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CentOS Kernel Upgrade

This addendum to the Paragon Insights (formerly HealthBot) Installation Guide is for those who need to upgrade the kernel version of their CentOS 7 server to 4.4.19 to meet the requirements for Paragon Insights installation. Kernel upgrade is required for both single and multinode installation. With Paragon Insights Release 4.0.0, for CentOS 8 server and RHEL 8, kernel upgrade is not required. This document assumes that you are familiar with yum and rpm, the software package management systems on CentOS and Red Hat, as well as the Grub boot manager.

For those who prefer to watch the commands as they are executed:

The kernel upgrade process involves the following steps:

  • Confirm the current kernel version

  • Update existing software packages to the latest versions

  • Install GPG key for ElRepo software repository

  • Install the ElRepo software repository

  • Confirm the latest kernel in ElRepo software repository

  • Install the latest kernel

  • Reboot to load new kernel

  • Verify that the system is running on the new kernel

  • Edit Grub configuration

  • Install Grub configuration

  • Reboot

To perform a kernel upgrade, you must be logged in to your server as the root user or be able to obtain root privileges using the sudo su command. The commands in the rest of the procedure assume that you are logged in as root or have issued the sudo -s command.


Confirm the Current Kernel Version

Since the existing kernel is below the required version, we must upgrade the kernel on this server.

Begin the kernel upgrade procedure by updating the yum repositories and installed software packages.

To update yum repositories and installed software packages:

  • Update Existing Software Packages to the Latest Versions

    If you examine the output above, you’ll see that 19 packages were upgraded and a new kernel with the same major release number (3) as the existing kernel was installed.

CentOS does not provide the latest available kernel versions in its software repository. Therefore, the ElRepo (elrepo) software repository is used. Additionally, CentOS requires all software to be signed; so you must install the elrepo GPG signature key before installing the elrepo repository.

Installing the elrepo GPG signature key requires a single rpm command which returns no output if successful:

  • Install GPG Key for ElRepo Software Repository

  • Install ElRepo Software Repository

  • Confirm the Latest Kernel in the ElRepo Repository

    Notice the names of the available kernels and tools in the output. The exact versions available will likely differ from what is shown in the example above. The -lt kernels (and tools) are stable, long-term kernels. The -ml kernels (and tools) are mainline release kernels with shorter support terms but more frequent releases.

    Best Practice:

    We recommend using a -lt releases for stability.

After reboot, confirm the running kernel.

  • Install Latest Kernel

  • Reboot to Load New Kernel

    We do not show the output from the reboot command.

  • Verify New Kernel

  • Edit Grub Configuration

    We don’t know exactly how Grub is configured on your server. The following procedure is, therefore, generic. The goal is to have the boot loader (grub) use the new kernel whenever you reboot. Since the previous steps put the new kernel at the top of the list of kernels, in position 0 (zero); we configure grub to use the kernel listed in that position by default.

    Use the text editor of your choice to edit the file: /etc/default/grub. (Editors include vi, nano, and emacs.)

    Change the line that says:

    To:

    Save the file.

The edited grub configuration needs to be installed so that the server will use it at boot time.

  • Install Grub Configuration

The new kernel is now operational. The last step is to confirm that grub uses the new kernel at reboot.

Related Documentation