Linux logrotate Guide

Linux logrotate Guide

Complete beginner-friendly guide to logrotate on Linux, covering Arch Linux, CachyOS, and other distributions including log rotation, configuration, and log management.

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Table of Contents

1. Understanding logrotate
2. logrotate Installation
3. Configuration
4. Creating Rules
5. Testing
6. Troubleshooting

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Understanding logrotate

What is logrotate?

logrotate rotates, compresses, and manages log files.

Functions:

• Prevent disk full: Rotate logs before they grow too large
• Compress logs: Save disk space
• Archive logs: Keep old logs for reference
• Delete old logs: Remove logs after retention period

Why it matters:

• Disk space: Prevents logs from filling disk
• Organization: Keeps logs manageable
• Compliance: Maintains log history

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logrotate Installation

Install logrotate

Arch/CachyOS:

# Install logrotate
sudo pacman -S logrotate

# Enable service (if using systemd)
sudo systemctl enable logrotate.timer

Debian/Ubuntu:

sudo apt install logrotate

Fedora:

sudo dnf install logrotate

Verify Installation

Check logrotate:

# Check version
logrotate --version

# Check status
systemctl status logrotate.timer

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Configuration

Main Configuration

Edit config:

# Main config
sudo vim /etc/logrotate.conf

Common settings:

# Rotate weekly
weekly

# Keep 4 weeks of logs
rotate 4

# Create new empty log
create

# Compress old logs
compress

# Delay compression
delaycompress

Configuration Directory

Per-application configs:

# Application configs
/etc/logrotate.d/

# List configs
ls /etc/logrotate.d/

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Creating Rules

Basic Rule

Create rule:

# Create rule file
sudo vim /etc/logrotate.d/myapp

Basic rule:

/var/log/myapp.log {
    daily
    rotate 7
    compress
    missingok
    notifempty
}

Advanced Rule

Advanced options:

/var/log/myapp/*.log {
    daily
    rotate 30
    compress
    delaycompress
    missingok
    notifempty
    create 0640 user group
    sharedscripts
    postrotate
        /usr/bin/systemctl reload myapp
    endscript
}

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Testing

Test Configuration

Test logrotate:

# Test configuration
sudo logrotate -d /etc/logrotate.conf

# Test specific config
sudo logrotate -d /etc/logrotate.d/myapp

# Force rotation (dry run)
sudo logrotate -f /etc/logrotate.conf

Manual Rotation

Rotate manually:

# Force rotation
sudo logrotate -f /etc/logrotate.d/myapp

# Verbose output
sudo logrotate -v /etc/logrotate.d/myapp

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Troubleshooting

Logs Not Rotating

Check configuration:

# Test config
sudo logrotate -d /etc/logrotate.conf

# Check for errors
sudo logrotate -v /etc/logrotate.conf

# Check state file
cat /var/lib/logrotate/status

Permission Issues

Fix permissions:

# Check log file permissions
ls -la /var/log/myapp.log

# Fix ownership
sudo chown user:group /var/log/myapp.log

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Summary

This guide covered logrotate installation, configuration, and log management for Arch Linux, CachyOS, and other distributions.

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Next Steps

• Log Management - System logs
• System Monitoring - System monitoring
• System Configuration - System setup
• logrotate Documentation: man logrotate

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This guide covers Arch Linux, CachyOS, and other Linux distributions. For distribution-specific details, refer to your distribution's documentation.