NAVIX 9

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Available in VPC

You can update a kernel on the NAVIX 9 server of NAVER Cloud Platform.

This guide is written based on new servers created on NAVER Cloud Platform, so there might be differences from the user server environment.
User server environments may be affected by kernel updates and server restarts due to various reasons such as security hardening tasks and other setting tasks.
Therefore, be familiar with the following before you perform a kernel update:

  • Create a replicated server using Server image before updating a kernel of the actual server.
    Perform the kernel update on the replicated server and check if it restarts successfully.
    When switching to operational status after restarting, check for any issues in the server.
    Perform the kernel update only after thorough validation to ensure there are no issues.
  • In the case of GPU servers, the GPU driver that matches the kernel version must be installed for normal operation.
    If the updated kernel is incompatible with GPU drivers, the GPU server might not function normally.
    Therefore, check GPU driver compatibility before you perform kernel updates.
    For related information, see GPU driver guide.
Note

This kernel update guide will no longer provide regular updates moving forward.
Therefore, when checking for the latest information or installing a different kernel version, see the relevant guide and take the necessary steps.
The kernel version specified in the guide serves as an example, so make sure to thoroughly test other kernel versions as needed before installation.

Caution
  • The user is solely responsible for performing kernel updates on their server, and NAVER Cloud Platform will not be held responsible for any issues caused by these updates.
  • Normal server usage might be unavailable during kernel updates and restarts, and recovery from this issue is not supported. In addition, server recovery is not supported when the kernel update fails.
  • Before updating the kernel, make sure to keep the backup created through Server image until it is no longer needed.
  • No separate support is provided for problems related to this guide.

Check kernel versions available for update

To check the kernel versions available for update on a NAVIX 9 server:

By default, http://navix.ncloud.com, the NCP repo is set as the base URL. In environments with a public IP or a private subnet configured with NAT, you can switch the repository to an external public mirror site instead of the NCP repo.

Note

NCP repo is a repository provided by NAVER Cloud Platform to support user environments like VPC private subnets where external access is limited.
Since NCP repo synchronizes only 4 times a year, it is recommended to switch to an external public mirror site to apply the latest patches promptly. For more information, see [
OS Repository configuration checklist guide] (/docs/en/linux-os-repository-check).

  1. Access the server you want to apply the kernel update to remotely.
  2. Check the kernel version to apply to the server.
    [root@navix ~]# dnf --showduplicates list kernel
    Installed Packages
    kernel.x86_64                  5.14.0-570.22.1.el9_6                   @updates 
    Available Packages
    kernel.src                     5.14.0-570.12.1.el9_6                   baseos-source 
    kernel.x86_64                  5.14.0-570.12.1.el9_6                   baseos        
    kernel.src                     5.14.0-570.16.1.el9_6                   updates-source
    kernel.x86_64                  5.14.0-570.16.1.el9_6                   updates    
    ... Omitted ...
    

Update kernel

To update kernels for NAVIX 9 servers:

Note

This guide provides an example of upgrading the kernel version to 5.14.0-570.58.1.el9_6 on a NAVIX 9 server.
The kernel versions available for installation at the time of referencing the guide may vary, so thoroughly test other versions before installation.

  1. Access the server you want to apply the kernel update to remotely.

  2. Check the kernel version of the server.

    [root@navix ~]# uname -r
    5.14.0-570.28.1.el9_6
    
  3. Check the repository information connected to the server.
    If you need to edit the Repo file, see Linux OS repository configuration checklist guide to edit the repository information.

    [root@navix ~]# dnf repolist -v | grep -E "Repo-id|Repo-baseurl"
    Repo-id            : appstream
    Repo-baseurl       : http://navix.ncloud.com/pub/9/x86_64/AppStream/os/
    Repo-id            : appstream-source
    Repo-baseurl       : http://navix.ncloud.com/pub/9/x86_64/AppStream/source/tree/
    Repo-id            : baseos
    ... Omitted ...
    Repo-id            : updates
    Repo-baseurl       : http://navix.ncloud.com/pub/9/x86_64/Updates/os/
    Repo-id            : updates-source
    Repo-baseurl       : http://navix.ncloud.com/pub/9/x86_64/Updates/source/tree/ 
    
    
  4. Check the kernel version provided by the repository.

    [root@navix ~]# dnf clean all
    
    [root@navix ~]# dnf list kernel-5.14.0-570.58.1.el9_6 
    Available Packages
    kernel.x86_64                5.14.0-570.58.1.el9_6                @updates 
    
  5. Install the viewed version of the kernel.
    Carefully review the list of packages being newly installed, updated, or removed. If everything is in order, enter y to complete the installation.

