OpenStack Compute supports many hypervisors, an array of which must provide a bit of difficulty in selecting a hypervisor unless you are already familiar with one. Most installations only use a single hypervisor, however it is possible to use the ComputeFilter and ImagePropertiesFilter to allow scheduling to different hypervisors within the same installation. The following links provide additional information for choosing a hypervisor. Refer to http://wiki.openstack.org/HypervisorSupportMatrix for a detailed list of features and support across the hypervisors.
Here is a list of the supported hypervisors with links to a relevant web site for configuration and use:
KVM - Kernel-based Virtual Machine. The virtual disk formats that it supports it inherits from QEMU since it uses a modified QEMU program to launch the virtual machine. The supported formats include raw images, the qcow2, and VMware formats.
LXC - Linux Containers (through libvirt), use to run Linux-based virtual machines.
QEMU - Quick EMUlator, generally only used for development purposes.
UML - User Mode Linux, generally only used for development purposes.
VMWare vSphere 4.1 update 1 and newer, runs VMWare-based Linux and Windows images through a connection with a vCenter server or directly with an ESXi host.
Xen - XenServer, Xen Cloud Platform (XCP), use to run Linux or Windows virtual machines. You must install the nova-compute service in a para-virtualized VM.
PowerVM - Server virtualization with IBM PowerVM, use to run AIX, IBM i and Linux environments on IBM POWER technology.
Hyper-V - Server virtualization with Microsoft's Hyper-V, use to run Windows, Linux, and FreeBSD virtual machines. Runs nova-compute natively on the Windows virtualization platform.
Bare Metal - Not a hypervisor in the traditional sense, this driver provisions physical hardware via pluggable sub-drivers (eg. PXE for image deployment, and IPMI for power management).
