Arch Linux systemd Advanced Guide

Complete beginner-friendly guide to advanced systemd usage on Arch Linux, including unit files, timers, targets, and systemd customization.

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Table of Contents

1. Unit Files
2. Creating Services
3. Timers
4. Targets
5. Troubleshooting

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Unit Files

Understanding Units

Unit types:

• service: System services
• timer: Scheduled tasks
• target: System states
• mount: Filesystem mounts
• socket: Network sockets

Unit Locations

Unit directories:

# System units
/etc/systemd/system/

# User units
~/.config/systemd/user/

# Runtime units
/run/systemd/system/

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Creating Services

Create Service

Create service file:

# Create service
sudo vim /etc/systemd/system/myservice.service

Example:

[Unit]
Description=My Service
After=network.target

[Service]
Type=simple
ExecStart=/usr/bin/mycommand
Restart=always

[Install]
WantedBy=multi-user.target

Enable Service

Enable service:

# Reload systemd
sudo systemctl daemon-reload

# Enable service
sudo systemctl enable myservice

# Start service
sudo systemctl start myservice

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⏰ Timers

Create Timer

Create timer:

# Create timer
sudo vim /etc/systemd/system/mytimer.timer

Example:

[Unit]
Description=My Timer

[Timer]
OnCalendar=daily
Persistent=true

[Install]
WantedBy=timers.target

Enable Timer

Enable timer:

# Enable timer
sudo systemctl enable mytimer.timer

# Start timer
sudo systemctl start mytimer.timer

# Check status
systemctl status mytimer.timer

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Targets

Understanding Targets

Common targets:

• multi-user.target: Multi-user mode
• graphical.target: GUI mode
• rescue.target: Rescue mode
• emergency.target: Emergency mode

Change Target

Switch target:

# Change target
sudo systemctl set-default multi-user.target

# Or
sudo systemctl isolate multi-user.target

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Troubleshooting

Service Not Starting

Check logs:

# Service logs
journalctl -u service-name

# Recent logs
journalctl -u service-name -n 50

# Follow logs
journalctl -u service-name -f

Unit Errors

Check unit:

# Check unit
systemctl status service-name

# Validate unit file
systemd-analyze verify /etc/systemd/system/service.service

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Summary

This guide covered unit files, creating services, timers, targets, and troubleshooting.

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Next Steps

• Systemctl Troubleshooting - More on systemctl
• Arch Linux System Configuration - System setup
• ArchWiki systemd: https://wiki.archlinux.org/title/Systemd

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This guide is based on the ArchWiki. For the most up-to-date information, always refer to the official ArchWiki.