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="8">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
 171           <row>
 172             <entry><varname>proot</varname></entry>
 173             <entry><ulink url="https://proot-me.github.io/">proot</ulink> userspace chroot/bind mount emulation</entry>
 174           </row>
 175
 176           <row>
 177             <entry><varname>pouch</varname></entry>
 178             <entry><ulink url="https://github.com/alibaba/pouch">Pouch</ulink> Container Engine</entry>
 179           </row>
 180         </tbody>
 181       </tgroup>
 182     </table>
 183
 184     <para>If multiple virtualization solutions are used, only the
 185     "innermost" is detected and identified. That means if both
 186     machine and container virtualization are used in
 187     conjunction, only the latter will be identified (unless
 188     <option>--vm</option> is passed).</para>
 189     <para> Windows Subsystem for Linux is not a Linux container,
 190     but an environment for running Linux userspace applications on
 191     top of the Windows kernel using a Linux-compatible interface.
 192     WSL is categorized as a container for practical purposes.
 193     Multiple WSL environments share the same kernel and services
 194     should generally behave like when being run in a container.</para>
 195   </refsect1>
 196
 197   <refsect1>
 198     <title>Options</title>
 199
 200     <para>The following options are understood:</para>
 201
 202     <variablelist>
 203       <varlistentry>
 204         <term><option>-c</option></term>
 205         <term><option>--container</option></term>
 206
 207         <listitem><para>Only detects container virtualization (i.e.
 208         shared kernel virtualization).</para></listitem>
 209       </varlistentry>
 210
 211       <varlistentry>
 212         <term><option>-v</option></term>
 213         <term><option>--vm</option></term>
 214
 215         <listitem><para>Only detects hardware virtualization.</para></listitem>
 216       </varlistentry>
 217
 218       <varlistentry>
 219         <term><option>-r</option></term>
 220         <term><option>--chroot</option></term>
 221
 222         <listitem><para>Detect whether invoked in a
 223         <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 224         environment. In this mode, no output is written, but the return
 225         value indicates whether the process was invoked in a
 226         <function>chroot()</function>
 227         environment or not.</para></listitem>
 228       </varlistentry>
 229
 230       <varlistentry>
 231         <term><option>--private-users</option></term>
 232
 233         <listitem><para>Detect whether invoked in a user namespace.  In this mode, no
 234         output is written, but the return value indicates whether the process was invoked
 235         inside of a user namespace or not. See
 236         <citerefentry project='man-pages'><refentrytitle>user_namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 237         for more information.</para></listitem>
 238       </varlistentry>
 239
 240       <varlistentry>
 241         <term><option>-q</option></term>
 242         <term><option>--quiet</option></term>
 243
 244         <listitem><para>Suppress output of the virtualization
 245         technology identifier.</para></listitem>
 246       </varlistentry>
 247
 248       <varlistentry>
 249         <term><option>--list</option></term>
 250
 251         <listitem><para>Output all currently known and detectable container and VM environments.</para></listitem>
 252       </varlistentry>
 253
 254       <xi:include href="standard-options.xml" xpointer="help" />
 255       <xi:include href="standard-options.xml" xpointer="version" />
 256     </variablelist>
 257
 258   </refsect1>
 259
 260   <refsect1>
 261     <title>Exit status</title>
 262
 263     <para>If a virtualization technology is detected, 0 is returned, a
 264     non-zero code otherwise.</para>
 265   </refsect1>
 266
 267   <refsect1>
 268     <title>See Also</title>
 269     <para>
 270       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 271       <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 272       <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 273       <citerefentry project='man-pages'><refentrytitle>namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 274     </para>
 275   </refsect1>
 276
 277 </refentry>