Techniques/levels/Types of virtualization

Full Virtualization:
In Full Virtualization, Virtual Machine simulated enough hardware to allow unmodified guest OS to run.


  • Adeos
  • Mac-on-Linux
  • Parallels Desktop for Mac
  • Parallels Workstation
  • VMware Workstation
  • VMware Server (formerly GSX Server)
  • VirtualBox
  • Win4BSD
  • Win4Lin Pro.

Hardware-assisted virtualization

First implemented on the IBM System/370, hardware-assisted virtualization is a platform virtualization approach that enables efficient full virtualization using help from hardware capabilities, primarily from the host processors. Full virtualization is used to simulate a complete hardware environment, or virtual machine, in which an unmodified guest operating system (using the same instruction set as the host machine) executes in complete isolation. Hardware-assisted virtualization was recently (2006) added to x86 processors (Intel VT-x or AMD-V).

of virtualization platforms adapted to such hardware include

  • Linux KVM
  • VMware Workstation
  • VMware Fusion
  • Microsoft Virtual PC
  • Xen
  • Parallels Desktop for Mac
  • VirtualBox
  • Parallels Workstation.

Paravirtualization (Hypervisors)

It is a partial Virtualization, but is somehow similar to Full Virtualization. In this the guest OS needs to be modified to work. Because Guest OS communicates with Physical resources using special API's.


  • Xen
  • KVM

Operating System Level Virtualization (VE's Containers):
In OS Level Virtualization a physical server is virtualized at the operating system level, enabling multiple isolated and secure virtualized servers to run on a single physical server. The "guest" OS environments share the same OS as the host system – i.e. the same OS kernel is used to implement the "guest" environments. Applications running in a given "guest" environment view it as a stand-alone system.


  • Solaris Containers
  • OpenVZ
  • Linux-VServer
  • AIX Workload Partitions
  • Parallels Virtuozzo Containers (Based on openVZ)
  • iCore Virtual Accounts.