🐧Linux System Monitoring Labs

🎯 Objective

Learn how to monitor a Linux system’s performance and resource usage using built-in and common open-source tools.

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🧰 Prerequisites

• Ubuntu 20.04+ system (VM or physical)

• sudo access

Install essential tools

sudo apt update
sudo apt install htop iotop sysstat net-tools dstat -y

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🔹 Lab 1: Monitor CPU and Memory Usage with top and htop

top

✅ Shows real-time CPU, memory, and process usage.

htop

✅ A more interactive and colorful view.

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🔹 Lab 2: Monitor Disk I/O with iotop

sudo iotop

✅ Shows which processes are reading from or writing to the disk.

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🔹 Lab 3: Monitor Disk Usage with df and du

df -h

✅ View disk usage by filesystem.

sudo du -sh /var/*

✅ See which directories are using the most space.

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🔹 Lab 4: Monitor Network Usage with netstat and ss

netstat -tulnp

✅ Shows listening ports and the associated processes.

ss -tulnp

✅ Modern, faster alternative to netstat.

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🔹 Lab 5: Monitor System Load and Performance Over Time

uptime

✅ Displays system load averages.

sar --help
Usage: sar [ options ] [ <interval> [ <count> ] ]

sar -u 1 3

✅ CPU usage history (requires sysstat).

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🔹 Lab 6: Monitor System Resources with dstat

dstat -cdngyt

✅ Combines CPU, disk, net, paging, and I/O stats in one view.

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🔹 Lab 7: Identify High Resource Processes

ps aux --sort=-%cpu | head
ps aux --sort=-%mem | head

✅ Find top CPU and memory-consuming processes.

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✅ Wrap-Up

• ✅ Used top, htop, iotop, dstat for real-time monitoring

• ✅ Monitored CPU, disk, memory, network, and load

• ✅ Learned to investigate and troubleshoot resource hogs

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