CageFS can’t start – Error: current running kernel is NOT supported March 20, 2025

In this guide, we will explain how to Fix CageFS Startup Error: Unsupported Kernel.

Fix the CageFS initialisation error to ensure the system uses a supported kernel, allowing CageFS to function properly and enhance server security.

Issue:
If initialisation fails due to an unsupported kernel, you will see the following error:
# /usr/sbin/cagefsctl –init

Error: current running kernel is NOT supported

Environment:

• CloudLinux 7
• CloudLinux 8
• CageFS

Solution:

1. Verify the Running Kernel
   Ensure the server is using the CloudLinux kernel (lve should be present in its name):

   # uname -r

   Example of a correct CloudLinux kernel:
   4.18.0-305.12.1.lve.el8.x86_64
   When the system runs CentOS or another OS kernel, update the default entry in the GRUB bootloader and reboot the server.

2. Check & Install kmod-lve Module:
   1. Verify kmod-lve Installation

      # rpm -q kmod-lve
      # lsmod | grep kmodlve

   2. Install kmod-lve If Missing

      # yum install kmod-lve

      Manually load the module:

      # modprobe kmodlve

      Confirm installation:

      # lsmod | grep kmodlve

   3. Ensure kmod-lve Loads Automatically
      1. Check for Blocklisting

         # grep lve /etc/modprobe.d/*
         # grep black /etc/modprobe.d/*

      2. Verify & Update Grub Configuration
         First, remove systemd.unified_cgroup_hierarchy=1 from /etc/default/grub and then rebuild Grub:

         # grub2-mkconfig -o /boot/grub2/grub.cfg

      3. Confirm Modules Are Enabled in sysctl

         # sysctl -a | grep kernel.modules_disabled

         Ensure the value is set to 0.

      4. Verify Package Integrity

         # rpm -V liblve-devel liblve

   4. Unmask & Start LVE Services
      If you find LVE services masked, unmask and start them:

      # systemctl unmask lvectl.service
      # systemctl unmask lve.service
      # systemctl unmask lve_namespaces.service
      # systemctl unmask lvestats.service
      # systemctl start lvectl
      # systemctl start lve.service
      # systemctl start lve_namespaces.service
      # systemctl start lvestats.service

Cause:
Failure to load the LVE module prevents CageFS from initialising properly.

That is it! Hope you liked our article. If you require any additional help, feel free to reach out to our support team.

Need to manage CageFS for users? Learn How to enable or disable CageFS for users in CloudLinux