What is Virtualization and Why do I Care?

Virtualization is perhaps the “hottest” topic in technology these days, offering a wide range of benefits.  Although there are many things you can virtualize – servers, desktop operating systems, applications, application presentation, storage, and personalization – most people start with server virtualization.

 

Server virtualization provides a number of significant benefits.  The most obvious is reduced hardware costs – instead of purchasing 4 or more new servers, you can purchase one server with extra memory and disk space (or networked storage), and run all of these applications, isolated logically from each other, on one piece of hardware.  This is possible because of the sharp increase in computer hardware power – most new servers you buy have 2-4 cores per processor (think of a core as a brain, so a quad core system is two brains in one head) and having two or more processors is fairly inexpensive, so it is easy to buy servers with 8+ cores of CPU power fairly inexpensively.  Running just Windows and a single program on such a server severely under-utilizes the hardware.  With virtualization, the hardware is more fully utilized, and there are significant reductions in power consumption, space consumption and cooling requirements from server virtualization. 

 

Virtualization essentially breaks the one-to-one relationship between hardware and software.  We are used to buying a computer or server, and running one copy of Windows (or another operating system) on the computer, then we install our applications.  Virtualization allows a server to run multiple copies of Windows.  This is mainly done by running a “hypervisor” on top of the hardware – the hypervisor then manages hardware access and sharing for the multiple instances of Windows, just as Windows today allows multiple software programs to run at once on the same computer.

 

Furthermore, by virtualizing the server operating system, we separate it from the hardware, making it portable – essentially, each server becomes one big disk file that can be copied.  Servers can now be moved from one piece of hardware to another, either manually or automated, to create load balancing, high availability and even disaster recovery, or just providing more flexibility.  These are features that the more advanced versions of VMware and Citrix XenServer, as well as Microsoft Windows Server 2008 Enterprise Edition with Cluster Services, provide (at a higher cost), either in full or with additional software.

 

This is why SANs (“Storage Area Networks”) are complementary to virtualization – by connecting your servers to shared storage on a SAN, virtual machines can run on any of the connected servers, or be moved between them (even while they are running).  Although SANs have been prohibitively expensive for smaller businesses in the past, older FIbre Channel technology is being replaced by iSCSI (which uses regular Ethernet cables, switches and network cards), cutting the cost of the infrastructure to 1/5 or 1/10 of prior costs.  And, by centralizing your storage you can allocate it more efficiently between servers and functions.  Finally, if your servers are virtualized and stored on the SAN, then they can be replicated (copied) to other SANs along with your data, including to another location – this is a great disaster recovery solution!

 

Although server virtualization was pioneered by VMware, there are several solutions available, including from Microsoft and Citrix.  Virtualization even has an “open source” hypervisor, Xen, just as Linux provides an open source operating system platform.  Virtualization is becoming increasingly common and the cost is coming down because of increasing hardware power, Microsoft’s entry into the market (they’re giving away their Hyper-V hypervisor as part of Windows Server 2008) and the inclusion of all three major hypervisors directly on the system boards of many new servers, which are virtualization-ready with special chipsets.

 

There are a lot of other ways you can approach virtualization, some of which you may already be doing today.  Just as you can virtualize servers, you can also virtualize desktops – instead of running 4-8 server operating systems on one server, you can run 30-50 Windows desktops – with the benefit of centralized management and standardization.  This is an area of huge potential for cost savings, security improvement and increased agility, particularly for mid-sized businesses.  To do this, you also need to virtualize applications – separating them from each other so they can be easily deployed without the traditional problems of programs being dependent on each other and one program “breaking” another with changes.  Traditional tools like Windows Group Policy (centralized control over policy settings on your PCs) and Citrix/Terminal Services (“thin client”) are also forms of virtualization, and storage on a SAN can also be virtualized to allow for easier allocation and management of space (some vendors also call this “Thin Provisioning,” which requires virtualizing storage from the underlying physical disks).  So virtualization can mean a lot of things to different people, depending on where you are focused.

There’s a lot to consider and plan for here – what’s the next step?  Consider bringing in a qualified reseller/partner company that can do an assessment of your organization and help you evaluate how virtualization can benefit your organization, and help you plan and execute a project to begin the process.  Typically the ROIs can be significant, particularly for companies with a lot of older hardware, but the flexibility gains and “softer” benefits can be significant as well.   This requires a bit of a paradigm shift as you need to let go of older ways of thinking about technology, but once you do so the benefits can be significant.  It’s a bit of a journey, but well worth the effort!

 

Neil Rosenberg is President and CEO of Quality Technology Solutions, a Microsoft and Citrix Gold Partner and VMware Enterprise Partner located in Morris Plains NJ.  QTS helps businesses implement and support new technologies and helps to implement Worry-Free Network solutions.  Mr. Rosenberg can be reached at nrosenberg@QTSnet.com.

QTS regularly runs seminars on virtualization and other IT topics – for more information, visit www.QTSnet.com/events or subscribe to QTS’ QuikNews email newsletter.