Free course

Linux Server Troubleshooting Course

Diagnose Linux server failures with a repeatable method across services, logs, CPU, memory, storage, processes, networking, and recent changes.

5 modules · 25 lessons · No signup

Prerequisites: Shell Commands, Linux Basics and Networking Foundations

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What you'll learn

Collect evidence, isolate the first failing boundary, restore service safely, and leave a useful incident record.

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Course contents

  1. Method and evidence

    Define the symptom, preserve facts, build a timeline, and test one hypothesis at a time.

    1. ✓ Define the symptom and scope
    2. ✓ Preserve state before changing it
    3. ✓ Build a timeline
    4. ✓ Test one hypothesis at a time
    5. ✓ Check your understanding: method and evidence

  2. Services and processes

    Diagnose failed units, process state, signals, file descriptors, and application logs.

    1. ✓ Diagnose a failed unit
    2. ✓ Read process state and relationships
    3. ✓ Use signals deliberately
    4. ✓ Find file descriptor problems
    5. ✓ Check your understanding: services and processes

  3. CPU, memory, and storage

    Interpret load, CPU pressure, memory, swap, I/O, filesystem, and kernel evidence.

    1. ✓ Interpret load and CPU
    2. ✓ Diagnose memory pressure
    3. ✓ Diagnose storage latency
    4. ✓ Read filesystem and kernel evidence
    5. ✓ Check your understanding: cpu, memory, and storage

  4. Network and time

    Test names, routes, sockets, firewalls, packets, TLS, and clock synchronization.

    1. ✓ Test the network in layers
    2. ✓ Inspect listeners and firewalls
    3. ✓ Capture a focused packet trace
    4. ✓ Check time, TLS, and certificates
    5. ✓ Check your understanding: network and time

  5. Recover and prevent

    Roll back safely, verify recovery, improve observability, and write a useful review.

    1. ✓ Choose mitigation before root cause
    2. ✓ Verify recovery from the outside
    3. ✓ Add useful observability
    4. ✓ Write the incident review
    5. ✓ Check your understanding: recover and prevent