Tech's Corner

What is Virtualization?

 

Virtualization is a concept used in computing in which a “Logical” or “Virtual” device is created which is abstracted from the actual hardware.  Some familiar examples of hardware abstraction include:

 

  • Hard Drive Storage:  A single physical hard drive may be divided into several partitions, each of which is a  “virtual drive”, appearing as a different drive letter to the user.
  • RAID Arrays:  In a RAID Array, several physical hard drives are joined together to appear as one or more partitions.  While they appear as normal hard drives to the Operating System, the data from one “drive” is split between two or more physical hard drives, with multiple copies stored for emergency fail-over.
  • Operating Systems:  An Operating System provides a layer of abstraction from the many different models of computers and combinations of hardware available.  This allows application developers to write programs which run on the Operating System, rather than having to write a different program for every different type of computer.
  • Terminal Services:  When a user connects through a remote desktop client into a Terminal Server, all work that they do within that session takes place on a “Virtual Desktop”, with storage and processing taking place at the server, and not in the local machine.
  • Web-Based Applications:  Applications which are delivered over the web make the computer hardware in use irrelevant – the Web Browser serves a similar role as an Operating System, allowing an application to be accessed from any device with a compatible Web Browser.

 

The recent wave of interest in Virtualization in particular uses the local resources of the computer  In particular, the focus of this recent wave of virtualization technologies is on the Server and Application Virtualization fronts:

 

  • Server Virtualization:  Creating Virtual Servers allows multiple servers to be run on the same server hardware, servers to easily be moved to different hardware, and increases options for server fail-over and load-balancing, as well as drastically reducing the complexity of backup and restoration.
  • Application Virtualization:  Running applications within a “guest machine”, a virtual computer running on local hardware.  The difference from Terminal Services is that this Virtual Computer uses the local computer’s memory, processor and other resources, rather than running entirely on a server.

 

Exploring Virtualization

 

There are many different Virtualization options available, from VMware’s line of products, to Parallels for Mac OS and Microsoft’s Virtual PC and Virtual Server, which was recently released as Virtual Server 2005 R2, and is now offering pre-configured “Virtual Hard Drives” or VHD’s for IT professionals to evaluate and train on – current VHDs available include Windows Server 2003 R2, Exchange Server 2007, and SQL Server 2005.  Each VHD is an image you can download and boot up with a fully-functioning server environment to test and explore.

 

Whether to test a new technology before rolling it out, or just to get some experience on the latest operating system without having to build out a whole test network, Microsoft Virtual PC and Virtual Server are excellent tools to bring you real hands-on experience with a minimal investment of time and hardware.

 

Getting Hands On - Microsoft Virtual PC

 

Virtual PC 2007 is currently available for free download and includes compatibility with Windows Vista.  Upon installing it on your workstation, it creates a bootable computer which runs in a window.  From here, you can install the OS of your choice, including any version of Windows, and any x86 release of Linux.  While performance is not as fast as a natively-running computer, with a fairly recent desktop, you can easily run multiple, simultaneous Virtual PC’s.  For example, if you wanted to test an application, a new Operating System, or the effects of a group policy on several workstations of different configurations, you could boot up a virtual server and an image for each of the three PC’s, and apply the changes in real-time to see the results.  Each Virtual Machine is also fully functioning as a network device, with its own IP address and settings – you can test the network operation of different servers very easily without needing to prepare multiple test servers.

 

Another great thing about Virtual PC is the capability of storing workstation and server images as a “snapshot” environment.  For example, you could store a snapshot of a freshly installed Windows 2003 Server, then make changes, such as installing applications, then store that as a separate image.  Now if you want to revert back at any time either to the clean server installation, or the newly installed application, it’s as easy as choosing that snapshot and booting up a VPC session – no more reformatting and reinstalling when a new app doesn’t behave quite the way it should.  You can also take any image and bring it up on a Virtual PC installed on another computer or server – your virtual machines are completely portable.  These snapshots are a preview of how virtualization can serve to aid in the backup and recovery process.

 

The Power of Virtualization

 

Virtual PC is a great way to get a sample of the capabilities and flexibility of virtualization.  Some possible implementations would include:

 

  • Creating Virtual PC images for lab PC’s, to provide an environment which does not have to be “locked down”, but can easily revert to original settings.
  • Using Virtual Servers and PC’s to test application behavior with different Operating Systems.
  • Consolidating multiple servers onto a single hardware platform, and providing advanced redundancy and disaster recovery options.
  • Creating an environment in which complete server functions and configurations can easily be transported between unlike hardware.

 

With Intel and AMD building acceleration for virtualization into new lines of processors, and an explosion in the available software virtualization products, it seems to be a technology that is coming to maturity.  Many large corporations have already adopted these technologies on the basis of cost savings and flexibility, and the advantages in educational environments are undeniable.  With both Microsoft Virtual PC and VMware Workstation available as free downloads, there is ample opportunity to get familiar with virtualization and it is a great time to start thinking about what it can do for you.

 

Microsoft Virtual PC 2007 is available as a free download from Microsoft at http://www.microsoft.com/windows/products/winfamily/virtualpc/default.mspx

 

 

Microsoft Virtual Server is also available as a free download at http://www.microsoft.com/windowsserversystem/virtualserver/software/default.mspx

 

 

Virtual Hard Disks (“VHD’s”)  for evaluation can be downloaded at http://www.microsoft.com/downloads/results.aspx?pocId=&freetext=msvhds&DisplayLang=en

 

VMware Workstation can be downloaded from:

http://vmware.com/download/ws/

 

If you are interested in more information on Vitualization, please contact Carl Jeanniton [cjeannit@wsboces.org] or 631 595-6811, Penny Notarnicola [pnotarni@wsboces.org] or 631 595-6831.