trentdocs_website/site/stupid_kvm_tricks/index.html

356 lines
12 KiB
HTML
Raw Normal View History

2018-02-10 23:31:16 -08:00
<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="shortcut icon" href="../img/favicon.ico">
<title>Stupid KVM Tricks - Trent Docs</title>
<link href='https://fonts.googleapis.com/css?family=Lato:400,700|Roboto+Slab:400,700|Inconsolata:400,700' rel='stylesheet' type='text/css'>
<link rel="stylesheet" href="../css/theme.css" type="text/css" />
<link rel="stylesheet" href="../css/theme_extra.css" type="text/css" />
<link rel="stylesheet" href="../css/highlight.css">
<script>
// Current page data
var mkdocs_page_name = "Stupid KVM Tricks";
var mkdocs_page_input_path = "stupid_kvm_tricks.md";
var mkdocs_page_url = "/stupid_kvm_tricks/";
</script>
<script src="../js/jquery-2.1.1.min.js"></script>
<script src="../js/modernizr-2.8.3.min.js"></script>
<script type="text/javascript" src="../js/highlight.pack.js"></script>
</head>
<body class="wy-body-for-nav" role="document">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side stickynav">
<div class="wy-side-nav-search">
<a href=".." class="icon icon-home"> Trent Docs</a>
<div role="search">
<form id ="rtd-search-form" class="wy-form" action="../search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
</form>
</div>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<ul class="current">
<li class="toctree-l1">
<a class="" href="..">Home</a>
</li>
<li class="toctree-l1">
<a class="" href="../apt_pinning_artful_aardvark_packages_in_xenial_xerus/">Apt Pinning Artful Aardvark Packages in Xenial Xerus</a>
</li>
<li class="toctree-l1">
<a class="" href="../lxd_container_home_server_networking_for_dummies/">LXD Container Home Server Networking For Dummies</a>
</li>
<li class="toctree-l1">
<a class="" href="../lxd_container_foo/">LXD Container Foo</a>
</li>
<li class="toctree-l1">
<a class="" href="../how_to_reassign_a_static_ip_address_with_dnsmasq/">How To Reassign A Static Ip Address with dnsmasq</a>
</li>
<li class="toctree-l1">
<a class="" href="../serve_and_share_apps_from_your_phone_with_fdroid/">Serve And Share Apps From Your Phone With Fdroid</a>
</li>
<li class="toctree-l1">
<a class="" href="../nspawn/">Nspawn</a>
</li>
<li class="toctree-l1">
<a class="" href="../gentoo_lxd_container/">Gentoo LXD Container</a>
</li>
<li class="toctree-l1">
<a class="" href="../mastodon_on_arch/">Mastodon on Arch</a>
</li>
<li class="toctree-l1">
<a class="" href="../debian_nspawn_container_on_arch_for_testing_apache_configurations/">Debian Nspawn Container On Arch For Testing Apache Configurations</a>
</li>
<li class="toctree-l1">
<a class="" href="../dynamic_cacheing_nginx_reverse_proxy_for_pacman/">Dynamic Cacheing Nginx Reverse Proxy For Pacman</a>
</li>
<li class="toctree-l1">
<a class="" href="../freebsd_jails_on_freenas/">FreeBSD Jails on FreeNAS</a>
</li>
<li class="toctree-l1">
<a class="" href="../arch_redis_nspawn/">Quick Dirty Redis Nspawn Container on Arch Linux</a>
</li>
<li class="toctree-l1">
<a class="" href="../arch_postgresql_nspawn/">Quick Dirty Postgresql Nspawn Container on Arch Linux</a>
</li>
<li class="toctree-l1">
<a class="" href="../misc_tips_troubleshooting/">Misc Tips, Trouble Shooting</a>
</li>
<li class="toctree-l1">
<a class="" href="../self_signed_certs/">Self Signed Certs</a>
</li>
<li class="toctree-l1">
<a class="" href="../selfoss_on_centos7/">Selfoss on Centos7</a>
</li>
<li class="toctree-l1">
<a class="" href="../stupid_package_manager_tricks/">Stupid Package Manager Tricks</a>
</li>
<li class="toctree-l1 current">
<a class="current" href="./">Stupid KVM Tricks</a>
<ul class="subnav">
<li class="toctree-l2"><a href="#stupid-kvm-tricks">Stupid KVM Tricks</a></li>
<ul>
<li><a class="toctree-l3" href="#virt-install-ubuntu1604">virt-install ubuntu16.04</a></li>
<li><a class="toctree-l3" href="#change-the-network-interface">Change the Network Interface</a></li>
<li><a class="toctree-l3" href="#clone-the-vm">Clone the VM</a></li>
<li><a class="toctree-l3" href="#clone-the-vm-to-another-machine">Clone the VM to another Machine</a></li>
<li><a class="toctree-l3" href="#what-is-the-os-type-and-os-variant-type-names">What is the os-type and os-variant type names?</a></li>
<li><a class="toctree-l3" href="#misc">misc</a></li>
<li><a class="toctree-l3" href="#virsh-help">virsh help</a></li>
</ul>
</ul>
</li>
</ul>
</div>
&nbsp;
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" role="navigation" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="..">Trent Docs</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="..">Docs</a> &raquo;</li>
<li>Stupid KVM Tricks</li>
<li class="wy-breadcrumbs-aside">
</li>
</ul>
<hr/>
</div>
<div role="main">
<div class="section">
<h1 id="stupid-kvm-tricks">Stupid KVM Tricks</h1>
<h2 id="virt-install-ubuntu1604">virt-install ubuntu16.04</h2>
<p>Create the disk image</p>
<p><code>qemu-img create -f qcow2 /var/lib/libvirt/images/xenial.qcow2 20G</code></p>
<p>Command to run the install</p>
