virt-what - detect if we are running in a virtual machine
"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.
- aws
- Amazon Web Services.
Note that virt-what will print this fact for baremetal AWS
instances, which you might not consider to be true virtualization. In
this case other facts (eg. "kvm" or
"xen") would not be
present.
Status: contributed by Qi Guo, Vitaly Kuznetsov, confirmed by
RWMJ.
- bhyve
- This is a bhyve (FreeBSD hypervisor) guest.
Status: contributed by Leonardo Brondani Schenkel.
- docker
- This is a Docker container.
Status: confirmed by Charles Nguyen
- hyperv
- This is Microsoft Hyper-V hypervisor.
Status: confirmed by RWMJ
- ibm_power-kvm
- This is an IBM POWER KVM guest.
Status: contributed by Adrian Likins.
- ibm_power-lpar_shared
- ibm_power-lpar_dedicated
- This is an IBM POWER LPAR (hardware partition) in either shared or
dedicated mode.
Status: contributed by Adrian Likins.
- 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: confirmed by Thomas Huth
- 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
- ibm_systemz-kvm
- This is a KVM guest running on an IBM System Z hardware system.
Status: contributed by Thomas Huth
- ldoms
- The guest appears to be running on an Linux SPARC system with Oracle VM
Server for SPARC (Logical Domains) support.
Status: contributed by Darren Kenny
- ldoms-control
- The is the Oracle VM Server for SPARC (Logical Domains) control domain.
Status: contributed by Darren Kenny
- ldoms-guest
- The is the Oracle VM Server for SPARC (Logical Domains) guest domain.
Status: contributed by Darren Kenny
- ldoms-io
- The is the Oracle VM Server for SPARC (Logical Domains) I/O domain.
Status: contributed by Darren Kenny
- ldoms-root
- The is the Oracle VM Server for SPARC (Logical Domains) Root domain.
Status: contributed by Darren Kenny
- linux_vserver
- This is printed for backwards compatibility with older virt-what which
could not distinguish between a Linux VServer container guest and
host.
- linux_vserver-guest
- This process is running in a Linux VServer container.
Status: contributed by BarXX Metin
- linux_vserver-host
- This process is running as the Linux VServer host (VxID 0).
Status: contributed by BarXX Metin and Elan Ruusamaee
- lxc
- This process is running in a Linux LXC container.
Status: contributed by Marc Fournier
- 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.
- lkvm
- This guest is running on the KVM hypervisor using hardware acceleration,
and the userspace component of the hypervisor is lkvm (a.k.a kvmtool).
Status: contributed by Andrew Jones
- nutanix_ahv
- The guest is running inside Nutanix Acropolis Hypervisor (AHV).
Status: confirmed by RWMJ.
- openvz
- The guest appears to be running inside an OpenVZ or Virtuozzo container.
Status: contributed by Evgeniy Sokolov
- ovirt
- The guest is running on an oVirt node. (See also
"rhev" below).
Status: contributed by RWMJ, not confirmed
- parallels
- The guest is running inside Parallels Virtual Platform (Parallels Desktop,
Parallels Server).
Status: contributed by Justin Clift
- podman
- This is a Podman container.
Status: contributed by Jordan Webb
- powervm_lx86
- The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
Status: data originally supplied by Jeffrey Scheel, confirmed
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.
- rhev
- The guest is running on a Red Hat Enterprise Virtualization (RHEV) node.
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
- vmm
- This is a vmm (OpenBSD hypervisor) guest.
Status: contributed by Jasper Lievisse Adriaanse.
- 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
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).
"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".
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.
- System tuning (sometimes)
- You might use this program to tune an operating system so it runs better
as a virtual machine of a particular hypervisor. However if installing
paravirtualized drivers, it's better to check for the specific features
your drivers need (eg. for the presence of PCI devices).
<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/>
Richard W.M. Jones <rjones @ redhat . com>
(C) Copyright 2008-2015 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.
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.