Virtualization is a hot topic nowadays. You will see most of the IT people (network and systems administrators) talking about Virtualization quite often. Before digging deep on what is virtualization, let’s talk a little about why we need or use virtualization as it will help us better understand the concept.
Uses of Virtualization
Virtualization technology is used to make the hardware resources expandable without having to shift the software and data from one place to another.
Virtualization is also used to lower the costs of computer hardware as multiple virtual servers can be hosted on a single server hardware.
Virtualization can be used to setup separate environments for each software application so that one application cannot interfere with the other. This is especially useful when testing a software product on different environments. Rather than dedicating a separate hardware machine, one can easily setup virtual servers on one hardware machine.
Virtualization can be used as a standardization tool. This means that we can setup one Operating System environment as a standard and then replicate the same virtual machine as many times as we want.
What is Virtualization?
According to Wikipedia:
Virtualization (Computing) is the creation of a virtual (rather than actual) version of something, such as a hardware platform, operating system, storage device, or network resources.
Let’s take a simpler example of Virtualization. If you are a frequent computer user, you should already be knowledgeable about the partitions of your hard drive. You can create more than one partition in your computer. In Windows, the partitions are named as C:\, D:\, E:\ etc. We call all the partitions as separate drives. We also know that our computer consists of only a single physical hard drive. These drives are logical partitions of the single physical hard drive. This can be termed as Virtualization as we are creating a multiple virtual versions of a single hardware.
Types of Virtualization
Virtualization is a term which can be used with wide variety of topics but the most popular subject in which Virtualization is used is Operating System Virtualization. Operating System Virtualization means that multiple Operating Systems are being run simultaneously on the same hardware. Other types of Virtualizations include Software Virtualization, Network Virtualization, Storage Virtualization and Server Virtualization.
We’ll discuss other types of Virtualization solutions some time later but in this post we will give the most popular Operating System Virtualization solutions available for Windows.
Operating System Virtualization terminology
Before we go to discuss the actual solution, let’s first get familiar with the terminology used in Operating system Virtualization.
- Host: The Operating System on which the Virtualization software solution runs is called the host.
- Guest: The Operating System which is run inside the Virtualization software is called the guest.
1. Microsoft Virtual PC
Microsoft Virtual PC, as the name implies, is a free Virtualization product from Microsoft. The latest version of Virtual PC is Virtual PC 2007. It can run almost any Operating System as a guest, but only a few hosts are supported, listed below:
- Windows Vista Business, Enterprise and Ultimate
- Windows Server 2003 Standard Edition (32-bit and 64-bit supported)
- Windows XP Professional (32-bit and 64-bit supported)
- Windows XP Tablet PC Edition
Although Virtual PC does everything which a standard Virtualization software can do, it has certain limitations. It does not have USB device support and it cannot save multiple snapshots of the Virtual machine. Other than these limitations, Virtual PC is quite fast especially if you want to install any version of Windows as a guest Operating System.
Please note that Windows XP mode in Windows 7 is just an extension of Virtual PC. It will create a preset Windows XP environment in Windows 7 so that Windows 7 users may be able to run the programs which are only supported to run on Windows XP.
VirtualBox is a Virtualization product from Oracle. The advantage of VirtualBox over Virtual PC is that VirtualBox can run on most platforms including Windows, Linux and Mac. VirtualBox is free and Open-Source. It supports resizing the guest Operating System screen according to the VirtualBox window. You need to have “scale mode” enabled for this purpose. If you click on the guest OS screen, your mouse and keyboard will be locked inside the guest OS so that you can use the keyboard and mouse in the guest OS without interrupting the host. To release the mouse and keyboard to be used in the host, just press Ctrl + left arrow key. This hotkey can be customized in VirtualBox options.
VirtualBox also comes with an extension pack which can be installed along with VirtualBox in order to get additional functionality like USB device support, remote desktop connection and PXE (network) booting capability for Intel NIC (LAN) cards.
Although VirtualBox runs in Mac OS but it has many problems and creates stability issues. So it should only be used in a home environment when Mac OS has to be used as a host Operating System. VirtualBox runs fine on Windows and Linux as hosts.
Download VirtualBox (All Operating Systems)
3. VMLite Workstation
VMLite Workstation is a Virtualization product based on VirtualBox (Open Source). It works very similar to Microsoft Virtual PC but gets rid of the limitations of Virtual PC. An interesting feature of VMLite Workstation is that it supports running of a 64-bit guest Operating System on a 32-bit host Operating System. So if you are running 32-bit Windows 7, you will be able to run 64-bit Windows XP with the help of VMLite Workstation.
As opposed to Virtual PC, VMLite supports saving of multiple live snapshots of the virtual machine. This is like versioning. If you don’t like the current version of the environment, you can always revert to a previous state using a previous snapshot saved by VMLite Workstation.
VMLite supports most of the Virtualization formats used in the industry like VMDK (VMWare), VHD (Microsoft), VDI (Sun) and HDD (Parallel).
VMLite comes with its own version of Windows XP Mode for Windows 7. It gives the same functionality as the original Windows XP mode and does not require any hardware Virtualization.
Download VMLite Workstation (Registration required to download the setup file)
4. VMWare Server
VMWare Server is a free Virtualization software from VMWare. Although its support has ended but it can still be downloaded and used for free. VMWare Server supports almost all the Operating Systems as guests or hosts but 64-bit guest OS cannot be installed on a 32-bit host. VMWare Server has support for USB devices and also supports bridged, NAT and host only network interfaces.
VMWare Server comes with administrative tools package which can be installed from the File menu. The administrative tools make it easier to communicate between the host and the guest Operating System without locking the mouse and enabling of cut, copy, paste and drag and drop operations across host and guest OS.
Other Virtualization Solutions
While researching for this article, I have come across some very useful software which may not be free but are worth a look. While free solutions can be used for home and SOHO businesses, commercial products can satisfy the needs of large enterprises. I’m listing down the software that I came across during my research:
VMWare Workstation is very similar to VMWare Server but it is still supported by VMWare.
VMWare Fusion and Parallels Desktop are the perfect but paid alternatives to VirtualBox if you are using Mac OS as host Operating System. If you are looking for a free solution for Mac OS, try Boot Camp.
QEMU is another popular Virtualization solution but I couldn’t find QEMU for Windows. The downloads are only available for Linux.
Paragon Go Virtual was another good Virtualization software but it seems to have been discontinued. It can be downloaded from Majorgeeks.
I hope this article will serve as a good guide for Virtualization software. If I have missed anything or you have suggestions about this topic, please communicate via comments below.
Note: You may also be interested in our already covered topics on MTE about Virtualization:
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