5 virt-what - detect if we are running in a virtual machine
13 C<virt-what> is a shell script which can be used to detect if the
14 program is running in a virtual machine.
16 The program prints out a list of "facts" about the virtual machine,
17 derived from heuristics. One fact is printed per line.
19 If nothing is printed and the script exits with code 0 (no error),
20 then it can mean I<either> that the program is running on bare-metal
21 I<or> the program is running inside a type of virtual machine which we
22 don't know about or cannot detect.
32 Note that virt-what will print this fact for baremetal AWS instances,
33 which you might not consider to be true virtualization. In this case
34 other facts (eg. C<kvm> or C<xen>) would I<not> be present.
36 Status: contributed by Qi Guo, Vitaly Kuznetsov, confirmed by RWMJ.
40 This is a bhyve (FreeBSD hypervisor) guest.
42 Status: contributed by Leonardo Brondani Schenkel.
46 This is a Docker container.
48 Status: confirmed by Charles Nguyen
52 This is Microsoft Hyper-V hypervisor.
54 Status: confirmed by RWMJ
56 =item B<ibm_power-kvm>
58 This is an IBM POWER KVM guest.
60 Status: contributed by Adrian Likins.
62 =item B<ibm_power-lpar_shared>
64 =item B<ibm_power-lpar_dedicated>
66 This is an IBM POWER LPAR (hardware partition) in either shared
69 Status: contributed by Adrian Likins.
73 This is an IBM SystemZ (or other S/390) hardware partitioning system.
74 Additional facts listed below may also be printed.
76 =item B<ibm_systemz-direct>
78 This is Linux running directly on a IBM SystemZ hardware partitioning
81 This is expected to be a highly unusual configuration - if
82 you see this result you should treat it with suspicion.
86 =item B<ibm_systemz-lpar>
88 This is Linux running directly on an LPAR on an IBM SystemZ
89 hardware partitioning system.
91 Status: confirmed by Thomas Huth
93 =item B<ibm_systemz-zvm>
95 This is a z/VM guest running in an LPAR on an IBM SystemZ
96 hardware partitioning system.
98 Status: confirmed by RWMJ using a Fedora guest running in z/VM
100 =item B<ibm_systemz-kvm>
102 This is a KVM guest running on an IBM System Z hardware system.
104 Status: contributed by Thomas Huth
108 The guest appears to be running on an Linux SPARC system with
109 Oracle VM Server for SPARC (Logical Domains) support.
111 Status: contributed by Darren Kenny
113 =item B<ldoms-control>
115 The is the Oracle VM Server for SPARC (Logical Domains) control domain.
117 Status: contributed by Darren Kenny
121 The is the Oracle VM Server for SPARC (Logical Domains) guest domain.
123 Status: contributed by Darren Kenny
127 The is the Oracle VM Server for SPARC (Logical Domains) I/O domain.
129 Status: contributed by Darren Kenny
133 The is the Oracle VM Server for SPARC (Logical Domains) Root domain.
135 Status: contributed by Darren Kenny
137 =item B<linux_vserver>
139 This is printed for backwards compatibility with older virt-what which
140 could not distinguish between a Linux VServer container guest and
143 =item B<linux_vserver-guest>
145 This process is running in a Linux VServer container.
147 Status: contributed by Barış Metin
149 =item B<linux_vserver-host>
151 This process is running as the Linux VServer host (VxID 0).
153 Status: contributed by Barış Metin and Elan Ruusamäe
157 This process is running in a Linux LXC container.
159 Status: contributed by Marc Fournier
163 This guest is running on the KVM hypervisor using hardware
166 Note that if the hypervisor is using software acceleration
167 you should I<not> see this, but should see the C<qemu> fact
170 Status: confirmed by RWMJ.
174 This guest is running on the KVM hypervisor using hardware
175 acceleration, and the userspace component of the hypervisor
176 is lkvm (a.k.a kvmtool).
178 Status: contributed by Andrew Jones
182 The guest is running inside Nutanix Acropolis Hypervisor (AHV).
184 Status: confirmed by RWMJ.
188 The guest appears to be running inside an OpenVZ or Virtuozzo
191 Status: contributed by Evgeniy Sokolov
195 The guest is running on an oVirt node.
196 (See also C<rhev> below).
198 Status: contributed by RWMJ, not confirmed
202 The guest is running inside Parallels Virtual Platform
203 (Parallels Desktop, Parallels Server).
205 Status: contributed by Justin Clift
207 =item B<powervm_lx86>
209 The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
211 Status: data originally supplied by Jeffrey Scheel, confirmed by
212 Yufang Zhang and RWMJ
216 This is QEMU hypervisor using software emulation.
218 Note that for KVM (hardware accelerated) guests you should I<not> see
221 Status: confirmed by RWMJ.
225 The guest is running on a Red Hat Enterprise Virtualization (RHEV) node.
227 Status: confirmed by RWMJ
231 This is a User-Mode Linux (UML) guest.
233 Status: contributed by Laurent Léonard
237 Some sort of virtualization appears to be present, but we are not sure
238 what it is. In some very rare corner cases where we know that
239 virtualization is hard to detect, we will try a timing attack to see
240 if certain machine instructions are running much more slowly than they
241 should be, which would indicate virtualization. In this case, the
242 generic fact C<virt> is printed.