    [root@navix ~]# dnf install kernel-5.14.0-570.58.1.el9_6 
    dnf install kernel-5.14.0-570.58.1.el9_6
    Last metadata expiration check: 0:24:39 ago on Wed 19 Nov 2025 03:56:11 AM EST.
    Dependencies resolved.
    ================================================================================
     Package                 Arch       Version                   Repository   Size
    ================================================================================
    Installing:
     kernel                  x86_64     5.14.0-570.58.1.el9_6     updates     1.8 M
    Installing dependencies:
     kernel-core             x86_64     5.14.0-570.58.1.el9_6     updates      18 M
     kernel-modules          x86_64     5.14.0-570.58.1.el9_6     updates      39 M
     kernel-modules-core     x86_64     5.14.0-570.58.1.el9_6     updates      31 M
    
    Transaction Summary
    ================================================================================
    Install  4 Packages
    
    Total download size: 89 M
    Installed size: 132 M
    Is this ok [y/N]: y
    
    ... Omitted ...
    
    Installed:
    kernel-5.14.0-570.58.1.el9_6.x86_64                                           
    kernel-core-5.14.0-570.58.1.el9_6.x86_64                                      
    kernel-modules-5.14.0-570.58.1.el9_6.x86_64                                   
    kernel-modules-core-5.14.0-570.58.1.el9_6.x86_64                              
    
    Complete!
    
  6. After the installation is complete, check the bootable kernel version and the default boot kernel version.

     [root@navix ~]# grep BLSCFG /etc/default/grub
     GRUB_ENABLE_BLSCFG=true
    
     [root@navix ~]# grubby --info=ALL | grep ^kernel
     kernel="/boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64"
     kernel="/boot/vmlinuz-5.14.0-570.55.1.el9_6.x86_64"
     kernel="/boot/vmlinuz-5.14.0-570.28.1.el9_6.x86_64"
     kernel="/boot/vmlinuz-0-rescue-679cfa1a1bd9441bb946eda5b9314e73"
    
     [root@navix ~]# grubby --default-kernel
     /boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64
    
  7. (Optional) If the default boot kernel version is different from the installed kernel version, change the default boot kernel.

    [root@navix ~]# grubby --info=ALL | grep ^kernel
    kernel="/boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-5.14.0-570.55.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-5.14.0-570.28.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-0-rescue-679cfa1a1bd9441bb946eda5b9314e73"
    
    [root@navix ~]# grubby --set-default="/boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64"
    The default is /boot/loader/entries/679cfa1a1bd9441bb946eda5b9314e73-5.14.0-570.58.1.el9_6.x86_64.conf with index 0 and kernel /boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64
    
    [root@navix ~]# grubby --default-kernel
    /boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64
    
  8. Reboot the server to activate the latest kernel version.

    [root@navix ~]# sync;reboot
    
    Note

    If the server reboot fails, it means the kernel update was not successfully applied. In this case, see Restore kernel update to revert to the previous kernel version.

  9. Log in to the server again and check if the new kernel is activated.

    [root@navix ~]# uname -r
    5.14.0-570.58.1.el9_6.x86_64
    
    Note

    To check if the updated kernel is properly applied, see Check kernel update to check the kernel installation status.

Check kernel update

To check if the kernel update was successfully applied:

  1. Access the server remotely.
  2. Check if the kernel package is installed.
    [root@navix ~]# rpm -qa|grep kernel-5.14.0-570.58.1.el9_6.x86_64
    kernel-5.14.0-570.58.1.el9_6.x86_64
    
  3. Check if the initramfs file and vmlinuz file are created in the /boot directory.
    Note

    The /boot/initramfs-.x86_64kdump.img file may not be created depending on your settings.

