One often cited benefit of virtualization is the technology's ability to simplify operations and consolidate the number of servers and machines in an organization. Your administrators, however, will need to learn how to configure and maintain a virtual IT environment. Not only is there a vast amount of terminology to understand, but most virtualization products also require additional hardware or software. This requires an understanding of the many choices of available hypervisors and hardware, and how each should be properly configured.
Once a virtual environment has been created, compliance and auditing must also evolve to handle the physical and virtual systems. This means finding a way to measure resource usage and cost allocations among applications across a shared infrastructure, because serial numbers and physical locations are meaningless in the virtual world. Remember, if you can't measure what's on a virtual system, you can't obtain maximum benefit from it. Also, unless meticulous image cataloging is enforced, "image sprawl" and orphaned images can cause delays and overwhelm an IT staff. All this, not to mention the threat of possible rootkit hypervisors, adds to the burden of keeping virtualized systems secure.
Virtualization software can cause unpredictable errors, and the host is a potential single point of failure for all the instances that it hosts. Also, many software applications offer limited virtualization support. In the future, administrators will need to create an environment that preserves existing investments in such software licenses. The other challenge over the long term will be to realize the benefits of licensing models that favor virtualization. To maximize savings, you will need a full understanding of contracts and vendor license options.
Despite all of these pitfalls, the benefits of virtualization make the technology well worth considering. With virtualization, IT administrators can consolidate their physical infrastructures, preserve their investments in existing operating systems and applications, and get more from their hardware investments. As virtual environments grow, there will also be additional benefits to business continuity and capacity management strategies.
This was first published in March 2007