"Failed to get cgroup backend" error

Problem

The libvirt error occurs when trying to create a VM:

failed to get cgroup backend for 'setCpusetMemoryMigrate' controller '2'

The error occurs due to issues in QEMU's interaction with cgroups (control groups) — a Linux kernel feature for limiting and managing resources (CPU, memory, disk, network) for processes.

Solution

To solve the problem:

1. Connect to the cluster node via SSH. For more information about connecting via SSH, see Workstation setup.
2. Add or uncomment the following line in the /etc/libvirt/qemu.conf file:
   

   cgroup_controllers = [ "cpu", "devices", "memory", "blkio", "cpuacct" ]

3. Restart libvirt:

   systemctl restart libvirtd.service