How to determine Linux guest VM virtualization technology

http://www.cyberciti.biz/faq/linux-determine-virtualization-technology-command

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

1. hyperv : This is Microsoft Hyper-V hypervisor.
2. parallels : The guest is running inside Parallels Virtual Platform (Parallels Desktop, Parallels Server).
3. powervm_lx86 : The guest is running inside IBM PowerVM Lx86 Linux/x86 emulator.
4. qemu : This is QEMU hypervisor using software emulation.
5. virtualpc : The guest appears to be running on Microsoft VirtualPC.
6. xen-hvm : This is a Xen guest fully virtualized (HVM).
7. uml : This is a User-Mode Linux (UML) guest.
8. openvz : The guest appears to be running inside an OpenVZ or Virtuozzo container.
9. linux_vserver : This process is running in a Linux VServer container.
10. 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