man/systemd-detect-virt.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="systemd-detect-virt"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>systemd-detect-virt</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>systemd-detect-virt</refentrytitle>
  16     <manvolnum>1</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>systemd-detect-virt</refname>
  21     <refpurpose>Detect execution in a virtualized environment</refpurpose>
  22   </refnamediv>
  23
  24   <refsynopsisdiv>
  25     <cmdsynopsis>
  26       <command>systemd-detect-virt</command>
  27       <arg choice="opt" rep="repeat">OPTIONS</arg>
  28     </cmdsynopsis>
  29   </refsynopsisdiv>
  30
  31   <refsect1>
  32     <title>Description</title>
  33
  34     <para><command>systemd-detect-virt</command> detects execution in
  35     a virtualized environment. It identifies the virtualization
  36     technology and can distinguish full machine virtualization from
  37     container virtualization. <filename>systemd-detect-virt</filename>
  38     exits with a return value of 0 (success) if a virtualization
  39     technology is detected, and non-zero (error) otherwise. By default,
  40     any type of virtualization is detected, and the options
  41     <option>--container</option> and <option>--vm</option> can be used
  42     to limit what types of virtualization are detected.</para>
  43
  44     <para>When executed without <option>--quiet</option> will print a
  45     short identifier for the detected virtualization technology. The
  46     following technologies are currently identified:</para>
  47
  48     <table>
  49       <title>Known virtualization technologies (both
  50       VM, i.e. full hardware virtualization,
  51       and container, i.e. shared kernel virtualization)</title>
  52       <tgroup cols='3' align='left' colsep='1' rowsep='1'>
  53         <colspec colname="type" />
  54         <colspec colname="id" />
  55         <colspec colname="product" />
  56         <thead>
  57           <row>
  58             <entry>Type</entry>
  59             <entry>ID</entry>
  60             <entry>Product</entry>
  61           </row>
  62         </thead>
  63         <tbody>
  64           <row>
  65             <entry valign="top" morerows="12">VM</entry>
  66             <entry><varname>qemu</varname></entry>
  67             <entry>QEMU software virtualization, without KVM</entry>
  68           </row>
  69
  70           <row>
  71             <entry><varname>kvm</varname></entry>
  72             <entry>Linux KVM kernel virtual machine, with whatever software, except Oracle Virtualbox</entry>
  73           </row>
  74
  75           <row>
  76             <entry><varname>zvm</varname></entry>
  77             <entry>s390 z/VM</entry>
  78           </row>
  79
  80           <row>
  81             <entry><varname>vmware</varname></entry>
  82             <entry>VMware Workstation or Server, and related products</entry>
  83           </row>
  84
  85           <row>
  86             <entry><varname>microsoft</varname></entry>
  87             <entry>Hyper-V, also known as Viridian or Windows Server Virtualization</entry>
  88           </row>
  89
  90           <row>
  91             <entry><varname>oracle</varname></entry>
  92             <entry>Oracle VM VirtualBox (historically marketed by innotek and Sun Microsystems), for legacy and KVM hypervisor</entry>
  93           </row>
  94
  95           <row>
  96             <entry><varname>xen</varname></entry>
  97             <entry>Xen hypervisor (only domU, not dom0)</entry>
  98           </row>
  99
 100           <row>
 101             <entry><varname>bochs</varname></entry>
 102             <entry>Bochs Emulator</entry>
 103           </row>
 104
 105           <row>
 106             <entry><varname>uml</varname></entry>
 107             <entry>User-mode Linux</entry>
 108           </row>
 109
 110           <row>
 111             <entry><varname>parallels</varname></entry>
 112             <entry>Parallels Desktop, Parallels Server</entry>
 113           </row>
 114
 115           <row>
 116             <entry><varname>bhyve</varname></entry>
 117             <entry>bhyve, FreeBSD hypervisor</entry>
 118           </row>
 119
 120           <row>
 121             <entry><varname>qnx</varname></entry>
 122             <entry>QNX hypervisor</entry>
 123           </row>
 124
 125           <row>
 126             <entry><varname>acrn</varname></entry>
 127             <entry><ulink url="https://projectacrn.org">ACRN hypervisor</ulink></entry>
 128           </row>
 129
 130           <row>
 131             <entry valign="top" morerows="7">Container</entry>
 132             <entry><varname>openvz</varname></entry>
 133             <entry>OpenVZ/Virtuozzo</entry>
 134           </row>
 135
 136           <row>
 137             <entry><varname>lxc</varname></entry>
 138             <entry>Linux container implementation by LXC</entry>
 139           </row>
 140
 141           <row>
