In a rapidly changing business environment, delays caused by a lack of capacity can lead to missed opportunities. There is no net under this tightrope. You have to get the balance right.
How much server capacity do you have right now? Are you actively monitoring capacity, or are you just setting alarms to let you know when it is almost gone? And as your capacity is consumed, do you know where it is going? Five different project planners may think they have sufficient capacity available, but if they were all looking at the same pool of available resources, you could be in serious trouble if even two of those five projects move forward.
Virtualization exposes previously masked deficiencies as it decreases provisioning times and speeds up server deployments. For example, before you virtualized, you may have provisioned hardware and scheduled firewall rules concurrently. If provisioning hardware took, say, three weeks, it didn't matter that it took two weeks to schedule firewall rules. But as soon as virtualization shortened the hardware provisioning time to three days, the firewall scheduling suddenly became the roadblock. This is just one of the factors that can work to upset the capacity planning balancing act.
Organizations can usually consume resources pretty quickly, but replenishing those resources can involve bidding, quotes and a number of signatures before orders are even placed -- and then there is shipping, receiving, racking, cabling, etc. You cannot do capacity planning for tomorrow, because by the time you get your additional resources, you'll already need even more. You need to be looking at least two months out.
You may also need to re-evaluate and consider streamlining your procurement process to address capacity planning needs. If you are in a position to have your vendors deliver excess resources that you will not pay for until powering them on, that could be a good option to help you respond to demand more quickly.
Capacity planning is a critical task for IT shops. If you are implementing virtualization or managing a cloud computing infrastructure, you have placed your capacity planning and management under a microscope. The success or failure of your environment is directly tied to your ability to manage capacity.
About the expert
Mark Vaughn (MBA, VCP, BEA-CA) serves as an enterprise architect for a multinational corporation. Vaughn has more than 14 years of experience in IT as a Unix administrator, developer, Web hosting administrator, IT manager and enterprise architect. For several years, he has focused on using the benefits of virtualization to consolidate data centers, reduce total cost of ownership, and implement policies for high availability and disaster recovery. Vaughn is a recipient of the 2009 vExpert award and has delivered several presentations at VMworld and BEAWorld conferences in the U.S. and Europe. Read his blog at http://blog.mvaughn.us/.