Virtualization Notes


If your processor supports vmx (cat /proc/cpuinfo | grep vmx), you can install QEMU/KVM for faster VMs.

yum install kvm kmod-kvm qemu libvirt  
service libvirtd start

You can now connect to the instance with virt-manager.


If virt-manager reports that you don’t have KVM support, check your BIOS and enable virtualization (VT for Intel processors) and power cycle the server. Then check if the kernel module is inserted properly:

lsmod | grep kvm  
# If not  
modprobe kvm  
modprobe kvm-intel

If the last commands don’t work, make sure your kernel isn’t Xen!. I made this mistake and switching to a non-Xen kernel ensured that the KVM kernel module was inserted properly.

could not query memory balloon allocation

You can only give a VM 4GiB of memory under QEMU

MP-BIOS bug: 8254 timer not connected to IO_APIC

Add a noapic to your kernel boot params.