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