How To Install Logrotate on Ubuntu 24.04 LTS

In the world of system administration, managing log files is a crucial task that can significantly impact system performance and stability. As your Ubuntu 24.04 LTS server generates logs continuously, it’s essential to have a reliable tool to handle log rotation, compression, and deletion. Enter Logrotate – a powerful utility designed to simplify log management and keep your system running smoothly.

This comprehensive guide will walk you through the process of installing and configuring Logrotate on Ubuntu 24.04 LTS. We’ll cover everything from basic setup to advanced configurations, ensuring you have the knowledge to effectively manage your system’s log files.

Understanding Logrotate

Logrotate is an essential tool for Linux system administrators, designed to manage log files efficiently. Its primary functions include:

• Rotating log files to prevent them from consuming excessive disk space
• Compressing old logs to save storage
• Deleting outdated logs based on specified criteria
• Ensuring that current log files are available for ongoing logging processes

By automating these tasks, Logrotate helps maintain system performance and prevents log-related issues that could potentially disrupt your server’s operations.

Prerequisites

Before we dive into the installation process, ensure that your system meets the following requirements:

• Ubuntu 24.04 LTS installed and updated
• A user account with sudo privileges
• Terminal access to your server

Step-by-Step Installation Guide

1. Update System Packages

Begin by updating your system’s package list to ensure you have the latest information about available packages:

sudo apt update

This step is crucial as it refreshes your system’s knowledge of available packages and their versions, ensuring a smooth installation process.

2. Install Logrotate

Now, let’s install Logrotate using the following command:

sudo apt install logrotate

Ubuntu typically comes with Logrotate pre-installed, but running this command will ensure you have the latest version or install it if it’s missing.

3. Verify Installation

After the installation completes, verify that Logrotate is correctly installed by checking its version:

logrotate --version

This command should display the installed version of Logrotate, confirming a successful installation.

Configuring Logrotate

Logrotate’s configuration is managed through two primary locations:

1. The main configuration file: /etc/logrotate.conf
2. The configuration directory: /etc/logrotate.d/

The main configuration file sets global defaults, while the directory contains specific configurations for individual applications or services.

Understanding the Default Configuration

Let’s examine the default Logrotate configuration. Open the main configuration file:

sudo nano /etc/logrotate.conf

You’ll see various global settings, such as:

# rotate log files weekly
weekly

# keep 4 weeks worth of backlogs
rotate 4

# create new (empty) log files after rotating old ones
create

# use date as a suffix of the rotated file
dateext

# uncomment this if you want your log files compressed
#compress

These settings apply to all log rotations unless overridden in specific configuration files.

Creating a Custom Configuration

To create a custom configuration for a specific application, let’s use a hypothetical example. Suppose you have an application called “myapp” that generates logs in /var/log/myapp/.

Create a new configuration file:

sudo nano /etc/logrotate.d/myapp

Add the following configuration:

/var/log/myapp/*.log {
    daily
    missingok
    rotate 14
    compress
    delaycompress
    notifempty
    create 0640 myapp-user myapp-group
    sharedscripts
    postrotate
        systemctl reload myapp
    endscript
}

This configuration rotates logs daily, keeps 14 old logs, compresses them (with a one-day delay), and reloads the application after rotation.

Advanced Configuration Options

Size-Based Rotation

For applications generating large amounts of logs, size-based rotation can be more appropriate than time-based rotation. Modify your configuration to include size limits:

/var/log/myapp/*.log {
    size 100M
    rotate 5
    compress
    delaycompress
    missingok
    notifempty
    create 0640 myapp-user myapp-group
}

This configuration rotates logs when they reach 100MB, keeping 5 old logs.

Date-Based Naming

To make log files easier to identify, you can use date-based naming:

/var/log/myapp/*.log {
    daily
    dateext
    dateformat -%Y-%m-%d
    rotate 30
    compress
    missingok
    notifempty
}

This appends the date to rotated log files, making it easier to track logs over time.

Copytruncate Option

Some applications don’t handle log file rotation well. The copytruncate option can help in such cases:

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

This option copies the log file and truncates the original, allowing the application to continue writing to the same file descriptor.

Managing Logs Across Multiple Servers

In distributed environments, managing logs across multiple servers can be challenging. Here’s a strategy using Logrotate:

1. Set up a central log server to collect logs from all servers.
2. On each server, configure Logrotate to rotate logs locally and then transfer them to the central server.

Example configuration:

/var/log/myapp/*.log {
    daily
    rotate 3
    compress
    delaycompress
    missingok
    notifempty
    create 0640 myapp-user myapp-group
    postrotate
        rsync -avz /var/log/myapp/ central-log-server:/logs/server1/
    endscript
}

This configuration rotates logs locally and then uses rsync to transfer them to a central server.

Debugging and Troubleshooting

When troubleshooting Logrotate configurations, the following tips can be helpful:

1. Use the Debug Option

Run Logrotate in debug mode to see what it would do without actually rotating logs:

sudo logrotate -d /etc/logrotate.conf

This command provides detailed output about Logrotate’s decision-making process.

2. Check Logrotate’s Status File

Examine Logrotate’s status file to see when logs were last rotated:

sudo cat /var/lib/logrotate/status

3. Force Rotation

To test your configuration, you can force Logrotate to run:

sudo logrotate -f /etc/logrotate.conf

This command forces Logrotate to run, ignoring the usual time-based triggers.

Best Practices for Using Logrotate

To ensure optimal log management with Logrotate, consider the following best practices:

• Regularly review and update your Logrotate configurations to match changing system needs.
• Use appropriate rotation frequencies and retention periods based on the importance and growth rate of each log.
• Implement compression to save disk space, but be mindful of CPU usage during compression.
• Use the delaycompress option when logs might still be in use by applications.
• Implement proper file permissions and ownership for rotated logs to maintain security.
• Use the sharedscripts option when multiple log files share the same post-rotation actions.

Congratulations! You have successfully installed logrotate. Thanks for using this tutorial for installing Logrotate to manage logs on Ubuntu 24.04 LTS system. For additional help or useful information, we recommend you to check the official Logrotate website.