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 Microsoft Hyper-V hypervisor.
32 Status: confirmed by RWMJ
36 This is an IBM SystemZ (or other S/390) hardware partitioning system.
37 Additional facts listed below may also be printed.
39 =item B<ibm_systemz-direct>
41 This is Linux running directly on a IBM SystemZ hardware partitioning
44 This is expected to be a highly unusual configuration - if
45 you see this result you should treat it with suspicion.
49 =item B<ibm_systemz-lpar>
51 This is Linux running directly on an LPAR on an IBM SystemZ
52 hardware partitioning system.
56 =item B<ibm_systemz-zvm>
58 This is a z/VM guest running in an LPAR on an IBM SystemZ
59 hardware partitioning system.
61 Status: confirmed by RWMJ using a Fedora guest running in z/VM
63 =item B<linux_vserver>
65 This process is running in a Linux VServer container.
67 Status: contributed by Barış Metin
71 This guest is running on the KVM hypervisor using hardware
74 Note that if the hypervisor is using software acceleration
75 you should I<not> see this, but should see the C<qemu> fact
78 Status: confirmed by RWMJ.
82 The guest appears to be running inside an OpenVZ or Virtuozzo
85 Status: contributed by Evgeniy Sokolov
89 The guest is running inside Parallels Virtual Platform
90 (Parallels Desktop, Parallels Server).
92 Status: contributed by Justin Clift
96 The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
98 Status: data originally supplied by Jeffrey Scheel, confimed by
103 This is QEMU hypervisor using software emulation.
105 Note that for KVM (hardware accelerated) guests you should I<not> see
108 Status: confirmed by RWMJ.
112 This is a User-Mode Linux (UML) guest.
114 Status: contributed by Laurent Léonard
118 This is Hitachi Virtualization Manager (HVM) Virtage
119 hardware partitioning system.
121 Status: data supplied by Bhavna Sarathy, not confirmed
125 This is a VirtualBox guest.
127 Status: contributed by Laurent Léonard
131 The guest appears to be running on Microsoft VirtualPC.
133 Status: not confirmed
137 The guest appears to be running on VMware hypervisor.
139 Status: confirmed by RWMJ
143 The guest appears to be running on Xen hypervisor.
145 Status: confirmed by RWMJ
149 This is the Xen dom0 (privileged domain).
151 Status: confirmed by RWMJ
155 This is a Xen domU (paravirtualized guest domain).
157 Status: confirmed by RWMJ
161 This is a Xen guest fully virtualized (HVM).
163 Status: confirmed by RWMJ
169 Programs that use or wrap C<virt-what> should check that the exit
170 status is 0 before they attempt to parse the output of the command.
172 A non-zero exit status indicates some error, for example, an
173 unrecognized command line argument. If the exit status is non-zero
174 then the output "facts" (if any were printed) cannot be guaranteed and
177 The exit status does I<not> have anything to do with whether the
178 program is running on baremetal or under virtualization, nor with
179 whether C<virt-what> managed detection "correctly" (which is basically
180 unknowable given the large variety of virtualization systems out there
181 and that some systems deliberately emulate others).
183 =head1 RUNNING VIRT-WHAT FROM OTHER PROGRAMS
185 C<virt-what> is designed so that you can easily run it from
186 other programs or wrap it up in a library.
188 Your program should check the exit status (see the section above).
190 Some programming languages (notably Python: issue 1652) erroneously
191 mask the C<SIGPIPE> signal and do not restore it when executing
192 subprocesses. C<virt-what> is a shell script and some shell commands
193 do not work correctly when you do this. You may see warnings from
194 C<virt-what> similar to this:
196 echo: write error: Broken pipe
198 The solution is to set the C<SIGPIPE> signal handler back to C<SIG_DFL>
199 before running C<virt-what>.
201 =head1 IMPORTANT NOTE
203 Most of the time, using this program is the I<wrong> thing to do.
204 Instead you should detect the specific features you actually want to
205 use. (As an example, if you wanted to issue Xen hypervisor commands
206 you would look for the C</proc/xen/privcmd> file).
208 However people keep asking for this, so we provide it. There are a
213 =item Bug reporting tool
215 If you think that virtualization could affect how your program runs,
216 then you might use C<virt-what> to report this in a bug reporting
219 =item Status display and monitoring tools
221 You might include this information in status and monitoring programs.
227 L<http://people.redhat.com/~rjones/virt-what/>,
228 L<http://www.vmware.com/>,
229 L<http://www.microsoft.com/windows/products/winfamily/virtualpc>,
230 L<http://xensource.com/>,
231 L<http://bellard.org/qemu/>,
232 L<http://kvm.qumranet.com/>,
233 L<http://openvz.org/>
237 Richard W.M. Jones <rjones @ redhat . com>
241 (C) Copyright 2008-2011 Red Hat Inc.,
242 L<http://people.redhat.com/~rjones/virt-what/>
244 This program is free software; you can redistribute it and/or modify
245 it under the terms of the GNU General Public License as published by
246 the Free Software Foundation; either version 2 of the License, or
247 (at your option) any later version.
249 This program is distributed in the hope that it will be useful,
250 but WITHOUT ANY WARRANTY; without even the implied warranty of
251 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
252 GNU General Public License for more details.
254 You should have received a copy of the GNU General Public License
255 along with this program; if not, write to the Free Software
256 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
258 =head1 REPORTING BUGS
260 Bugs can be viewed on the Red Hat Bugzilla page:
261 L<https://bugzilla.redhat.com/>.
263 If you find a bug in virt-what, please follow these steps to report it:
267 =item 1. Check for existing bug reports
269 Go to L<https://bugzilla.redhat.com/> and search for similar bugs.
270 Someone may already have reported the same bug, and they may even
273 =item 2. Capture debug and error messages
277 virt-what > virt-what.log 2>&1
279 and keep I<virt-what.log>. It may contain error messages which you
280 should submit with your bug report.
282 =item 3. Get version of virt-what.
288 =item 4. Submit a bug report.
290 Go to L<https://bugzilla.redhat.com/> and enter a new bug.
291 Please describe the problem in as much detail as possible.
293 Remember to include the version numbers (step 3) and the debug
294 messages file (step 2) and as much other detail as possible.
296 =item 5. Assign the bug to rjones @ redhat.com
298 Assign or reassign the bug to B<rjones @ redhat.com> (without the
299 spaces). You can also send me an email with the bug number if you
300 want a faster response.