<pre><code class="bash">virt-install \
--name xenial \
--ram 4096 \
--disk path=/var/lib/libvirt/images/xenial.qcow2,size=20 \
--vcpus 4 \
--os-type linux \
--os-variant ubuntu16.04 \
--network bridge=br0 \
--graphics none \
--console pty,target_type=serial \
--location ./ubuntu-16.04.3-server-amd64.iso \
--extra-args 'console=ttyS0,115200n8 serial'
</code></pre>
<h2 id="change-the-network-interface">Change the Network Interface</h2>
<p>br0 gets addresses from the network router, but what if you want
your vm to have be on the virbr0 192.168.122.0/24 subnet?</p>
<p><code>virsh edit xenial</code></p>
<p>And then 'J' all the way down to the bottom, change the interface name from br0 to
virbr0, </p>
<p><code>virsh start xenial</code></p>
<p>and then look for the machine with nmap</p>
<p><code>nmap -sn 192.168.122.0/24</code></p>
<h2 id="clone-the-vm">Clone the VM</h2>
<p>In this case we don't have to pre-allocate the disk image because virt-clone will do that
for us.</p>
<pre><code class="bash">virt-clone --original xenial --name xenial-clone \
--file /var/lib/libvirt/images/xenial-clone.qcow2
</code></pre>
<h2 id="clone-the-vm-to-another-machine">Clone the VM to another Machine</h2>
<p>First dump the xml that defines the virtual machine.</p>
<pre><code class="bash">virsh dumpxml xenial &gt; xenial.xml
</code></pre>
<p>Then copy both <code>xenial.xml</code> and <code>xenial.qcow2</code> to the new host machine. On the new kvm
host you'll want to at least make sure your vm has the correct CPU architecture.
The command to get a list of supported kvm cpu architectures is:</p>
<pre><code class="bash">virsh cpu-models &lt;arch&gt;
# i.e.
virsh cpu-models x86_64
</code></pre>
<p>After you edit <code>xenial.xml</code> and update the correct cpu architecture, mv <code>xenial.qcow2</code>
to <code>/var/lib/libvirt/images/</code>, clone it. <code>virt-clone</code> will handle generating new
mac addresses for the network interfaces.</p>
<pre><code class="xml"> &lt;cpu mode='custom' match='exact'&gt;
&lt;model fallback='allow'&gt;Haswell-noTSX&lt;/model&gt;
&lt;/cpu&gt;
# i.e. change to above to
&lt;cpu mode='custom' match='exact'&gt;
&lt;model fallback='allow'&gt;SandyBridge&lt;/model&gt;
&lt;/cpu&gt;
</code></pre>
<pre><code class="bash">virt-clone --original-xml xenial.xml --name xenial-clone \
--file /var/lib/libvirt/images/xenial-clone.qcow2
</code></pre>
<h2 id="what-is-the-os-type-and-os-variant-type-names">What is the os-type and os-variant type names?</h2>
<p><code>osinfo-query os</code></p>
<h2 id="misc">misc</h2>
<ul>
<li>Start the vm <code>virsh start xenial</code> </li>
<li>List all the vms <code>virsh list --all</code> </li>
<li>Stop the vm <code>virsh destroy xenial</code> </li>
<li>Delete the vm <code>virsh undefine xenial</code> </li>
</ul>
<h2 id="virsh-help">virsh help</h2>
<p>The <code>virsh help</code> command returns a long chart of help information. But each section has
a keyword.</p>
<p>Take for instance the command <code>virsh help monitor</code>. From this we
see the <code>domiflist</code> subcommand (among others). Unfortunately <code>domifaddr</code> doesn't seem to
work on the Ubuntu:16.04 host, but there are other ways to find the ip address of
a virtual machine.</p>
<p>So now if you want to see what host interface the vm <code>xenial</code> is attached to,
type. </p>
<pre><code class="bash">virsh domiflist xenial
</code></pre>
<p>which returns:</p>
<pre><code class="bash">Interface Type Source Model MAC
-------------------------------------------------------
vnet1 bridge virbr0 virtio 52:54:00:58:bf:75
</code></pre>
<p>So now we can find the address of virbr0 on the host machine.</p>
<pre><code class="bash">ifconfig virbr0
</code></pre>
<p>which returns:</p>
<pre><code class="bash">virbr0 Link encap:Ethernet HWaddr 52:54:00:38:87:38
inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1351 errors:0 dropped:0 overruns:0 frame:0
TX packets:3037 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:232346 (232.3 KB) TX bytes:502916 (502.9 KB)
</code></pre>
<p>and thus we know what subnet to scan with nmap to find the ip address of the vm</p>
<pre><code class="bash">nmap -sn 192.168.122.0/24
</code></pre>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="../stupid_package_manager_tricks/" class="btn btn-neutral" title="Stupid Package Manager Tricks"><span class="icon icon-circle-arrow-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<!-- Copyright etc -->
</div>
Built with <a href="http://www.mkdocs.org">MkDocs</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<div class="rst-versions" role="note" style="cursor: pointer">
<span class="rst-current-version" data-toggle="rst-current-version">
<span><a href="../stupid_package_manager_tricks/" style="color: #fcfcfc;">&laquo; Previous</a></span>
</span>
</div>
<script>var base_url = '..';</script>
<script src="../js/theme.js"></script>
<script src="../search/require.js"></script>
<script src="../search/search.js"></script>
</body>
</html>