External/libvirt
1
0
Fork 0
mirror of https://gitlab.com/libvirt/libvirt.git synced 2024-12-23 14:15:28 +00:00
Code Issues Packages Projects Releases Wiki Activity
184fc07fda
libvirt/docs/drvlxc.html.in

140 lines
3.9 KiB
HTML
Raw Normal View History

Split website out into one file per page. APply new layout and styling
2008-04-23 17:08:31 +00:00
<html>
<body>
<h1>LXC container driver</h1>
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
<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
website: Point main page links to libvirt driver pages The "libvirt supports:" section on the main page of libvirt.org contains a list of hypervisors with links that point to the sites of the underlying virt technologies. The entry for KVM points to http://www.linux-kvm.org/, for example. People coming to libvirt.org for the first time are likely to know about those sites, and they're probably interested in how libvirt manages those technologies. This patch points those links to the libvirt driver pages instead. It also consolidates KVM and QEMU as there is only one libvirt driver page for them. Finally, it adds a line about networking support. v2: incorporate Eric's feedback adding project links to driver pages. website: Add project links to KVM/QEMU driver page website: Add project links to Xen driver page website: Add project links to LXC driver page website: Add project links to OpenVZ driver page website: Add project links to UML driver page website: Add project links to Virtualbox driver page website: Add project links to ESX driver page website: Add project links to VMware driver page
2011-07-15 18:33:17 +00:00
light-weight "application container" which does not have its own root image.
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
</p>
website: Point main page links to libvirt driver pages The "libvirt supports:" section on the main page of libvirt.org contains a list of hypervisors with links that point to the sites of the underlying virt technologies. The entry for KVM points to http://www.linux-kvm.org/, for example. People coming to libvirt.org for the first time are likely to know about those sites, and they're probably interested in how libvirt manages those technologies. This patch points those links to the libvirt driver pages instead. It also consolidates KVM and QEMU as there is only one libvirt driver page for them. Finally, it adds a line about networking support. v2: incorporate Eric's feedback adding project links to driver pages. website: Add project links to KVM/QEMU driver page website: Add project links to Xen driver page website: Add project links to LXC driver page website: Add project links to OpenVZ driver page website: Add project links to UML driver page website: Add project links to Virtualbox driver page website: Add project links to ESX driver page website: Add project links to VMware driver page
2011-07-15 18:33:17 +00:00
<h2><a name="project">Project Links</a></h2>
<ul>
<li>
The <a href="http://lxc.sourceforge.net/">LXC</a> Linux
container system
</li>
</ul>
Make LXC container startup/shutdown/I/O more robust The current LXC I/O controller looks for HUP to detect when a guest has quit. This isn't reliable as during initial bootup it is possible that 'init' will close the console and let mingetty re-open it. The shutdown of containers was also flakey because it only killed the libvirt I/O controller and expected container processes to gracefully follow. Change the I/O controller such that when it see HUP or an I/O error, it uses kill($PID, 0) to see if the process has really quit. Change the container shutdown sequence to use the virCgroupKillPainfully function to ensure every really goes away This change makes the use of the 'cpu', 'devices' and 'memory' cgroups controllers compulsory with LXC * docs/drvlxc.html.in: Document that certain cgroups controllers are now mandatory * src/lxc/lxc_controller.c: Check if PID is still alive before quitting on I/O error/HUP * src/lxc/lxc_driver.c: Use virCgroupKillPainfully
2011-02-22 17:35:06 +00:00
<h2>Cgroups Requirements</h2>
<p>
The libvirt LXC driver requires that certain cgroups controllers are
mounted on the host OS. The minimum required controllers are 'cpuacct',
'memory' and 'devices', while recommended extra controllers are
'cpu', 'freezer' and 'blkio'. The /etc/cgconfig.conf &amp; cgconfig
init service used to mount cgroups at host boot time. To manually
mount them use:
</p>
<pre>
# mount -t cgroup cgroup /dev/cgroup -o cpuacct,memory,devices,cpu,freezer,blkio
</pre>
<p>
NB, the blkio controller in some kernels will not allow creation of nested
sub-directories which will prevent correct operation of the libvirt LXC
driver. On such kernels, it may be neccessary to unmount the blkio controller.
