How to Check the Kernel Version in Linux

The Linux kernel is the heart of any Linux-based operating system. It’s responsible for managing hardware resources, system processes, and facilitating communication between software and hardware components. When working with Linux, especially in system administration, development, or troubleshooting, it’s essential to know the kernel version. Understanding which version of the kernel your system is running can help ensure compatibility with software, access the latest features, and apply necessary security patches.

In this blog post, we will cover various methods to check the kernel version in Linux and explain why it might be necessary to do so.

Why Check the Kernel Version?

Knowing your Linux kernel version can be useful for several reasons:

1. Compatibility: Certain software and drivers may require specific kernel versions to function properly.
2. Security: Older kernels may contain security vulnerabilities. Checking the version helps to verify if your system is up-to-date.
3. Troubleshooting: When diagnosing issues, knowing the exact kernel version can help identify bugs or compatibility problems.

Methods to Check the Kernel Version in Linux

There are several ways to check the kernel version in Linux, and we’ll explore the most commonly used methods.

1. Using the uname Command

The uname command is the most straightforward and widely used method to check the kernel version. It displays basic system information, including the kernel version.

• Step 1: Open your terminal.
• Step 2: Type the following command and press Enter:

      

   

  uname -r

  


   

  This command will display only the kernel version, such as 5.15.0-25-generic.

Explanation:

• 5.15.0 is the kernel version number.
• 25-generic is the specific build of the kernel.

To get more detailed information about the system, including the kernel version, you can use:

This will display a line of text with information about the kernel version, system architecture, and more, for example:

2. Using the /proc/version File

Linux stores information about the kernel and other system details in the /proc directory. The /proc/version file contains information about the kernel version.

• Step 1: Open your terminal.
• Step 2: Type the following command and press Enter:

   

  cat /proc/version

  


  

  The output will be similar to:

   

  Linux version 5.15.0-25-generic (buildd@lcy02-amd64-035) (gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0, GNU ld (GNU Binutils for Ubuntu) 2.38) #25-Ubuntu SMP Thu Apr 14 12:00:00 UTC 2022

  


This method provides more detailed information, including the compiler used to build the kernel and the exact time the kernel was built.

3. Using the hostnamectl Command

The hostnamectl command is typically used to view or set the system’s hostname, but it also provides information about the kernel version.

• Step 1: Open your terminal.
• Step 2: Type the following command and press Enter:

   

  hostnamectl

  


  

  The output will include the kernel version along with other system information:

   

  Static hostname: mylinux

  Icon name: computer-vm

  Chassis: vm

  Operating System: Ubuntu 22.04 LTS

  Kernel: Linux 5.15.0-25-generic

  Architecture: x86-64

  


This is a convenient way to get a quick overview of your system, including the kernel version.

4. Using the dmesg Command

The dmesg command is used to print the kernel ring buffer, which contains messages related to the kernel’s activity. You can use this command to find the kernel version.

• Step 1: Open your terminal.
• Step 2: Type the following command and press Enter:

   

  dmesg | grep "Linux version"

  


  

  This will output the kernel version information from the kernel ring buffer.

5. Using the lsb_release Command (For Ubuntu/Debian-based Distros)

The lsb_release command is used to print distribution-specific information. While it primarily provides information about the Linux distribution, it also mentions the kernel version.

• Step 1: Open your terminal.
• Step 2: Type the following command and press Enter:

   

  lsb_release -a

  


  

  Although this command focuses on distribution details, it can be combined with the uname -r command for a complete system overview.

When Should You Check the Kernel Version?

Here are a few scenarios where knowing the kernel version is particularly useful:

1. After a Kernel Update: After installing a kernel update, it’s a good practice to check if the system is running the updated kernel.
2. Before Installing Drivers: Some drivers require specific kernel versions to function correctly.
3. During Troubleshooting: When facing system issues, the kernel version may help identify bugs or compatibility issues.

Conclusion

Checking the kernel version is a critical task for system administrators, developers, and even casual Linux users. The Linux kernel version provides insight into system security, compatibility, and available features. Whether you use the uname command, explore the /proc/version file, or prefer using hostnamectl, the kernel version is only a command away.

By understanding the different methods to retrieve this information, you are better equipped to manage, troubleshoot, and optimize your Linux system.

How to Check the Kernel Version in Linux (F.A.Q)