246 This is Hitachi Virtualization Manager (HVM) Virtage
247 hardware partitioning system.
249 Status: data supplied by Bhavna Sarathy, not confirmed
253 This is a VirtualBox guest.
255 Status: contributed by Laurent Léonard
259 The guest appears to be running on Microsoft VirtualPC.
261 Status: not confirmed
265 This is a vmm (OpenBSD hypervisor) guest.
267 Status: contributed by Jasper Lievisse Adriaanse.
271 The guest appears to be running on VMware hypervisor.
273 Status: confirmed by RWMJ
277 The guest appears to be running on Xen hypervisor.
279 Status: confirmed by RWMJ
283 This is the Xen dom0 (privileged domain).
285 Status: confirmed by RWMJ
289 This is a Xen domU (paravirtualized guest domain).
291 Status: confirmed by RWMJ
295 This is a Xen guest fully virtualized (HVM).
297 Status: confirmed by RWMJ
303 Programs that use or wrap C<virt-what> should check that the exit
304 status is 0 before they attempt to parse the output of the command.
306 A non-zero exit status indicates some error, for example, an
307 unrecognized command line argument. If the exit status is non-zero
308 then the output "facts" (if any were printed) cannot be guaranteed and
311 The exit status does I<not> have anything to do with whether the
312 program is running on baremetal or under virtualization, nor with
313 whether C<virt-what> managed detection "correctly" (which is basically
314 unknowable given the large variety of virtualization systems out there
315 and that some systems deliberately emulate others).
317 =head1 RUNNING VIRT-WHAT FROM OTHER PROGRAMS
319 C<virt-what> is designed so that you can easily run it from
320 other programs or wrap it up in a library.
322 Your program should check the exit status (see the section above).
324 Some programming languages (notably Python: issue 1652) erroneously
325 mask the C<SIGPIPE> signal and do not restore it when executing
326 subprocesses. C<virt-what> is a shell script and some shell commands
327 do not work correctly when you do this. You may see warnings from
328 C<virt-what> similar to this:
330 echo: write error: Broken pipe
332 The solution is to set the C<SIGPIPE> signal handler back to C<SIG_DFL>
333 before running C<virt-what>.
335 =head1 IMPORTANT NOTE
337 Most of the time, using this program is the I<wrong> thing to do.
338 Instead you should detect the specific features you actually want to
339 use. (As an example, if you wanted to issue Xen hypervisor commands
340 you would look for the C</proc/xen/privcmd> file).
342 However people keep asking for this, so we provide it. There are a
347 =item Bug reporting tool
349 If you think that virtualization could affect how your program runs,
350 then you might use C<virt-what> to report this in a bug reporting
353 =item Status display and monitoring tools
355 You might include this information in status and monitoring programs.
357 =item System tuning (sometimes)
359 You might use this program to tune an operating system so it runs
360 better as a virtual machine of a particular hypervisor. However if
361 installing paravirtualized drivers, it's better to check for the
362 specific features your drivers need (eg. for the presence of PCI devices).
368 L<http://people.redhat.com/~rjones/virt-what/>,
369 L<http://www.vmware.com/>,
370 L<http://www.microsoft.com/windows/products/winfamily/virtualpc>,
371 L<http://xensource.com/>,
372 L<http://bellard.org/qemu/>,
373 L<http://kvm.qumranet.com/>,
374 L<http://openvz.org/>
378 Richard W.M. Jones <rjones @ redhat . com>
382 (C) Copyright 2008-2015 Red Hat Inc.,
383 L<http://people.redhat.com/~rjones/virt-what/>
385 This program is free software; you can redistribute it and/or modify
386 it under the terms of the GNU General Public License as published by
387 the Free Software Foundation; either version 2 of the License, or
388 (at your option) any later version.
390 This program is distributed in the hope that it will be useful,
391 but WITHOUT ANY WARRANTY; without even the implied warranty of
392 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
393 GNU General Public License for more details.
395 You should have received a copy of the GNU General Public License
396 along with this program; if not, write to the Free Software
397 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
399 =head1 REPORTING BUGS
401 Bugs can be viewed on the Red Hat Bugzilla page:
402 L<https://bugzilla.redhat.com/>.
404 If you find a bug in virt-what, please follow these steps to report it:
408 =item 1. Check for existing bug reports
410 Go to L<https://bugzilla.redhat.com/> and search for similar bugs.
411 Someone may already have reported the same bug, and they may even
414 =item 2. Capture debug and error messages
418 virt-what > virt-what.log 2>&1
420 and keep I<virt-what.log>. It may contain error messages which you
421 should submit with your bug report.
423 =item 3. Get version of virt-what.
429 =item 4. Submit a bug report.
431 Go to L<https://bugzilla.redhat.com/> and enter a new bug.
432 Please describe the problem in as much detail as possible.
434 Remember to include the version numbers (step 3) and the debug
435 messages file (step 2) and as much other detail as possible.
437 =item 5. Assign the bug to rjones @ redhat.com
439 Assign or reassign the bug to B<rjones @ redhat.com> (without the
440 spaces). You can also send me an email with the bug number if you
441 want a faster response.