QEMU
From the perspective of the Compute service, the QEMU hypervisor is very similar to the KVM
hypervisor. Both are controlled through libvirt, both support the same feature set, and all
virtual machine images that are compatible with KVM are also compatible with QEMU. The main
difference is that QEMU does not support native virtualization. Consequently, QEMU has worse
performance than KVM and is a poor choice for a production deployment.
The typical uses cases for QEMU are
Running on older hardware that lacks
virtualization support.
Running the Compute service inside of a virtual
machine for development or testing purposes, where
the hypervisor does not support native
virtualization for guests.
To enable QEMU, add these settings to
nova.conf:compute_driver = libvirt.LibvirtDriver
[libvirt]
virt_type = qemu
For some operations you may also have to install the guestmount utility:
On Ubuntu:
# apt-get install guestmount
On Red Hat Enterprise Linux, Fedora, or CentOS:
# yum install libguestfs-tools
On openSUSE:
# zypper install guestfs-tools
The QEMU hypervisor supports the following virtual machine image formats:
Raw
QEMU Copy-on-write (qcow2)
VMware virtual machine disk format (vmdk)