Virtualization Notes Revision as of Saturday, 9 April 2016 at 16:03 UTC
Installation
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.
Errors
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.