Optimizing Virtual Machine Placement

The process for optimizing virtual machine placement includes the following stages:

First, you need to collect historical performance information for the virtual machine workload. To optimize virtual machine placement, you start by collecting historical performance information about the existing physical computers or virtual machines. SCOM 2007 can record and analyze performance information about physical computers and virtual machines for both consolidation and virtualization.
Then, you need to check the minimum resource requirements for the configuration of the virtual machine. For each planned virtual machine, you check the minimum resource requirements, such as processor, memory, hard disk space, and network bandwidth. To calculate the host memory usage, you need to add 32 MB of memory overhead for each virtual machine.
Now, you estimate the number of simultaneous virtual machines that the host computer can support. While estimating, you must pay attention to factors such as total memory (allow 512 MB for the parent partition), number of virtual processors (do you plan to assign a processor core to an individual virtual machine in dual-core or quad-core computers?), virtual hard disk storage (expected file growth), and network connectivity (placing computers with large mutual data transfer requirements on the same host computer).
You then select resource maximization or load balancing. To optimize for resource maximization requirements, you place virtual machines on a host computer until the resources of the host computer are fully assigned. You need to remember that the queuing theory prevents some resource areas, such as processor activity, from reaching maximum usage. To optimize for load balancing, you must assign virtual machines to two or more host computers so that each host computer experiences approximately equal resource usage.
Then, you convert all physical computers to virtual machines.
Next, you need to deploy the virtual machines on the host computer and start the images.
Finally, you need to monitor resource usage and check that the measured figures match predictions. As each virtual machine starts, you need to monitor static resource usage, such as memory usage. As you switch clients over to the virtual images, you also need to monitor active resource usage, such as processor and network usage. If necessary, you can continue monitoring and adjusting virtual machine placements.