Project 4: Automated Backup System with Timers

A complete backup solution using systemd timers: daily incremental backups, weekly full backups, log rotation, email notifications on failure, and a CLI to check backup status.

Quick Reference

Attribute Value
Primary Language Bash
Alternative Languages Python
Difficulty Level 1: Beginner
Time Estimate Weekend
Knowledge Area System Administration
Tooling Systemd Timers
Prerequisites Basic shell scripting, familiarity with rsync or tar

What You Will Build

A complete backup solution using systemd timers: daily incremental backups, weekly full backups, log rotation, email notifications on failure, and a CLI to check backup status.

Why It Matters

This project builds core skills that appear repeatedly in real-world systems and tooling.

Core Challenges

  • Writing .timer units with OnCalendar expressions (maps to timer scheduling)
  • Making timers persistent so missed runs execute on boot (maps to Persistent=true)
  • Configuring OnFailure= to trigger notification services (maps to failure handling)
  • Using systemd-analyze to verify timer scheduling (maps to debugging tools)
  • Implementing RandomizedDelaySec to avoid thundering herd (maps to production patterns)

Key Concepts

  • Timer units: `man systemd.timer`, systemd.time(7) for calendar syntax
  • Backup strategies: “The Linux Command Line” Ch. 18 by William Shotts
  • Shell scripting for backups: “Wicked Cool Shell Scripts” by Taylor & Perry

Real-World Outcome

Deliver a working demo with observable output that proves the feature is correct.

Implementation Guide

  1. Reproduce the simplest happy-path scenario.
  2. Build the smallest working version of the core feature.
  3. Add input validation and error handling.
  4. Add instrumentation/logging to confirm behavior.
  5. Refactor into clean modules with tests.

Milestones

  • Milestone 1: Minimal working program that runs end-to-end.
  • Milestone 2: Correct outputs for typical inputs.
  • Milestone 3: Robust handling of edge cases.
  • Milestone 4: Clean structure and documented usage.

Validation Checklist

  • Output matches the real-world outcome example
  • Handles invalid inputs safely
  • Provides clear errors and exit codes
  • Repeatable results across runs

References

  • Main guide: SYSTEMD_LEARNING_PROJECTS.md
  • “The Linux Command Line” by William Shotts