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.
30 This is a Docker container.
32 Status: confirmed by Charles Nguyen
36 This is Microsoft Hyper-V hypervisor.
38 Status: confirmed by RWMJ
40 =item B<ibm_power-kvm>
42 This is an IBM POWER KVM guest.
44 Status: contributed by Adrian Likins.
46 =item B<ibm_power-lpar_shared>
48 =item B<ibm_power-lpar_dedicated>
50 This is an IBM POWER LPAR (hardware partition) in either shared
53 Status: contributed by Adrian Likins.
57 This is an IBM SystemZ (or other S/390) hardware partitioning system.
58 Additional facts listed below may also be printed.
60 =item B<ibm_systemz-direct>
62 This is Linux running directly on a IBM SystemZ hardware partitioning
65 This is expected to be a highly unusual configuration - if
66 you see this result you should treat it with suspicion.
70 =item B<ibm_systemz-lpar>
72 This is Linux running directly on an LPAR on an IBM SystemZ
73 hardware partitioning system.
77 =item B<ibm_systemz-zvm>
79 This is a z/VM guest running in an LPAR on an IBM SystemZ
80 hardware partitioning system.
82 Status: confirmed by RWMJ using a Fedora guest running in z/VM
84 =item B<linux_vserver>
86 This is printed for backwards compatibility with older virt-what which
87 could not distinguish between a Linux VServer container guest and
90 =item B<linux_vserver-guest>
92 This process is running in a Linux VServer container.
94 Status: contributed by Barış Metin
96 =item B<linux_vserver-host>
98 This process is running as the Linux VServer host (VxID 0).
100 Status: contributed by Barış Metin and Elan Ruusamäe
104 This process is running in a Linux LXC container.
106 Status: contributed by Marc Fournier
110 This guest is running on the KVM hypervisor using hardware
113 Note that if the hypervisor is using software acceleration
114 you should I<not> see this, but should see the C<qemu> fact
117 Status: confirmed by RWMJ.
121 This guest is running on the KVM hypervisor using hardware
122 acceleration, and the userspace component of the hypervisor
123 is lkvm (a.k.a kvmtool).
125 Status: contributed by Andrew Jones
129 The guest appears to be running inside an OpenVZ or Virtuozzo
132 Status: contributed by Evgeniy Sokolov
136 The guest is running on an oVirt or RHEV node.
138 Status: contributed by RWMJ, not confirmed
142 The guest is running inside Parallels Virtual Platform
143 (Parallels Desktop, Parallels Server).
145 Status: contributed by Justin Clift
147 =item B<powervm_lx86>
149 The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
151 Status: data originally supplied by Jeffrey Scheel, confirmed by
152 Yufang Zhang and RWMJ
156 This is QEMU hypervisor using software emulation.
158 Note that for KVM (hardware accelerated) guests you should I<not> see
161 Status: confirmed by RWMJ.
165 This is a User-Mode Linux (UML) guest.
167 Status: contributed by Laurent Léonard
171 Some sort of virtualization appears to be present, but we are not sure
172 what it is. In some very rare corner cases where we know that
173 virtualization is hard to detect, we will try a timing attack to see
174 if certain machine instructions are running much more slowly than they
175 should be, which would indicate virtualization. In this case, the
176 generic fact C<virt> is printed.
180 This is Hitachi Virtualization Manager (HVM) Virtage
181 hardware partitioning system.
183 Status: data supplied by Bhavna Sarathy, not confirmed
187 This is a VirtualBox guest.
189 Status: contributed by Laurent Léonard
193 The guest appears to be running on Microsoft VirtualPC.
195 Status: not confirmed
199 The guest appears to be running on VMware hypervisor.
201 Status: confirmed by RWMJ
205 The guest appears to be running on Xen hypervisor.
207 Status: confirmed by RWMJ
211 This is the Xen dom0 (privileged domain).
213 Status: confirmed by RWMJ
217 This is a Xen domU (paravirtualized guest domain).
219 Status: confirmed by RWMJ
223 This is a Xen guest fully virtualized (HVM).
225 Status: confirmed by RWMJ
231 Programs that use or wrap C<virt-what> should check that the exit
232 status is 0 before they attempt to parse the output of the command.
