mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2024-12-27 16:15:23 +00:00
47 lines
2.4 KiB
XML
47 lines
2.4 KiB
XML
<?xml version="1.0"?>
|
|
<html>
|
|
<body>
|
|
<h1>Architecture</h1>
|
|
<p>Libvirt is a C toolkit to interact with the virtualization capabilities of
|
|
recent versions of Linux (and other OSes), but libvirt won't try to provide
|
|
all possible interfaces for interacting with the virtualization features.</p>
|
|
<p>To avoid ambiguity about the terms used here here are the definitions for
|
|
some of the specific concepts used in libvirt documentation:</p>
|
|
<ul>
|
|
<li>a <strong>node</strong> is a single physical machine</li>
|
|
<li>an <strong>hypervisor</strong> is a layer of software allowing to
|
|
virtualize a node in a set of virtual machines with possibly different
|
|
configurations than the node itself</li>
|
|
<li>a <strong>domain</strong> is an instance of an operating system running
|
|
on a virtualized machine provided by the hypervisor</li>
|
|
</ul>
|
|
<p class="image">
|
|
<img alt="Hypervisor and domains running on a node" src="node.gif"/>
|
|
</p>
|
|
<p>Now we can define the goal of libvirt: to provide the lowest possible
|
|
generic and stable layer to manage domains on a node.</p>
|
|
<p>This implies the following:</p>
|
|
<ul>
|
|
<li>the API should not be targeted to a single virtualization environment
|
|
though Xen is the current default, which also means that some very
|
|
specific capabilities which are not generic enough may not be provided as
|
|
libvirt APIs</li>
|
|
<li>the API should allow to do efficiently and cleanly all the operations
|
|
needed to manage domains on a node</li>
|
|
<li>the API will not try to provide high level multi-nodes management
|
|
features like load balancing, though they could be implemented on top of
|
|
libvirt</li>
|
|
<li>stability of the API is a big concern, libvirt should isolate
|
|
applications from the frequent changes expected at the lower level of the
|
|
virtualization framework</li>
|
|
</ul>
|
|
<p>So libvirt should be a building block for higher level management tools
|
|
and for applications focusing on virtualization of a single node (the only
|
|
exception being domain migration between node capabilities which may need to
|
|
be added at the libvirt level). Where possible libvirt should be extendable
|
|
to be able to provide the same API for remote nodes, however this is not the
|
|
case at the moment, the code currently handle only local node accesses
|
|
(extension for remote access support is being worked on, see <a href="bugs.html">the mailing list</a> discussions about it).</p>
|
|
</body>
|
|
</html>
|