VIRT-WHAT(1) Virtualization Support VIRT-WHAT(1)NAMEvirt-what - detect if we are running in a virtual machine
SUMMARYvirt-what [options]
DESCRIPTION
"virt-what" is a shell script which can be used to detect if the
program is running in a virtual machine.
The program prints out a list of "facts" about the virtual machine,
derived from heuristics. One fact is printed per line.
If nothing is printed and the script exits with code 0 (no error), then
it can mean either that the program is running on bare-metal or the
program is running inside a type of virtual machine which we don't know
about or cannot detect.
FACTS
hyperv
This is Microsoft Hyper-V hypervisor.
Status: confirmed by RWMJ
ibm_systemz
This is an IBM SystemZ (or other S/390) hardware partitioning
system. Additional facts listed below may also be printed.
ibm_systemz-direct
This is Linux running directly on a IBM SystemZ hardware
partitioning system.
This is expected to be a highly unusual configuration - if you see
this result you should treat it with suspicion.
Status: not confirmed
ibm_systemz-lpar
This is Linux running directly on an LPAR on an IBM SystemZ
hardware partitioning system.
Status: not confirmed
ibm_systemz-zvm
This is a z/VM guest running in an LPAR on an IBM SystemZ hardware
partitioning system.
Status: confirmed by RWMJ using a Fedora guest running in z/VM
linux_vserver
This process is running in a Linux VServer container.
Status: contributed by BarXX Metin
kvm This guest is running on the KVM hypervisor using hardware
acceleration.
Note that if the hypervisor is using software acceleration you
should not see this, but should see the "qemu" fact instead.
Status: confirmed by RWMJ.
openvz
The guest appears to be running inside an OpenVZ or Virtuozzo
container.
Status: contributed by Evgeniy Sokolov
parallels
The guest is running inside Parallels Virtual Platform (Parallels
Desktop, Parallels Server).
Status: contributed by Justin Clift
powervm_lx86
The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
Status: data originally supplied by Jeffrey Scheel, confimed by
Yufang Zhang and RWMJ
qemu
This is QEMU hypervisor using software emulation.
Note that for KVM (hardware accelerated) guests you should not see
this.
Status: confirmed by RWMJ.
uml This is a User-Mode Linux (UML) guest.
Status: contributed by Laurent Leonard
virt
Some sort of virtualization appears to be present, but we are not
sure what it is. In some very rare corner cases where we know that
virtualization is hard to detect, we will try a timing attack to
see if certain machine instructions are running much more slowly
than they should be, which would indicate virtualization. In this
case, the generic fact "virt" is printed.
virtage
This is Hitachi Virtualization Manager (HVM) Virtage hardware
partitioning system.
Status: data supplied by Bhavna Sarathy, not confirmed
virtualbox
This is a VirtualBox guest.
Status: contributed by Laurent Leonard
virtualpc
The guest appears to be running on Microsoft VirtualPC.
Status: not confirmed
vmware
The guest appears to be running on VMware hypervisor.
Status: confirmed by RWMJ
xen The guest appears to be running on Xen hypervisor.
Status: confirmed by RWMJ
xen-dom0
This is the Xen dom0 (privileged domain).
Status: confirmed by RWMJ
xen-domU
This is a Xen domU (paravirtualized guest domain).
Status: confirmed by RWMJ
xen-hvm
This is a Xen guest fully virtualized (HVM).
Status: confirmed by RWMJ
EXIT STATUS
Programs that use or wrap "virt-what" should check that the exit status
is 0 before they attempt to parse the output of the command.
A non-zero exit status indicates some error, for example, an
unrecognized command line argument. If the exit status is non-zero
then the output "facts" (if any were printed) cannot be guaranteed and
should be ignored.
The exit status does not have anything to do with whether the program
is running on baremetal or under virtualization, nor with whether
"virt-what" managed detection "correctly" (which is basically
unknowable given the large variety of virtualization systems out there
and that some systems deliberately emulate others).
RUNNING VIRT-WHAT FROM OTHER PROGRAMS
"virt-what" is designed so that you can easily run it from other
programs or wrap it up in a library.
Your program should check the exit status (see the section above).
Some programming languages (notably Python: issue 1652) erroneously
mask the "SIGPIPE" signal and do not restore it when executing
subprocesses. "virt-what" is a shell script and some shell commands do
not work correctly when you do this. You may see warnings from
"virt-what" similar to this:
echo: write error: Broken pipe
The solution is to set the "SIGPIPE" signal handler back to "SIG_DFL"
before running "virt-what".
IMPORTANT NOTE
Most of the time, using this program is the wrong thing to do. Instead
you should detect the specific features you actually want to use. (As
an example, if you wanted to issue Xen hypervisor commands you would
look for the "/proc/xen/privcmd" file).
However people keep asking for this, so we provide it. There are a few
legitimate uses:
Bug reporting tool
If you think that virtualization could affect how your program
runs, then you might use "virt-what" to report this in a bug
reporting tool.
Status display and monitoring tools
You might include this information in status and monitoring
programs.
SEE ALSO
<http://people.redhat.com/~rjones/virt-what/>,
<http://www.vmware.com/>,
<http://www.microsoft.com/windows/products/winfamily/virtualpc>,
<http://xensource.com/>, <http://bellard.org/qemu/>,
<http://kvm.qumranet.com/>, <http://openvz.org/>
AUTHORS
Richard W.M. Jones <rjones @ redhat . com>
COPYRIGHT
(C) Copyright 2008-2011 Red Hat Inc.,
<http://people.redhat.com/~rjones/virt-what/>
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
675 Mass Ave, Cambridge, MA 02139, USA.
REPORTING BUGS
Bugs can be viewed on the Red Hat Bugzilla page:
<https://bugzilla.redhat.com/>.
If you find a bug in virt-what, please follow these steps to report it:
1. Check for existing bug reports
Go to <https://bugzilla.redhat.com/> and search for similar bugs.
Someone may already have reported the same bug, and they may even
have fixed it.
2. Capture debug and error messages
Run
virt-what > virt-what.log 2>&1
and keep virt-what.log. It may contain error messages which you
should submit with your bug report.
3. Get version of virt-what.
Run
virt-what--version
4. Submit a bug report.
Go to <https://bugzilla.redhat.com/> and enter a new bug. Please
describe the problem in as much detail as possible.
Remember to include the version numbers (step 3) and the debug
messages file (step 2) and as much other detail as possible.
5. Assign the bug to rjones @ redhat.com
Assign or reassign the bug to rjones @ redhat.com (without the
spaces). You can also send me an email with the bug number if you
want a faster response.
virt-what-1.11 2011-05-26 VIRT-WHAT(1)
