Frequently Asked Questions

  • What is ReadyKernel?

    ReadyKernel is a kpatch-based service that offers a more convenient, rebootless alternative to updating the kernel the usual way and allows you not to wait for scheduled server downtime to apply critical security updates. 
  • How much does ReadyKernel cost?

    ReadyKernel is free for all paid customers of Virtuozzo.
  • Is there any support for ReadyKernel?

    ReadyKernel is supported by Virtuozzo. You can get support if you have an active subscription to Virtuozzo.
  • Do I have to reboot my server after installing a ReadyKernel patch?

    There is no need to reboot the server after installing any ReadyKernel patches or tools.
  • Which kernels are supported by ReadyKernel?

    The list of supported Virtuozzo kernels is published at
  • Can I check if my server is affected by any CVE fixed with ReadyKernel?

    We suggest you to test your environment with a simple ReadyKernel scanner utility available here: readykernel-scan.
    To scan your server, run # wget; python readykernel-scan
  • Is using ReadyKernel safe?

    ReadyKernel patches will not be installed on and applied to your host if your kernel is incompatible with the patch. Moreover, if ReadyKernel detects that it is unsafe to apply the patch at the moment, the patch will not be applied and the system will remain in its original state.
  • What about regular OS updates?

    ReadyKernel only keeps the kernel secure. User space packages are not affected by ReadyKernel and should be updated the usual way.
  • How can I install ReadyKernel and update the kernel with it?

    The software components required by ReadyKernel are automatically installed together with ReadyKernel updates. To install the latest ReadyKernel update for the currently running kernel, just run: # yum install readykernel-patch-$(uname -r)
  • How can I uninstall ReadyKernel?

    To uninstall ReadyKernel, run # yum remove 'readykernel*' 'kpatch*'
  • How can I enable automatic installation of ReadyKernel updates?

    Add the following command to the cron schedule: /usr/bin/yum install -y readykernel-patch-$(uname -r)
  • How can I list patches applied to the kernel?

    To display information about the currently applied kernel patches, run # readykernel info
  • Is ReadyKernel software released under open source?

    To perform most operations, ReadyKernel uses customized Kpatch tools. The source code is available at under the GPL2 license. Binary patches are a part of the paid service and are not publicly available.