How to determine Linux guest VM virtualization technology
I
have a cloud-based virtual machine running Ubuntu and CentOS Linux server. It may or may not be virtualized. How do I determine what kind of virtualization technology (VMWARE/ KVM/ XEN/ VirtualBox/ Container/ lxc/Hyper-V etc.) a Linux guest system running on? How do I find out the virtualization type of a CentOS 7 Linux VPS?
You need to use the virt-what program (shell script) to detect the type of virtualization being used (or none at all if we’re running on bare-metal). It prints out one of more lines each being a ‘fact’ about the virtualization.
Install virt-what on Debian or Ubuntu Linux VM
$ sudo apt-get install virt-what
OR
$ sudo apt install virt-what
Fig.01: Debian/Ubuntu Linux install virt-what command
Install virt-what on RHEL/CentOS/Scientific Linux VM
$ sudo yum install virt-what
Fig.02: Fedora/RHEL/CentOS Linux install virt-what command
Install virt-what on Fedora Linux VM
$ sudo dnf install virt-what
Check if your remote server runs in virtual environment
Simply type the following command:
$ sudo virt-what
xen
xen-domU
Another output:
$ sudo virt-what
kvm
Another output:
$ sudo virt-what
lxc
Other possible values
hyperv : This is Microsoft Hyper-V hypervisor.
parallels : The guest is running inside Parallels Virtual Platform (Parallels Desktop, Parallels Server).
powervm_lx86 : The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
qemu : This is QEMU hypervisor using software emulation.
virtualpc : The guest appears to be running on Microsoft VirtualPC.
xen-hvm : This is a Xen guest fully virtualized (HVM).
uml : This is a User-Mode Linux (UML) guest.
openvz : The guest appears to be running inside an OpenVZ or Virtuozzo container.
linux_vserver : This process is running in a Linux VServer container.
ibm_systemz : This is an IBM SystemZ (or other S/390) hardware partitioning system.
If nothing is printed, 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. For more info see virt-what – detect if we are running in a virtual machine and here is the source code of the script:
#!/bin/bash –
# virt-what. Generated from virt-what.in by configure.
# Copyright (C) 2008-2011 Red Hat Inc.
# Do not allow unset variables, and set defaults.
set -u
root=
skip_qemu_kvm=false
VERSION= 1.13
function fail {
echo virt-what: $1 >&2
exit 1
}
function usage {
echo virt-what [options]
echo Options:
echo –help Display this help
echo –version Display version and exit
exit 0
}
# Handle the command line arguments, if any.
TEMP=$(getopt -o v –long help –long version –long test-root: -n virt-what — $@ )
if [ $? != 0 ]; then exit 1; fi
eval set — $TEMP
while true; do
case $1 in
–help) usage ;;
–test-root)
# Deliberately undocumented: used for make check .
root= $2
shift 2
;;
-v|–version) echo $VERSION ; exit 0 ;;
–) shift; break ;;
*) fail internal error ($1) ;;
esac
done
# Add /sbin and /usr/sbin to the path so we can find system
# binaries like dmicode.
# Add /usr/libexec to the path so we can find the helper binary.
prefix=/usr
exec_prefix=${prefix}
PATH= ${root}${prefix}/lib/virt-what:${root}/sbin:${root}/usr/sbin:${PATH}
# Check we re running as root.
if [ x$root = x ] && [ $EUID -ne 0 ]; then
fail this script must be run as root
fi
# Many fullvirt hypervisors give an indication through CPUID. Use the
# helper program to get this information.
cpuid=$(virt-what-cpuid-helper)
# Check for various products in the BIOS information.
# Note that dmidecode doesn t exist on non-PC architectures. On these,
# this will return an error which is ignored (error message redirected
# into $dmi variable).
dmi=$(LANG=C dmidecode 2>&1)
# Architecture.
# Note for the purpose of testing, we only call uname with -p option.
arch=$(uname -p)
