CentOS 7.9 Kernel Upgrade Guide

Upgrading your CentOS Linux release 7.9 to the latest long-term support kernel can enhance your system’s security, stability, and performance. Here’s a step-by-step guide to help you through the process.

🛑 Prerequisites

Before proceeding, ensure that you:

• Are logged in as a user with sudo privileges.
• Have a backup of important data.
• Understand thatIt seems the message was cut off. I’ll provide the conversion of the updated content into HTML starting from the point where the prerequisites are explained:
  • Are logged in as a user with sudo privileges.
  • Have a backup of important data.
  • Understand that upgrading the kernel can be risky, and it’s essential to follow the steps carefully.

  📦 Step 1: Check Your Current Kernel Version

  To see which kernel version you are currently running, use the following command:

  uname -r

  This command will display your current kernel version. Make a note of this in case you need to revert back to it.

  🔄 Step 2: Enable ELRepo Repository

  ELRepo is a repository that focuses on hardware-related packages. It’s a good source for stable kernel updates.

  1. Import the ELRepo public key:

  sudo rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

  2. Install the ELRepo repository:

  sudo yum install https://www.elrepo.org/elrepo-release-7.el7.elrepo.noarch.rpm

  🆕 Step 3: Install the New Kernel

  Option 1: Install the Latest Mainline Kernel

  1. List available kernels:

  yum --disablerepo="*" --enablerepo="elrepo-kernel" list available

  2. Install the latest mainline kernel:

  sudo yum --enablerepo=elrepo-kernel install kernel-ml

  Option 2: Install the Latest Long-Term Support Kernel

  1. List available LTS kernels:

  yum --disablerepo="*" --enablerepo="elrepo-kernel" list available | grep lt

  2. Install the latest LTS kernel:

  sudo yum --enablerepo=elrepo-kernel install kernel-lt

  ⚙️ Step 4: Update the GRUB Configuration

  1. Check the GRUB menu entries:

  Use the provided command to list all the GRUB menu entries:

  awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg

  Look for the entry that corresponds to the newly installed kernel.

  2. Set the default GRUB entry:

  If the latest kernel is at the top of the list, you can set it as the default by using:

  sudo grub2-set-default 0

  If it’s not the first entry, replace 0 with the appropriate number corresponding to the new kernel’s position.

  🔁 Step 5: Reboot and Verify

  1. Reboot your system:

  sudo reboot

  2. Verify the new kernel:

  Once your system reboots, log in and execute the following command:

  uname -r

  This should display the version of the kernel that you installed, whether it’s the mainline or the LTS version.

  🛡 Step 6: Final Checks

  After the upgrade, it’s crucial to:

  • Check that all services are running as expected.
  • Monitor the system for any unusual behavior.

  Congratulations! 🎉 You have successfully upgraded your CentOS 7.9 kernel to the latest long-term support version.