SYSTEM CONTROL ROOM

📊 Monitoring Processes & System Health

Learn how Linux professionals monitor running applications, performance, and system resources.

🚨 Website Running Slow?

Users complain:

  • Website is slow
  • Application freezes
  • Login page takes forever

The first question isn’t:

“Did hackers attack us?”

The first question is:

“What’s happening on the server?”

⚙ What Is A Process?

A process is simply:

A running program

Examples:

  • Web Server
  • Database
  • SSH Service
  • Monitoring Agent
  • Terminal Session

Every active application creates one or more processes.

🔍 View Running Processes

One of the most common Linux commands:

ps aux

This displays:

  • Running processes
  • Users
  • CPU usage
  • Memory usage

📈 Real-Time Monitoring

View live system activity:

top

Shows:

  • CPU utilization
  • Memory usage
  • Running processes
  • System load

Many administrators start troubleshooting with top.

🔥 Tool Spotlight: htop

Many professionals prefer:

htop

Why?

  • Cleaner interface
  • Easier navigation
  • Colorful resource charts
  • Interactive process management

Think of it as a modern version of top.

🧠 Memory Usage

Check RAM usage:

free -h

The -h means:

Human Readable

Much easier to understand than raw numbers.

💾 Disk Space

Check storage usage:

df -h

Example problems:

  • Disk full
  • Logs consuming storage
  • Applications unable to write files

Disk issues cause many outages.

⏱ System Uptime

Check system availability:

uptime

Shows:

  • System running time
  • Current load
  • Connected users

🚨 Real Investigation Example

Website becomes slow.

Administrator checks:


top

free -h

df -h

Finds:

Disk Usage: 100%

Root cause:

Application logs consumed all available storage.

⚙ System Services

Modern Linux systems use services for:

  • Web Servers
  • Databases
  • SSH Access
  • Monitoring Tools

View service status:

systemctl status ssh

This command is used daily by administrators.

⚡ Health Check Toolkit


ps aux

top

htop

free -h

df -h

uptime

systemctl status

🎯 10-Minute Health Check Lab

ps aux

top

free -h

df -h

uptime

Try identifying:

  • CPU usage
  • Available memory
  • Disk usage
  • System uptime

💼 What Professionals Actually Monitor

  • CPU Utilization
  • Memory Usage
  • Disk Space
  • Application Health
  • Service Availability
  • System Load

Monitoring is one of the most important operational skills.

🏆 Key Lesson

Most outages are not discovered by guessing.

They’re discovered through visibility.

The better you understand system health, the faster you can solve problems.

Visibility Creates Control

NEXT CHAPTER

🌐 Linux Networking Essentials

Learn how Linux connects to networks and discover the commands administrators use daily to troubleshoot connectivity issues.