drvlxc.html.in

<html>
  <body>
    <h1>LXC container driver</h1>
<p>
The libvirt LXC driver manages "Linux Containers".  Containers are sets of processes
with private namespaces which can (but don't always) look like separate machines, but
do not have their own OS.  Here are two example configurations.  The first is a very
light-weight "application container" which does not have it's own root image.  You would
start it using
</p>

<h3>Example config version 1</h3>
<p></p>
<pre>
&lt;domain type='lxc'&gt;
  &lt;name&gt;vm1&lt;/name&gt;
  &lt;memory&gt;500000&lt;/memory&gt;
  &lt;os&gt;
    &lt;type&gt;exe&lt;/type&gt;
    &lt;init&gt;/bin/sh&lt;/init&gt;
  &lt;/os&gt;
  &lt;vcpu&gt;1&lt;/vcpu&gt;
  &lt;clock offset='utc'/&gt;
  &lt;on_poweroff&gt;destroy&lt;/on_poweroff&gt;
  &lt;on_reboot&gt;restart&lt;/on_reboot&gt;
  &lt;on_crash&gt;destroy&lt;/on_crash&gt;
  &lt;devices&gt;
    &lt;emulator&gt;/usr/libexec/libvirt_lxc&lt;/emulator&gt;
    &lt;interface type='network'&gt;
      &lt;source network='default'/&gt;
    &lt;/interface&gt;
    &lt;console type='pty' /&gt;
  &lt;/devices&gt;
&lt;/domain&gt;
</pre>

<p>
In the &lt;emulator&gt; element, be sure you specify the correct path
to libvirt_lxc, if it does not live in /usr/libexec on your system.
</p>

<p>
The next example assumes there is a private root filesystem
(perhaps hand-crafted using busybox, or installed from media,
debootstrap, whatever) under /opt/vm-1-root:
</p>
<p></p>
<pre>
&lt;domain type='lxc'&gt;
  &lt;name&gt;vm1&lt;/name&gt;
  &lt;memory&gt;32768&lt;/memory&gt;
  &lt;os&gt;
    &lt;type&gt;exe&lt;/type&gt;
    &lt;init&gt;/init&lt;/init&gt;
  &lt;/os&gt;
  &lt;vcpu&gt;1&lt;/vcpu&gt;
  &lt;clock offset='utc'/&gt;
  &lt;on_poweroff&gt;destroy&lt;/on_poweroff&gt;
  &lt;on_reboot&gt;restart&lt;/on_reboot&gt;
  &lt;on_crash&gt;destroy&lt;/on_crash&gt;
  &lt;devices&gt;
    &lt;emulator&gt;/usr/libexec/libvirt_lxc&lt;/emulator&gt;
    &lt;filesystem type='mount'&gt;
      &lt;source dir='/opt/vm-1-root'/&gt;
      &lt;target dir='/'/&gt;
    &lt;/filesystem&gt;
    &lt;interface type='network'&gt;
      &lt;source network='default'/&gt;
    &lt;/interface&gt;
    &lt;console type='pty' /&gt;
  &lt;/devices&gt;
&lt;/domain&gt;
</pre>

<p>
In both cases, you can define and start a container using:</p>
<pre>
virsh --connect lxc:/// define v1.xml
virsh --connect lxc:/// start vm1
</pre>
and then get a console  using:
<pre>
virsh --connect lxc:/// console vm1
</pre>
<p>Now doing 'ps -ef' will only show processes in the container, for
instance.  You can undefine it using
</p>
<pre>
virsh --connect lxc:/// undefine vm1
</pre>
  </body>
</html>