

Use the ps command:

ps aux

➡️ This shows all processes with details like process ID (PID), user, CPU usage, memory usage, and command.

Step 2: Real-Time Process Monitoring with top

Run:

top

➡️ This displays processes in real-time with resource consumption.

You can press q to quit.

For a modern interface with more details, install and use htop:

sudo apt install htop # Debian/Ubuntu

sudo yum install htop # CentOS/RedHat

htop

Step 3: Find a Specific Process

To search for a process by name:

ps aux | grep processname

➡️ Replace processname with the name of the process you’re looking for.

Step 4: Kill a Process

If a process is unresponsive, kill it using its PID:

kill -9 PID

➡️ Replace PID with the actual process ID from the ps or top output.

Step 5: Monitor System Activity with vmstat

Use:

vmstat 2

➡️ This displays real-time information about processes, memory, CPU, and I/O every 2 seconds.

Conclusion

Monitoring processes is an essential skill for Linux administrators. With tools like ps, top, and htop, you can quickly identify resource-hungry processes, troubleshoot performance problems, and keep your system running smoothly.