3.2. libvirt and libvirt Tools

The libvirt package provides a hypervisor-independent virtualization API that can interact with the virtualization capabilities of a range of operating systems. It includes:
  • A virtualization layer to securely manage virtual machines on a host.
  • An interface for managing local and networked hosts.
  • The APIs required to provision, create, modify, monitor, control, migrate, and stop virtual machines. Although multiple hosts may be accessed with libvirt simultaneously, the APIs are limited to single node operations.

    Note

    Only operations supported by the hypervisor can be performed using libvirt.
libvirt focuses on managing single hosts and provides APIs to enumerate, monitor and use the resources available on the managed node, including CPUs, memory, storage, networking and Non-Uniform Memory Access (NUMA) partitions. The management tools do not need to be on the same physical machine as the machines on which the hosts are running. In such a scenario, the machine on which management tools run communicates with the machines on which the hosts are running using secure protocols.
Red Hat Enterprise Linux 6 supports libvirt and includes libvirt-based tools as its default method for virtualization management (as in Red Hat Virtualization Management).
The libvirt package is available as free software under the GNU Lesser General Public License. The libvirt project aims to provide a long term stable C API to virtualization management tools, running on top of varying hypervisor technologies. The libvirt package supports Xen on Red Hat Enterprise Linux 5, and it supports KVM on both Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6.
Notably, libvirt also provides the two central tools for controlling virtualization on Red Hat Enterprise Linux 6: virsh and virt-manager