 142             <entry><varname>lxc-libvirt</varname></entry>
 143             <entry>Linux container implementation by libvirt</entry>
 144           </row>
 145
 146           <row>
 147             <entry><varname>systemd-nspawn</varname></entry>
 148             <entry>systemd's minimal container implementation, see <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry></entry>
 149           </row>
 150
 151           <row>
 152             <entry><varname>docker</varname></entry>
 153             <entry>Docker container manager</entry>
 154           </row>
 155
 156           <row>
 157             <entry><varname>podman</varname></entry>
 158             <entry><ulink url="https://podman.io">Podman</ulink> container manager</entry>
 159           </row>
 160
 161           <row>
 162             <entry><varname>rkt</varname></entry>
 163             <entry>rkt app container runtime</entry>
 164           </row>
 165
 166           <row>
 167             <entry><varname>wsl</varname></entry>
 168             <entry><ulink url="https://docs.microsoft.com/en-us/windows/wsl/about">Windows Subsystem for Linux</ulink></entry>
 169           </row>
 170         </tbody>
 171       </tgroup>
 172     </table>
 173
 174     <para>If multiple virtualization solutions are used, only the
 175     "innermost" is detected and identified. That means if both
 176     machine and container virtualization are used in
 177     conjunction, only the latter will be identified (unless
 178     <option>--vm</option> is passed).</para>
 179     <para> Windows Subsystem for Linux is not a Linux container,
 180     but an environment for running Linux userspace applications on
 181     top of the Windows kernel using a Linux-compatible interface.
 182     WSL is categorized as a container for practical purposes.
 183     Multiple WSL environments share the same kernel and services
 184     should generally behave like when being run in a container.</para>
 185   </refsect1>
 186
 187   <refsect1>
 188     <title>Options</title>
 189
 190     <para>The following options are understood:</para>
 191
 192     <variablelist>
 193       <varlistentry>
 194         <term><option>-c</option></term>
 195         <term><option>--container</option></term>
 196
 197         <listitem><para>Only detects container virtualization (i.e.
 198         shared kernel virtualization).</para></listitem>
 199       </varlistentry>
 200
 201       <varlistentry>
 202         <term><option>-v</option></term>
 203         <term><option>--vm</option></term>
 204
 205         <listitem><para>Only detects hardware virtualization.</para></listitem>
 206       </varlistentry>
 207
 208       <varlistentry>
 209         <term><option>-r</option></term>
 210         <term><option>--chroot</option></term>
 211
 212         <listitem><para>Detect whether invoked in a
 213         <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 214         environment. In this mode, no output is written, but the return
 215         value indicates whether the process was invoked in a
 216         <function>chroot()</function>
 217         environment or not.</para></listitem>
 218       </varlistentry>
 219
 220       <varlistentry>
 221         <term><option>--private-users</option></term>
 222
 223         <listitem><para>Detect whether invoked in a user namespace.  In this mode, no
 224         output is written, but the return value indicates whether the process was invoked
 225         inside of a user namespace or not. See
 226         <citerefentry project='man-pages'><refentrytitle>user_namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 227         for more information.</para></listitem>
 228       </varlistentry>
 229
 230       <varlistentry>
 231         <term><option>-q</option></term>
 232         <term><option>--quiet</option></term>
 233
 234         <listitem><para>Suppress output of the virtualization
 235         technology identifier.</para></listitem>
 236       </varlistentry>
 237
 238       <varlistentry>
 239         <term><option>--list</option></term>
 240
 241         <listitem><para>Output all currently known and detectable container and VM environments.</para></listitem>
 242       </varlistentry>
 243
 244       <xi:include href="standard-options.xml" xpointer="help" />
 245       <xi:include href="standard-options.xml" xpointer="version" />
 246     </variablelist>
 247
 248   </refsect1>
 249
 250   <refsect1>
 251     <title>Exit status</title>
 252
 253     <para>If a virtualization technology is detected, 0 is returned, a
 254     non-zero code otherwise.</para>
 255   </refsect1>
 256
 257   <refsect1>
 258     <title>See Also</title>
 259     <para>
 260       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 261       <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 262       <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 263       <citerefentry project='man-pages'><refentrytitle>namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 264     </para>
 265   </refsect1>
 266
 267 </refentry>