What's the Best Approach to Infrastructure Virtualization?

As the others have stated, there are many considerations when assessing virtualization and cloud-based infrastructure solutions. From simple, high-level technical point of view - assuming you have substantial idle capacity on servers, you can save hardware, power and cooling costs and in doing so, leverage existing resources to support future business growth. Support, software and other "care and feeding" costs do not go away so consolidation may be another option to consider. In fact, software costs may go up on virtualized systems depending on the terms of your agreements. Applications may not perform as well because there is layer of management overhead added to the server infrastructure. So yes, you can reduce costs but there may be a performance price to pay.

You need to look at each individual IT service to determine if it plays well in a virtualized environment. Generally I/O intensive applications do not perform as well because of the additional overhead but may be acceptable if it is background job with no stringent deadlines. Being on the same machine, applications may now vie for the same resources at the same time, causing performance degradation. You also need to assess what it means to the business if a particular server goes down. Remember, now you may have multiple applications running on the same device. Applying maintenance and maintenance windows are another consideration since you may need to take multiple images down at same time. The use of analytic modeling may help you assess the impacts of the different virtualization scenarios.

As far as cloud, you have the same technical issues plus the fact that your IT resources are at the end of a telecommunications line instead of on site. The most common issue I am seeing is that the business was used to things running at LAN speeds and now they are running at substantially lower network speeds. Although the "pay-per-drink" concept is appealing to many, contractual issues also come into play and if not careful, could lock you into something that sometime in the future could be a detriment to business growth.

There is a lot for you to think about. In all the hype, they rarely tell you there is a lot of homework up front to ensure the end result works in a way that satisfies your business needs. Good luck with your research.