Adapted from the Virtual Server 2005 R2 Resource Kit - Chapters 12-14
Many companies are looking at server consolidation as a way to reduce their IT infrastructure costs. Making the move requires project justification and projected costs and cost savings before they will be given the budget for the project.
When we wrote the Virtual Server 2005 R2 Resource Kit, we wanted to not only tell you how to deploy, use, manage, and operate the product, but how to assemble a project from envisioning to pilot. This information is adapted from those chapters of the book.
The following is a summary of the first steps of a project that lets you assemble the project justification.
1) Envision the project2) Discover your infrastructure3) Analyze the data4) Determine project costs and cost savings5) Write a great project proposal
Envisioning the project
Envisioning is all about getting the project team to agree on the project vision, problem statements, goals, scope, issues, risks, and expected end state. This is extremely important so that you can focus on only what is within the scope of the project and so you can accurately explain to the executive sponsor what the project will accomplish.
Discovering your infrastructure
Before you can determine what can be virtualized you need to assemble the data to analyze. This should involve collecting hardware, software, and performance information on every server that is a potential candidate. You also want to assemble the space and power rating information for each server
Hardware inventory should include the configuration information for the processor (speed, #procs, #cores, make, model, stepping), memory (installed), network (# NICs, speed, MAC, IP, make, model), and disk systems (#disks, size, total space, space available).
Software inventory should include the installed applications, version, and update information.
Performance data should collect information for processors, memory, network, and disk. You typically want to collect utilization (max, min, avg) and usage information, and collect it for each component if there are multiple. You want to collect the data over a period of 30 days so that you see the workload signature of the server over an entire business cycle.
Space information is typically how many rack units a server requires. Power rating is combined rating of all the power supplies in the server.
[You will find scripts and reference to tools to assist in the data collection in the Virtual Server 2005 R2 Resource Kit DVD)
Analyzing the data
Once you have the data, you need to determine the following:
1) Determine any exclusions you want to set or have to set due to the limitations of your virtualization solution (for example servers with 64-bit OS for Virtual Server guests)2) Set your usage or performance criteria for a virtualization candidate (memory - MB, processor - MHz, Disk - GB, NIC - Mb/s)3) Remove the servers that meet the exclusions4) Evaluate each machine against the criteria candidate criteria.5) Group the servers on how they will be consolidated6) Determine the host configurations you will use and set thresholds7) Combine the workloads of each group of servers so that you get as close to the thresholds you set without exceeding them. Count the number of required hosts.
So now you should know the number of hosts required for each location.
[You will find sample spreadsheets on the Virtual Server 2005 R2 Resource Kit DVD that will make this a simpler process)
Determine project cost savings
1) Evaluate the hardware from all the virtualization candidates for possible reuse as hosts2) Combine all the space and power requirements together to determine the amount of space, power, and cooling that can be saved from the project.3) Determine the capital costs savings from eliminating the physical servers4) Determine or approximate the cost savings for supporting hardware like KVMs, Monitors, network switches, etc.
Determine the Project Costs
There will be costs in the implementation. You will be deploying new servers, new software, and modifying processes.
1) Determine the cost of the hardware for the Virtual Server hosts (offset by the reusable servers). Do not forget any supporting hardware like disk cabinets, switches, etc..)2) Determine the cost of Windows 2003 Data Center Edition (you want to use this one so you can freely move virtual machines around), you will need a single license per host.3) Determine the cost of the virtualization software a) Virtual Server - free b) SCVMM, SCOM, SCDPM - E-SML license4) Determine the cost of any consulting services5) Determine the deployment cost6) Determine the training cost
Writing the Proposal
Now you have all the information about the virtualization candidates, number of required hosts, cost savings, and project costs, now is the time to assemble the proposal to management. The proposal should include a summary of the vision and scope, the risks, the assessment findings, the project costs, then the project savings.
Hopefully the project savings outweigh the project costs by a hefty factor to make the discussion quick and painless.
For more detailed discussion on these topics, refer to the Virtual Server 2005 R2 Resource Kit from Microsoft Press.