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Ensuring compatibility with a new kernel version

Robert Stegmann

After successfully installing a cPanel on a fresh Ubuntu Server 22.04 LTS (Jammy Jellyfish), I got the following warning

[2025-08-29 17:06:37 +0000] [32843] ( WARN): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[2025-08-29 17:06:37 +0000] [32843] ( WARN): Your system kernel may have been updated.
[2025-08-29 17:06:37 +0000] [32843] ( WARN): Current kernel (5.15.0-151-generic) has been changed to: 5.15.0-153-generic
[2025-08-29 17:06:37 +0000] [32843] ( WARN): Before rebooting the system, please ensure that the installed kernel version is compatible with your deployment.
[2025-08-29 17:06:37 +0000] [32843] ( WARN): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I am 90% sure that this new kernel shouldn't cause any issues since it is for Ubuntu 22.04, but other users have had issues after having their kernel updated. How am I to determine that the new kernel version is compatible with my deployment? Or is this question for the server provider?

Comments

2 comments

Date Votes
  • cPRex Jurassic Moderator

    Hey there!  That's a standard warning that will show up every time the kernel is updated.  On the cPanel side of things, we don't care, but it's just warning you that if you have any customizations to the OS itself that you should check for compatibility before the reboot.

    If you haven't done anything out of the ordinary with the OS, it will almost certainly be fine.

    0
  • Rubfy

    Short answer: that warning is generic. Minor 5.15 → 5.15 kernel bumps on Ubuntu 22.04 are normally safe for cPanel. The only risk is if you use out-of-tree modules (DKMS, custom RAID/NIC/GPU, ZFS, etc.). Here’s a quick pre-reboot checklist:

    1) Confirm current vs new kernel

     
    uname -r # current (e.g. 5.15.0-151-generic) ls -1 /boot/vmlinuz-* | tail -n2 # verify 5.15.0-153-generic is installed

    2) DKMS/out-of-tree modules build for the new kernel

     
    dkms status || echo "No DKMS modules installed" # If you see modules listed, prebuild them for the new kernel: sudo dkms autoinstall -k 5.15.0-153-generic

    3) Virt/network/storage drivers look sane (optional sanity)

     
    lsmod | egrep 'virtio|ena|ixgbe|bnx2x|vmxnet3|hv_|megaraid|zfs' || true

    4) Keep a fallback kernel installed
    Make sure the previous kernel (…151) stays installed so you can boot it from Advanced options if needed:

     
    sudo update-grub

    5) Reboot with a rollback plan

    • Reboot in a maintenance window with console access (IPMI/KVM/VM console).

    • If something breaks, select the previous kernel from GRUB, or:

     
    sudo grub-set-default "Advanced options for Ubuntu>Ubuntu, with Linux 5.15.0-151-generic" sudo reboot

    If you haven’t added unusual OS customizations, it will almost certainly be fine. If your provider uses a custom kernel or secure-boot policies, it’s worth confirming with them; otherwise the stock Ubuntu kernel is supported.

    0

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