KernelCare error: "Unknown Kernel"

Synopsis

The "Unknown Kernel" or "Unsupported Kernel" messages are somewhat common. In this article, we aim to help troubleshoot this error further.

First of all, run the following script to check your kernel's compatibility with KernelCare:

curl -s -L https://kernelcare.com/checker | python

Troubleshooting

Check what output do you get and follow the steps below.

Compatible

If the checker script shows the "Compatible" output, KernelCare does support your system. There may be some caveats with much older or newest kernels, but we'll get to that a bit later.

Make sure that you use the latest KernelCare release. Update the package via your package manager (the example below is for RHEL-based systems):

yum update kernelcare 
kcarectl --update

The Unknown Kernel message should be gone by now. If it doesn't, it means that KernelCare doesn't recognize the kernel you're using. You either use the newest kernel or you use an operating system release that is completely not supported by KernelCare. Please check your OS type/release, and your kernel's version:

cat /etc/*-release
uname -r

Go to https://patches.kernelcare.com/ and check if your OS is supported (select your OS from the drop-down list) and your kernel version.

If your kernel version is older than the ones we have on the Patches page, you need to update the kernel to the version that we support and reboot the server just this once. 

If your kernel version is the newest, chances are we haven't added the support for it just yet. Usually, we add KC support for the new kernels within 3-4 days since its release. Since the new kernels have no vulnerabilities (and if they do, we'll speed things up on our end), it's safe to ignore the "Unknown Kernel" message. If you wish, you may add the following line to your /etc/sysconfig/kcare/kcare.conf file:

IGNORE_UNKNOWN_KERNEL=True

Note: IGNORE_UNKNOWN_KERNEL works only when the kcarectl run with --auto-update option.

Unsupported

KernelCare doesn't recognize the kernel. It means that you either use the newest kernel or you use an operating system release that is completely not supported by KernelCare. Please check your OS type/release here:

https://patches.kernelcare.com/

If you find your OS in the KernelCare compatible list, check the "Compatible" instructions above.

If you don't see your OS in the list, it is not possible to use KernelCare on the server. Please stay tuned to our blog to be notified when we add new supported OS.

 

Unsupported; Inside Container

KernelCare is running inside the container, it is unable to patch the kernel. You should install and use KernelCare on your node server, not inside the container.

If you have any doubts, you can contact our support team to double-check.