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.
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<linux_vserver>
92 This is printed for backwards compatibility with older virt-what which
93 could not distinguish between a Linux VServer container guest and
96 =item B<linux_vserver-guest>
98 This process is running in a Linux VServer container.
100 Status: contributed by Barış Metin
102 =item B<linux_vserver-host>
104 This process is running as the Linux VServer host (VxID 0).
106 Status: contributed by Barış Metin and Elan Ruusamäe
110 This process is running in a Linux LXC container.
112 Status: contributed by Marc Fournier
116 This guest is running on the KVM hypervisor using hardware
119 Note that if the hypervisor is using software acceleration
120 you should I<not> see this, but should see the C<qemu> fact
123 Status: confirmed by RWMJ.
127 This guest is running on the KVM hypervisor using hardware
128 acceleration, and the userspace component of the hypervisor
129 is lkvm (a.k.a kvmtool).
131 Status: contributed by Andrew Jones
135 The guest appears to be running inside an OpenVZ or Virtuozzo
138 Status: contributed by Evgeniy Sokolov
142 The guest is running on an oVirt node.
143 (See also C<rhev> below).
145 Status: contributed by RWMJ, not confirmed
149 The guest is running inside Parallels Virtual Platform
150 (Parallels Desktop, Parallels Server).
152 Status: contributed by Justin Clift
154 =item B<powervm_lx86>
156 The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
158 Status: data originally supplied by Jeffrey Scheel, confirmed by
159 Yufang Zhang and RWMJ
163 This is QEMU hypervisor using software emulation.
165 Note that for KVM (hardware accelerated) guests you should I<not> see
168 Status: confirmed by RWMJ.
172 The guest is running on a Red Hat Enterprise Virtualization (RHEV) node.
174 Status: confirmed by RWMJ
178 This is a User-Mode Linux (UML) guest.
180 Status: contributed by Laurent Léonard
184 Some sort of virtualization appears to be present, but we are not sure
185 what it is. In some very rare corner cases where we know that
186 virtualization is hard to detect, we will try a timing attack to see
187 if certain machine instructions are running much more slowly than they
188 should be, which would indicate virtualization. In this case, the
189 generic fact C<virt> is printed.
193 This is Hitachi Virtualization Manager (HVM) Virtage
194 hardware partitioning system.
196 Status: data supplied by Bhavna Sarathy, not confirmed
200 This is a VirtualBox guest.
202 Status: contributed by Laurent Léonard
206 The guest appears to be running on Microsoft VirtualPC.
208 Status: not confirmed
212 The guest appears to be running on VMware hypervisor.
214 Status: confirmed by RWMJ
218 The guest appears to be running on Xen hypervisor.
220 Status: confirmed by RWMJ
224 This is the Xen dom0 (privileged domain).
226 Status: confirmed by RWMJ
230 This is a Xen domU (paravirtualized guest domain).
232 Status: confirmed by RWMJ
236 This is a Xen guest fully virtualized (HVM).
238 Status: confirmed by RWMJ
244 Programs that use or wrap C<virt-what> should check that the exit
245 status is 0 before they attempt to parse the output of the command.
247 A non-zero exit status indicates some error, for example, an
248 unrecognized command line argument. If the exit status is non-zero
249 then the output "facts" (if any were printed) cannot be guaranteed and
252 The exit status does I<not> have anything to do with whether the
253 program is running on baremetal or under virtualization, nor with
254 whether C<virt-what> managed detection "correctly" (which is basically
255 unknowable given the large variety of virtualization systems out there
256 and that some systems deliberately emulate others).
258 =head1 RUNNING VIRT-WHAT FROM OTHER PROGRAMS
260 C<virt-what> is designed so that you can easily run it from
261 other programs or wrap it up in a library.
263 Your program should check the exit status (see the section above).
265 Some programming languages (notably Python: issue 1652) erroneously
266 mask the C<SIGPIPE> signal and do not restore it when executing
267 subprocesses. C<virt-what> is a shell script and some shell commands
268 do not work correctly when you do this. You may see warnings from
269 C<virt-what> similar to this:
271 echo: write error: Broken pipe
273 The solution is to set the C<SIGPIPE> signal handler back to C<SIG_DFL>
274 before running C<virt-what>.
276 =head1 IMPORTANT NOTE
278 Most of the time, using this program is the I<wrong> thing to do.
279 Instead you should detect the specific features you actually want to
280 use. (As an example, if you wanted to issue Xen hypervisor commands
281 you would look for the C</proc/xen/privcmd> file).
283 However people keep asking for this, so we provide it. There are a
288 =item Bug reporting tool
290 If you think that virtualization could affect how your program runs,
291 then you might use C<virt-what> to report this in a bug reporting
294 =item Status display and monitoring tools
296 You might include this information in status and monitoring programs.
298 =item System tuning (sometimes)
300 You might use this program to tune an operating system so it runs
301 better as a virtual machine of a particular hypervisor. However if
302 installing paravirtualized drivers, it's better to check for the
303 specific features your drivers need (eg. for the presence of PCI devices).
309 L<http://people.redhat.com/~rjones/virt-what/>,
310 L<http://www.vmware.com/>,
311 L<http://www.microsoft.com/windows/products/winfamily/virtualpc>,
312 L<http://xensource.com/>,
313 L<http://bellard.org/qemu/>,
314 L<http://kvm.qumranet.com/>,
315 L<http://openvz.org/>
319 Richard W.M. Jones <rjones @ redhat . com>
323 (C) Copyright 2008-2015 Red Hat Inc.,
324 L<http://people.redhat.com/~rjones/virt-what/>
326 This program is free software; you can redistribute it and/or modify
327 it under the terms of the GNU General Public License as published by
328 the Free Software Foundation; either version 2 of the License, or
329 (at your option) any later version.
331 This program is distributed in the hope that it will be useful,
332 but WITHOUT ANY WARRANTY; without even the implied warranty of
333 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
334 GNU General Public License for more details.
336 You should have received a copy of the GNU General Public License
337 along with this program; if not, write to the Free Software
338 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
340 =head1 REPORTING BUGS
342 Bugs can be viewed on the Red Hat Bugzilla page:
343 L<https://bugzilla.redhat.com/>.
345 If you find a bug in virt-what, please follow these steps to report it:
349 =item 1. Check for existing bug reports
351 Go to L<https://bugzilla.redhat.com/> and search for similar bugs.
352 Someone may already have reported the same bug, and they may even
355 =item 2. Capture debug and error messages
359 virt-what > virt-what.log 2>&1
361 and keep I<virt-what.log>. It may contain error messages which you
362 should submit with your bug report.
364 =item 3. Get version of virt-what.
370 =item 4. Submit a bug report.
372 Go to L<https://bugzilla.redhat.com/> and enter a new bug.
373 Please describe the problem in as much detail as possible.
375 Remember to include the version numbers (step 3) and the debug
376 messages file (step 2) and as much other detail as possible.
378 =item 5. Assign the bug to rjones @ redhat.com
380 Assign or reassign the bug to B<rjones @ redhat.com> (without the
381 spaces). You can also send me an email with the bug number if you
382 want a faster response.