How to Check the Kernel Version in Ubuntu: Complete Guide for Beginners and Advanced Users

1. Introduction

Ubuntu is a widely used open-source operating system among Linux distributions. One of the essential components that significantly affects system stability, security, and performance is the kernel. The kernel is the core of the OS and acts as a central component that communicates directly between hardware and software, influencing the operation of the entire system. Therefore, checking the kernel version is crucial for Ubuntu users.

In many situations, such as troubleshooting, enhancing security, or improving performance, knowing the kernel version becomes highly useful. Since kernel security updates are released regularly, it is recommended to keep track of whether the latest version is applied.

This guide introduces multiple methods to check the kernel version in Ubuntu. From terminal-based commands to graphical user interface (GUI) options, we cover a wide range of approaches while also explaining basic kernel concepts and key points.

2. What Is the Kernel?

In Ubuntu and other Linux distributions, the kernel functions as the core of the system. It serves as the nucleus of the OS, enabling communication between hardware and software. This section explains the kernel’s specific roles and highlights its importance.

Roles of the Kernel

The kernel plays several critical roles as a bridge between hardware and software, including:

• Resource Management
  The kernel manages system resources such as the CPU, memory, and disks, ensuring applications can access them appropriately. It enables multiple processes to run simultaneously while maintaining smooth system operation.
• Device Management
  The kernel controls hardware devices such as printers, keyboards, mice, and network cards, allowing applications to interact with them. It manages input and output through device drivers.
• Security and Protection
  The kernel provides security by separating user space and kernel space. This prevents regular applications from directly accessing hardware, ensuring system stability and safety.

The Importance of the Kernel in Ubuntu

In Ubuntu and similar Linux systems, kernel updates not only improve system stability but also enhance security. When vulnerabilities are discovered, the Ubuntu development team promptly releases updates. Thus, regularly checking the kernel version and updating when necessary is essential.

As a core component that affects the entire system, understanding the kernel is vital. The next section explains how to check the kernel version in Ubuntu.

3. How to Check the Kernel Version

There are several ways to check the kernel version in Ubuntu. This section explains easy terminal-based methods and the meaning of the displayed results.

Check with the uname Command

The most common and simple way is to use the uname command, which displays system information, including the kernel version.

1. Open the terminal.
2. Enter the following command and press Enter.

uname -r

• The -r option displays the kernel release version. Example Output:

5.4.0-66-generic

In this example, 5.4.0-66-generic is the kernel version. The version consists of a major version, minor version, and patch number.

Check via the /proc/version File

You can also check the kernel version using the /proc/version file, which includes kernel version details and compilation information.

1. Run the following command in the terminal:

cat /proc/version

Example Output:

Linux version 5.4.0-66-generic (buildd@lcy01-amd64-025) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #74-Ubuntu SMP Thu Jan 14 18:28:23 UTC 2021

Check with the hostnamectl Command

On Ubuntu 16.04 and later, you can use hostnamectl to display system information, including the kernel version.

1. Run the following command in the terminal:

hostnamectl

Example Output:

Static hostname: ubuntu
      Operating System: Ubuntu 20.04.1 LTS
               Kernel: Linux 5.4.0-66-generic
        Architecture: x86-64

Differences Between Each Method

• uname -r: Best for quickly checking the kernel version only.
• /proc/version: Useful for detailed information.
• hostnamectl: Provides overall system info along with the kernel version.

Next, we explain GUI-based options for users unfamiliar with terminal commands.

4. Checking the Kernel Version Using the GUI

Ubuntu provides a simple GUI method to check the kernel version without using commands. This is ideal for beginners.

Using the System Settings Tool

1. Open the Settings menu

• Click the system icon on the desktop and select “Settings”.

1. Navigate to the “About” section

• Open the “About” or “Details” page depending on the Ubuntu version.

1. Check the system information

• The kernel version appears under “Kernel” or “Linux version”. Example:

Linux 5.4.0-66-generic

Using GNOME System Monitor

• Open “System Monitor” from the application menu and check the kernel version in the System tab.

Benefits of GUI-based Checking

GUI methods are intuitive, require no command input, and provide system details visually—ideal for users uncomfortable with the terminal.

5. Understanding Kernel Version Numbers

A kernel version consists of several identifiers. Understanding them helps users recognize update significance.

Version Structure

5.4.0-66-generic

1. Major Version (5) — Indicates major functional changes.
2. Minor Version (4) — Represents improvements or enhancements.
3. Patch Level (0) — Bug fixes and security patches.
4. Build Number (66) — Distribution-specific versioning.
5. Suffix (generic) — Indicates kernel build type.

Benefits of Understanding Kernel Versions

Knowing the meaning of each version component assists with compatibility checks and update decisions.

6. Kernel Versions and Ubuntu Releases

Each Ubuntu release includes a recommended kernel version. Understanding this pairing helps with upgrades and troubleshooting.

LTS Releases and Kernel Versions

LTS versions prioritize stability and long-term security over cutting-edge features.

Understanding Release Kernel Policies

Regular releases use newer kernels and offer shorter support cycles than LTS editions.

7. How to Update the Kernel

Updating the kernel improves performance, hardware support, and security.

Update Benefits

• Security Enhancements
• New Feature Support
• Bug Fixes and Performance Improvements

Update Procedure

1. Update Package Lists

sudo apt update
sudo apt upgrade

2. Install a Specific Kernel Version

sudo apt install linux-image-<version>-generic

3. Reboot the System

sudo reboot

Precautions

• Check Compatibility
• Back Up Important Data
• Keep Older Kernels for Recovery

8. Conclusion

This article explained how to check kernel versions in Ubuntu, understand version components, compare them with Ubuntu releases, and safely perform updates. The kernel is a fundamental system element, and managing it properly maximizes system stability and security.

• Importance of Kernel Awareness
• Multiple Methods to Check Versions
• Understanding Version Structures
• Safe Update Practices

By regularly checking and updating kernel versions, Ubuntu users can maintain optimal performance and security. We hope this guide helps you manage your system more effectively.