Engaging in a server consolidation project is no easy task. It's not easy no matter how much research you've put into it. Converting physical systems to virtual systems is the least of your worries--that's the easy part. The hard part? Getting it right--the consolidation part, that is. You can't rush consolidation. It takes time and a lot of it. You have to gather performance data, analyze that data, make recommendations on which workloads can be consolidated. In sum, it's a painful process. But, it doesn't have to be as painful, if you virtualize first.
Yes, you read that correctly. Virtualize first and then consolidate.
It's simple, really. If you move your systems to virtual ones first, you've taken the first critical step in the process and simplified your infrastructure. Virtual machines are easier to deal with than physical ones. Plus, by taking the virtualization step first, you've already consolidated by a considerable amount. Even if your physical to virtual ratio is 10 physicals to 1 virtual host, that's a significant hardware reduction.
Next, you need to continue to monitor performance for all of your virtual systems before you take the next step toward further consolidation. Remember that beyond hardware reduction, a major reason for consolidation is to increase hardware utilization. You don't want idle systems wasting hardware.
It's likely that a few weeks of monitoring those new virtual systems will yield further reductions in server footprint. Pay particular attention to performance spikes, sustained utilization, idle time and service delivery. It's perfectly acceptable for a system to run at very high utilization for short periods of time. It is not acceptable for high utilization to cause service outages.
Performance must be measured on the server side and the client side alike to appropriately assess utilization and its effect on user experience. You might observe a handful of ten minute bursts of activity on the server side and arrive at the incorrect conclusion that everything is OK. From your point-of-view, everything is OK but from the user's point-of-view, those spikes represent frustrating session timeouts and eventual loss of income, loss of customer loyalty and loss of quiet phone lines in customer service.
Server consolidation efforts come with sacrifices--sacrifices of time and energy that often cannot be billed or recaptured in any way. This is frustrating for you, your management and your clients. Taking the effort one step at a time, with virtualization being the first step, you'll save yourself a lot of time up front and possibly have to go no further with your consolidation tasks.
Remember that a one-to-one physical to virtual conversion still provides enough consolidation success to impress any bean counter. If you can take it further, after appropriate assessment, your success will be even sweeter. You can now ask for that raise.
Have you performed server consolidations via virtualization that have yielded so much success in the P2V process that you've had to go no further?