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 bhyve (FreeBSD hypervisor) guest.
32 Status: contributed by Leonardo Brondani Schenkel.
36 This is a Docker container.
38 Status: confirmed by Charles Nguyen
42 This is Microsoft Hyper-V hypervisor.
44 Status: confirmed by RWMJ
46 =item B<ibm_power-kvm>
48 This is an IBM POWER KVM guest.
50 Status: contributed by Adrian Likins.
52 =item B<ibm_power-lpar_shared>
54 =item B<ibm_power-lpar_dedicated>
56 This is an IBM POWER LPAR (hardware partition) in either shared
59 Status: contributed by Adrian Likins.
63 This is an IBM SystemZ (or other S/390) hardware partitioning system.
64 Additional facts listed below may also be printed.
66 =item B<ibm_systemz-direct>
68 This is Linux running directly on a IBM SystemZ hardware partitioning
71 This is expected to be a highly unusual configuration - if
72 you see this result you should treat it with suspicion.
76 =item B<ibm_systemz-lpar>
78 This is Linux running directly on an LPAR on an IBM SystemZ
79 hardware partitioning system.
81 Status: confirmed by Thomas Huth
83 =item B<ibm_systemz-zvm>
85 This is a z/VM guest running in an LPAR on an IBM SystemZ
86 hardware partitioning system.
88 Status: confirmed by RWMJ using a Fedora guest running in z/VM
90 =item B<ibm_systemz-kvm>
92 This is a KVM guest running on an IBM System Z hardware system.
94 Status: contributed by Thomas Huth
96 =item B<linux_vserver>
98 This is printed for backwards compatibility with older virt-what which
99 could not distinguish between a Linux VServer container guest and
102 =item B<linux_vserver-guest>
104 This process is running in a Linux VServer container.
106 Status: contributed by Barış Metin
108 =item B<linux_vserver-host>
110 This process is running as the Linux VServer host (VxID 0).
112 Status: contributed by Barış Metin and Elan Ruusamäe
116 This process is running in a Linux LXC container.
118 Status: contributed by Marc Fournier
122 This guest is running on the KVM hypervisor using hardware
125 Note that if the hypervisor is using software acceleration
126 you should I<not> see this, but should see the C<qemu> fact
129 Status: confirmed by RWMJ.
133 This guest is running on the KVM hypervisor using hardware
134 acceleration, and the userspace component of the hypervisor
135 is lkvm (a.k.a kvmtool).
137 Status: contributed by Andrew Jones
141 The guest appears to be running inside an OpenVZ or Virtuozzo
144 Status: contributed by Evgeniy Sokolov
148 The guest is running on an oVirt node.
149 (See also C<rhev> below).
151 Status: contributed by RWMJ, not confirmed
155 The guest is running inside Parallels Virtual Platform
156 (Parallels Desktop, Parallels Server).
158 Status: contributed by Justin Clift
160 =item B<powervm_lx86>
162 The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
164 Status: data originally supplied by Jeffrey Scheel, confirmed by
165 Yufang Zhang and RWMJ
169 This is QEMU hypervisor using software emulation.
171 Note that for KVM (hardware accelerated) guests you should I<not> see
174 Status: confirmed by RWMJ.
178 The guest is running on a Red Hat Enterprise Virtualization (RHEV) node.
180 Status: confirmed by RWMJ
184 This is a User-Mode Linux (UML) guest.
186 Status: contributed by Laurent Léonard
190 Some sort of virtualization appears to be present, but we are not sure
191 what it is. In some very rare corner cases where we know that
192 virtualization is hard to detect, we will try a timing attack to see
193 if certain machine instructions are running much more slowly than they
194 should be, which would indicate virtualization. In this case, the
195 generic fact C<virt> is printed.
199 This is Hitachi Virtualization Manager (HVM) Virtage
200 hardware partitioning system.
202 Status: data supplied by Bhavna Sarathy, not confirmed
206 This is a VirtualBox guest.
208 Status: contributed by Laurent Léonard
212 The guest appears to be running on Microsoft VirtualPC.
214 Status: not confirmed
218 The guest appears to be running on VMware hypervisor.
220 Status: confirmed by RWMJ
224 The guest appears to be running on Xen hypervisor.
226 Status: confirmed by RWMJ
230 This is the Xen dom0 (privileged domain).
232 Status: confirmed by RWMJ
236 This is a Xen domU (paravirtualized guest domain).
238 Status: confirmed by RWMJ
242 This is a Xen guest fully virtualized (HVM).
244 Status: confirmed by RWMJ
250 Programs that use or wrap C<virt-what> should check that the exit
251 status is 0 before they attempt to parse the output of the command.
