OpenStack nested virtual machines

Running a virtual machine within a virtual machine (aka nested virtual machines) is supported by OpenStack by adding a stanza such as

    <cpu mode='custom' match='exact'>
      <feature policy='require' name='vmx'/>

in the libvirt.xml.template file. The nested feature must be enabled on the OpenStack node for intel processors by adding the nested=1 argument when loading the kvm_intel module so that:

# cat /sys/module/kvm_intel/parameters/nested

This feature can be used to exercise an automated Openstack deployement on Debian GNU/Linux wheezy with razor within OpenStack itself.
Continue reading “OpenStack nested virtual machines”