How to disable nested virtualization?

Diagnostics

1. Connect to the cluster node via SSH.

2. Check whether nested virtualization is enabled:

   cat /sys/module/kvm_*/parameters/nested

    Examples of responses:

   • "Y", "1" — nested virtualization is enabled;
   • "N", "0" — nested virtualization is disabled.

Solution

To disable nested virtualization before the cluster node reboots:

1. Connect to the cluster node via SSH.
2. Run the commands:
   

   • for Intel CPU: 

     modprobe -r kvm_intel

     modprobe kvm_intel nested=0

   • for AMD CPU: 

     modprobe -r kvm_amd

     modprobe kvm_amd nested=0

To completely disable nested virtualization:

1. Connect to the cluster node via SSH.
2. Specify the following in the /etc/modprobe.d/kvm.conf configuration file:
   

   • for Intel CPU:

     options kvm_intel nested=0

   • for AMD CPU:

     options kvm_amd nested=0