</p>
Allow passing of command line args to LXC container When booting a virtual machine with a kernel/initrd it is possible to pass command line arguments using the <cmdline>...args...</cmdline> element in the guest XML. These appear to the kernel / init process in /proc/cmdline. When booting a container we do not have a custom /proc/cmdline, but we can easily set an environment variable for it. Ideally we could pass individual arguments to the init process as a regular set of 'char *argv[]' parameters, but that would involve libvirt parsing the <cmdline> XML text. This can easily be added later, even if we add the env variable now * docs/drvlxc.html.in: Document env variables passed to LXC * src/conf/domain_conf.c: Add <cmdline> to be parsed for guests of type='exe' * src/lxc/lxc_container.c: Set LIBVIRT_LXC_CMDLINE env var
2011-10-03 17:37:47 +00:00
<h2>Environment setup for the container init</h2>
<p>
When the container "init" process is started, it will be given several useful
environment variables.
</p>
<dl>
<dt>LIBVIRT_LXC_NAME</dt>
<dd>The name assigned to the container by libvirt</dd>
<dt>LIBVIRT_LXC_UUID</dt>
<dd>The UUID assigned to the container by libvirt</dd>
<dt>LIBVIRT_LXC_CMDLINE</dt>
<dd>The unparsed command line arguments specified in the container configuration</dd>
</dl>
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
<h3>Example config version 1</h3>
<p></p>
<pre>
&lt;domain type='lxc'&gt;
Whitespace cleanup for pre-tags on the website
2009-11-13 23:09:20 +00:00
&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;
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
&lt;/domain&gt;
</pre>
docs: fix lxc examples * docs/drvlxc.html.in: Use correct VM name, and mention that libvirt_lxc might be in an alternate location.
2010-06-15 22:46:21 +00:00
<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>
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
<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;
Whitespace cleanup for pre-tags on the website
2009-11-13 23:09:20 +00:00
&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;
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
&lt;/domain&gt;
</pre>
<p>
In both cases, you can define and start a container using:</p>
<pre>
Small doc fixes * src/libvirt.c: fix the doc of virNodeGetFreeMemory to say bytes * docs/drvlxc.html.in docs/drvlxc.html: fix command used in examples daniel
2009-04-17 15:34:53 +00:00
virsh --connect lxc:/// define v1.xml
docs: fix lxc examples * docs/drvlxc.html.in: Use correct VM name, and mention that libvirt_lxc might be in an alternate location.
2010-06-15 22:46:21 +00:00
virsh --connect lxc:/// start vm1
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
</pre>
and then get a console using:
<pre>
docs: fix lxc examples * docs/drvlxc.html.in: Use correct VM name, and mention that libvirt_lxc might be in an alternate location.
2010-06-15 22:46:21 +00:00
virsh --connect lxc:/// console vm1
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
</pre>
<p>Now doing 'ps -ef' will only show processes in the container, for
docs: fix lxc examples * docs/drvlxc.html.in: Use correct VM name, and mention that libvirt_lxc might be in an alternate location.
2010-06-15 22:46:21 +00:00
instance. You can undefine it using
* drvlxc.html.in drvlxc.html: some examples from Serge Hallyn daniel
2009-04-15 20:00:29 +00:00
</p>
docs: fix lxc examples * docs/drvlxc.html.in: Use correct VM name, and mention that libvirt_lxc might be in an alternate location.
2010-06-15 22:46:21 +00:00
<pre>
virsh --connect lxc:/// undefine vm1
</pre>
Split website out into one file per page. APply new layout and styling
2008-04-23 17:08:31 +00:00
</body>
</html>
Reference in New Issue Copy Permalink