is there anyway to know if your supposedly fully dedicated server is really a virtually resource-shared machine? [duplicate]
Solution 1:
The virt-what script will identify many different types of hypervisors and container technologies. It's pre-packaged for most major Linux distributions (e.g. apt-get install virt-what or yum install virt-what) and its output is suitable for use in shell scripts. It correctly performs its detection from inside the virtual guest.
Current types of virtualization detected:
- hyperv Microsoft Hyper-V
- kvm Linux Kernel Virtual Machine (KVM)
- lxc Linux Containers
- openvz OpenVZ or Virtuozzo
- powervm_lx86 IBM PowerVM Lx86 Linux/x86 emulator
- qemu QEMU (unaccelerated)
- uml User-Mode Linux (UML)
- virtage Hitachi Virtualization Manager (HVM) Virtage LPAR
- virtualbox VirtualBox
- virtualpc Microsoft VirtualPC
- vmware VMware
- xen Xen
- xen-dom0 Xen dom0 (privileged domain)
- xen-domU Xen domU (paravirtualized guest domain)
- xen-hvm Xen guest fully virtualized (HVM)
The Puppet tool facter uses virt-what internally to determine the type of virtualization in use, so if you are using Puppet, you already have this installed.
Solution 2:
On Linux, it is possible to look for tell-tale signs of virtualisation depending on the type of hypervisor used. You can typically start by looking in /proc/cpuinfo for the CPU type. Some hypervisors report fake CPU types such as "QEMU Virtual CPU". If it is running VZ, you can find /proc/user_beancounters that report resource usage. With Xen, you will find a /proc/xen directory.
So, it is possible to guess if you are running under some sort of virtualisation.
Solution 3:
If you can run perl scripts (depending on your OS), there's one called imvirt which can detect quite a few based on various system info (/proc/cpuinfo, dmidecode, etc.) - it sounds like you're on ubuntu, so there are packages for Jaunty, Karmic and Lucid, or you can grab it from Sourceforge.
Solution 4:
There are things that were looked at by the antivirus companies for detecting blue pill virus variants.
Basically it's extremely hard for a VM to match the real time clock with the CPU counters. If you have access to install a driver, you should be able to put the system into no interrupts and watch the counters. If you have a virtualised system then your clock will drift in chunks when the VM is switched out by the hypervisor (which is supposedly impossible based on the interrupt bit).