253 A non-zero exit status indicates some error, for example, an
254 unrecognized command line argument. If the exit status is non-zero
255 then the output "facts" (if any were printed) cannot be guaranteed and
258 The exit status does I<not> have anything to do with whether the
259 program is running on baremetal or under virtualization, nor with
260 whether C<virt-what> managed detection "correctly" (which is basically
261 unknowable given the large variety of virtualization systems out there
262 and that some systems deliberately emulate others).
264 =head1 RUNNING VIRT-WHAT FROM OTHER PROGRAMS
266 C<virt-what> is designed so that you can easily run it from
267 other programs or wrap it up in a library.
269 Your program should check the exit status (see the section above).
271 Some programming languages (notably Python: issue 1652) erroneously
272 mask the C<SIGPIPE> signal and do not restore it when executing
273 subprocesses. C<virt-what> is a shell script and some shell commands
274 do not work correctly when you do this. You may see warnings from
275 C<virt-what> similar to this:
277 echo: write error: Broken pipe
279 The solution is to set the C<SIGPIPE> signal handler back to C<SIG_DFL>
280 before running C<virt-what>.
282 =head1 IMPORTANT NOTE
284 Most of the time, using this program is the I<wrong> thing to do.
285 Instead you should detect the specific features you actually want to
286 use. (As an example, if you wanted to issue Xen hypervisor commands
287 you would look for the C</proc/xen/privcmd> file).
289 However people keep asking for this, so we provide it. There are a
294 =item Bug reporting tool
296 If you think that virtualization could affect how your program runs,
297 then you might use C<virt-what> to report this in a bug reporting
300 =item Status display and monitoring tools
302 You might include this information in status and monitoring programs.
304 =item System tuning (sometimes)
306 You might use this program to tune an operating system so it runs
307 better as a virtual machine of a particular hypervisor. However if
308 installing paravirtualized drivers, it's better to check for the
309 specific features your drivers need (eg. for the presence of PCI devices).
315 L<http://people.redhat.com/~rjones/virt-what/>,
316 L<http://www.vmware.com/>,
317 L<http://www.microsoft.com/windows/products/winfamily/virtualpc>,
318 L<http://xensource.com/>,
319 L<http://bellard.org/qemu/>,
320 L<http://kvm.qumranet.com/>,
321 L<http://openvz.org/>
325 Richard W.M. Jones <rjones @ redhat . com>
329 (C) Copyright 2008-2015 Red Hat Inc.,
330 L<http://people.redhat.com/~rjones/virt-what/>
332 This program is free software; you can redistribute it and/or modify
333 it under the terms of the GNU General Public License as published by
334 the Free Software Foundation; either version 2 of the License, or
335 (at your option) any later version.
337 This program is distributed in the hope that it will be useful,
338 but WITHOUT ANY WARRANTY; without even the implied warranty of
339 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
340 GNU General Public License for more details.
342 You should have received a copy of the GNU General Public License
343 along with this program; if not, write to the Free Software
344 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
346 =head1 REPORTING BUGS
348 Bugs can be viewed on the Red Hat Bugzilla page:
349 L<https://bugzilla.redhat.com/>.
351 If you find a bug in virt-what, please follow these steps to report it:
355 =item 1. Check for existing bug reports
357 Go to L<https://bugzilla.redhat.com/> and search for similar bugs.
358 Someone may already have reported the same bug, and they may even
361 =item 2. Capture debug and error messages
365 virt-what > virt-what.log 2>&1
367 and keep I<virt-what.log>. It may contain error messages which you
368 should submit with your bug report.
370 =item 3. Get version of virt-what.
376 =item 4. Submit a bug report.
378 Go to L<https://bugzilla.redhat.com/> and enter a new bug.
379 Please describe the problem in as much detail as possible.
381 Remember to include the version numbers (step 3) and the debug
382 messages file (step 2) and as much other detail as possible.
384 =item 5. Assign the bug to rjones @ redhat.com
386 Assign or reassign the bug to B<rjones @ redhat.com> (without the
387 spaces). You can also send me an email with the bug number if you
388 want a faster response.