    [root@navix ~]# ls -l /boot/initramfs-5.14.0-570.58.1.el9_6.x86_64.img 
    -rw-------. 1 root root 36517861 Nov 19 03:50 /boot/initramfs-5.14.0-570.58.1.el9_6.x86_64.img
    
    [root@navix ~]# ls -l /boot/initramfs-5.14.0-503.19.1.el9_5.x86_64kdump.img
    -rw------- 1 root root 31055360 Dec 31 15:18 /boot/initramfs-5.14.0-503.19.1.el9_5.x86_64kdump.img
    
    [root@navix ~]# ls -l /boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64 
    -rwxr-xr-x. 1 root root 14928240 Nov 11 06:39 /boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64
    
  4. Check if the latest kernel settings are registered.
    [root@navix ~]# grubby --info=ALL | grep ^kernel
    kernel="/boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-5.14.0-570.55.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-5.14.0-570.28.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-0-rescue-679cfa1a1bd9441bb946eda5b9314e73"
    
    [root@navix ~]# ls -l /boot/loader/entries
    total 16
    -rw-r--r--. 1 root root 469 Aug  1 04:51 679cfa1a1bd9441bb946eda5b9314e73-0-rescue.conf
    -rw-r--r--. 1 root root 445 Nov 19 03:50 679cfa1a1bd9441bb946eda5b9314e73-5.14.0-570.28.1.el9_6.x86_64.conf
    -rw-r--r--. 1 root root 444 Nov 19 04:21 679cfa1a1bd9441bb946eda5b9314e73-5.14.0-570.55.1.el9_6.x86_64.conf
    -rw-r--r--. 1 root root 444 Nov 19 03:50 679cfa1a1bd9441bb946eda5b9314e73-5.14.0-570.58.1.el9_6.x86_64.conf
    
  5. Check the grub settings.
    [root@navix ~]# grep GRUB_DEFAULT /etc/default/grub
    GRUB_DEFAULT=saved
    
    [root@navix ~]# cat /boot/grub2/grubenv
    # GRUB Environment Block
    # WARNING: Do not edit this file by tools other than grub-editenv!!!
    saved_entry=679cfa1a1bd9441bb946eda5b9314e73-5.14.0-570.58.1.el9_6.x86_64
    menu_auto_hide=1
    boot_success=0
    boot_indeterminate=0
    ... Omitted ...
    
    [root@navix ~]# grubby --default-kernel
    /boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64
    

Restore kernel update

If the server fails to restart properly after a kernel update, you must revert to the previous kernel before the update. You can revert it to one of the many installed kernel versions, and this guide describes how to revert the kernel to the version immediately before the update.

Note

To resolve server restart issues, you can attempt server recovery by entering the Single Mode. For more information on how to run reboot in the Single Mode, see Server recovery guide.

  1. From the NAVER Cloud Platform console's VPC environment, navigate to i_menu > Services > Compute > Server.

  2. Click the Server menu.

  3. Select the server to recover from the server list, and click [Server connection console].

  4. Select the previous version as the booting kernel from the grub booting page and reboot.

    • KVM navix 9 grub booting interface
      kernel-update-kvm-navix.9_console01.png
  5. After booting is complete, check the kernel version of the server.

    [root@navix ~]# uname -r
    5.14.0-570.58.1.el9_6.x86_64
    
  6. Check the kernel version that is currently active.

    [root@navix ~]# grubby --default-kernel
    /boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64
    
    [root@navix ~]# grubby --info=ALL | grep ^kernel
    kernel="/boot/vmlinuz-5.14.0-570.58.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-5.14.0-570.55.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-5.14.0-570.28.1.el9_6.x86_64"
    kernel="/boot/vmlinuz-0-rescue-679cfa1a1bd9441bb946eda5b9314e73"
    
  7. Reset the default kernel version to the previous kernel version when booting.

    [root@navix ~]# grubby --set-default="/boot/vmlinuz-5.14.0-570.28.1.el9_6.x86_64"
    The default is /boot/loader/entries/679cfa1a1bd9441bb946eda5b9314e73-5.14.0-570.28.1.el9_6.x86_64.conf with index 2 and kernel /boot/vmlinuz-5.14.0-570.28.1.el9_6.x86_64
    
    [root@navix ~]# grubby --default-kernel
    /boot/vmlinuz-5.14.0-570.28.1.el9_6.x86_64
    
  8. (Optional) Reboot the server to check whether the server boots up normally with the updated kernel version.

    [root@navix ~]# sync;reboot
    
  9. (Optional) Log back into the server to check the booting status and the kernel version.

    [root@navix ~]# uname -r
    5.14.0-570.28.1.el9_6.x86_64
    

Troubleshoot repository related issues during kernel update

In case of repository issues during a kernel update, see Linux OS Repository configuration checklist guide FAQ.