234 A non-zero exit status indicates some error, for example, an
235 unrecognized command line argument. If the exit status is non-zero
236 then the output "facts" (if any were printed) cannot be guaranteed and
239 The exit status does I<not> have anything to do with whether the
240 program is running on baremetal or under virtualization, nor with
241 whether C<virt-what> managed detection "correctly" (which is basically
242 unknowable given the large variety of virtualization systems out there
243 and that some systems deliberately emulate others).
245 =head1 RUNNING VIRT-WHAT FROM OTHER PROGRAMS
247 C<virt-what> is designed so that you can easily run it from
248 other programs or wrap it up in a library.
250 Your program should check the exit status (see the section above).
252 Some programming languages (notably Python: issue 1652) erroneously
253 mask the C<SIGPIPE> signal and do not restore it when executing
254 subprocesses. C<virt-what> is a shell script and some shell commands
255 do not work correctly when you do this. You may see warnings from
256 C<virt-what> similar to this:
258 echo: write error: Broken pipe
260 The solution is to set the C<SIGPIPE> signal handler back to C<SIG_DFL>
261 before running C<virt-what>.
263 =head1 IMPORTANT NOTE
265 Most of the time, using this program is the I<wrong> thing to do.
266 Instead you should detect the specific features you actually want to
267 use. (As an example, if you wanted to issue Xen hypervisor commands
268 you would look for the C</proc/xen/privcmd> file).
270 However people keep asking for this, so we provide it. There are a
275 =item Bug reporting tool
277 If you think that virtualization could affect how your program runs,
278 then you might use C<virt-what> to report this in a bug reporting
281 =item Status display and monitoring tools
283 You might include this information in status and monitoring programs.
285 =item System tuning (sometimes)
287 You might use this program to tune an operating system so it runs
288 better as a virtual machine of a particular hypervisor. However if
289 installing paravirtualized drivers, it's better to check for the
290 specific features your drivers need (eg. for the presence of PCI devices).
296 L<http://people.redhat.com/~rjones/virt-what/>,
297 L<http://www.vmware.com/>,
298 L<http://www.microsoft.com/windows/products/winfamily/virtualpc>,
299 L<http://xensource.com/>,
300 L<http://bellard.org/qemu/>,
301 L<http://kvm.qumranet.com/>,
302 L<http://openvz.org/>
306 Richard W.M. Jones <rjones @ redhat . com>
310 (C) Copyright 2008-2015 Red Hat Inc.,
311 L<http://people.redhat.com/~rjones/virt-what/>
313 This program is free software; you can redistribute it and/or modify
314 it under the terms of the GNU General Public License as published by
315 the Free Software Foundation; either version 2 of the License, or
316 (at your option) any later version.
318 This program is distributed in the hope that it will be useful,
319 but WITHOUT ANY WARRANTY; without even the implied warranty of
320 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
321 GNU General Public License for more details.
323 You should have received a copy of the GNU General Public License
324 along with this program; if not, write to the Free Software
325 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
327 =head1 REPORTING BUGS
329 Bugs can be viewed on the Red Hat Bugzilla page:
330 L<https://bugzilla.redhat.com/>.
332 If you find a bug in virt-what, please follow these steps to report it:
336 =item 1. Check for existing bug reports
338 Go to L<https://bugzilla.redhat.com/> and search for similar bugs.
339 Someone may already have reported the same bug, and they may even
342 =item 2. Capture debug and error messages
346 virt-what > virt-what.log 2>&1
348 and keep I<virt-what.log>. It may contain error messages which you
349 should submit with your bug report.
351 =item 3. Get version of virt-what.
357 =item 4. Submit a bug report.
359 Go to L<https://bugzilla.redhat.com/> and enter a new bug.
360 Please describe the problem in as much detail as possible.
362 Remember to include the version numbers (step 3) and the debug
363 messages file (step 2) and as much other detail as possible.
365 =item 5. Assign the bug to rjones @ redhat.com
367 Assign or reassign the bug to B<rjones @ redhat.com> (without the
368 spaces). You can also send me an email with the bug number if you
369 want a faster response.