# Check for VMware.
# cpuid check added by Chetan Loke.
if [ $cpuid = VMwareVMware ]; then
echo vmware
elif echo $dmi | grep -q Manufacturer: VMware ; then
echo vmware
fi
# Check for Hyper-V.
# http://blogs.msdn.com/b/sqlosteam/archive/2010/10/30/is-this-real-the-metaphysics-of-hardware-virtualization.aspx
if [ $cpuid = Microsoft Hv ]; then
echo hyperv
fi
# Check for VirtualPC.
# The negative check for cpuid is to distinguish this from Hyper-V
# which also has the same manufacturer string in the SM-BIOS data.
if [ $cpuid != Microsoft Hv ] &&
echo $dmi | grep -q Manufacturer: Microsoft Corporation ; then
echo virtualpc
fi
# Check for VirtualBox.
# Added by Laurent Léonard.
if echo $dmi | grep -q Manufacturer: innotek GmbH ; then
echo virtualbox
fi
# Check for OpenVZ / Virtuozzo.
# Added by Evgeniy Sokolov.
# /proc/vz – always exists if OpenVZ kernel is running (inside and outside
# container)
# /proc/bc – exists on node, but not inside container.
if [ -d ${root}/proc/vz -a ! -d ${root}/proc/bc ]; then
echo openvz
fi
# Check for LXC containers
# http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface
# Added by Marc Fournier
if [ -e ${root}/proc/1/environ ] &&
cat ${root}/proc/1/environ | tr \000 \n | grep -Eiq ^container= ; then
echo lxc
fi
# Check for Linux-VServer
if cat ${root}/proc/self/status | grep -q VxID: [0-9]* ; then
echo linux_vserver
fi
# Check for UML.
# Added by Laurent Léonard.
if grep -q UML ${root}/proc/cpuinfo ; then
echo uml
fi
# Check for IBM PowerVM Lx86 Linux/x86 emulator.
if grep -q ^vendor_id.*PowerVM Lx86 ${root}/proc/cpuinfo ; then
echo powervm_lx86
fi
# Check for Hitachi Virtualization Manager (HVM) Virtage logical partitioning.
if echo $dmi | grep -q Manufacturer.*HITACHI &&
echo $dmi | grep -q Product.* LPAR ; then
echo virtage
fi
# Check for IBM SystemZ.
if grep -q ^vendor_id.*IBM/S390 ${root}/proc/cpuinfo ; then
echo ibm_systemz
if [ -f ${root}/proc/sysinfo ]; then
if grep -q VM.*Control Program.*z/VM ${root}/proc/sysinfo ; then
echo ibm_systemz-zvm
elif grep -q ^LPAR ${root}/proc/sysinfo ; then
echo ibm_systemz-lpar
else
# This is unlikely to be correct.
echo ibm_systemz-direct
fi
fi
fi
# Check for Parallels.
if echo $dmi | grep -q Vendor: Parallels ; then
echo parallels
skip_qemu_kvm=true
fi
# Check for Xen.
if [ $cpuid = XenVMMXenVMM ]; then
echo xen; echo xen-hvm
skip_qemu_kvm=true
elif [ -f ${root}/proc/xen/capabilities ]; then
echo xen
if grep -q control_d ${root}/proc/xen/capabilities ; then
echo xen-dom0
else
echo xen-domU
fi
skip_qemu_kvm=true
elif [ -f ${root}/sys/hypervisor/type ] &&
grep -q xen ${root}/sys/hypervisor/type ; then
# Ordinary kernel with pv_ops. There does not seem to be
# enough information at present to tell whether this is dom0
# or domU. XXX
echo xen
elif [ $arch = ia64 ]; then
if [ -d ${root}/sys/bus/xen -a ! -d ${root}/sys/bus/xen-backend ]; then
# PV-on-HVM drivers installed in a Xen guest.
echo xen
echo xen-hvm
else
# There is no virt leaf on IA64 HVM. This is a last-ditch
# attempt to detect something is virtualized by using a
# timing attack.
virt-what-ia64-xen-rdtsc-test > /dev/null 2>&1
case $? in
0) ;; # not virtual
1) # Could be some sort of virt, or could just be a bit slow.
echo virt
esac
fi
fi
# Check for QEMU/KVM.
#
# Parallels exports KVMKVMKVM leaf, so skip this test if we ve already
# seen that it s Parallels. Xen uses QEMU as the device model, so
# skip this test if we know it is Xen.
if ! $skip_qemu_kvm ; then
if [ $cpuid = KVMKVMKVM ]; then
echo kvm
else
# XXX This is known to fail for qemu with the explicit -cpu
# option, since /proc/cpuinfo will not contain the QEMU
# string. The long term fix for this would be to export
# another CPUID leaf for non-accelerated qemu.
if grep -q QEMU ${root}/proc/cpuinfo ; then
echo qemu
fi
fi
fi
