VMware vSphere Design

Forbes Guthrie, Scott Lowe, Kendrick Coleman

• Publisher: Sybex
• Year: 2013
• ISBN:
  9781118493946
• Edition: 2
• Topic: Informatica
• Subtopic: Virtualizzazione

Achieve the performance, scalability, and ROI your business needs

What can you do at the start of a virtualization deployment to make things run more smoothly? If you plan, deploy, maintain, and optimize vSphere solutions in your company, this unique book provides keen insight and solutions. From hardware selection, network layout, and security considerations to storage and hypervisors, this book explains the design decisions you'll face and how to make the right choices.

Written by two virtualization experts and packed with real-world strategies and examples, VMware vSphere Design, Second Edition will help you design smart design decisions.

• Shows IT administrators how plan, deploy, maintain, and optimize vSphere virtualization solutions
• Explains the design decisions typically encountered at every step in the process and how to make the right choices
• Covers server hardware selection, network topology, security, storage, virtual machine design, and more
• Topics include ESXi hypervisors deployment, vSwitches versus dvSwitches, and FC, FCoE, iSCSI, or NFS storage

Find out the "why" behind virtualization design decisions and make better choices, with VMware vSphere Design, Second Edition, which has been fully updated for vSphere 5.x.

Chapter 1
An Introduction to Designing VMware Environments

Designing VMware vSphere environments can be a complex topic, one that means many different things to many different people. In this chapter, we'll provide an introduction to designing VMware vSphere implementations. This introduction will give a preview of some of the more detailed discussions that take place in later chapters and will provide a framework for how the other chapters fit into the overall process.

This chapter will cover the following topics:

• The importance of functional requirements in VMware vSphere design
• The what, who, and how questions involved in VMware vSphere design and why they're important
• An overview of the VMware vSphere design process

What Is Design?

When we talk about “designing your VMware vSphere environment,” what exactly does that mean? In the context of VMware vSphere, what is design? What does design entail? These are excellent questions — questions that we intend to answer in this chapter and the coming chapters throughout this book.

In our definition, design is the process of determining the way in which the different elements that make up a VMware vSphere environment should be assembled and configured to create a virtual infrastructure that is strong yet flexible. Design also includes the process of determining how this virtual infrastructure will integrate with existing infrastructure as well as how the virtual infrastructure will be operated after the implementation is complete.

That's a reasonable definition; but for someone who is new to VMware vSphere design, does this really describe what design is? Does it help you understand the nature of design, or what makes up a design?

In looking at a VMware vSphere design, we can say that it has three key facets: the technical or structural facet, the organizational facet, and the operational facet. Figure 1.1 shows how these three facets are all part of the larger entity that we refer to as design.

These three facets serve to organize the design in a way that is logical to us, grouping together information, decisions, criteria, constraints, and standards. We'll explore these facets in more detail later in this chapter in the section titled “The Facets of vSphere Design.”

Figure 1.1 The different parts of VMware vSphere design are merely facets of a larger entity.

When defined or described this way, VMware vSphere design seems simple. But as you'll see in this book — or perhaps as you've already seen, depending on your experience — it can be complex. Even in the most complex of designs, however, a single unifying element brings the different facets together. What is this single unifying element, as illustrated in Figure 1.2? It's the functional requirements of the design.

Figure 1.2 The functional requirements unify the different facets of the design.

Functional requirements are incredibly important. In fact, we can't stress enough the key role that functional requirements play in VMware vSphere design (or any IT design task, for that matter). Functional requirements are important because they answer the question “What things should this design do?”

It's important to remember that companies implement VMware vSphere for a reason, not just for the sake of having vSphere installed. As much as VMware would love for that to be the case, it's not. In every instance, there's a driving factor, a force, a purpose behind the implementation. There's a reason the company or organization is implementing VMware vSphere. That reason, naturally, varies from customer to customer and organization to organization.

Here are some example reasons taken from our own experience in the virtualization industry:

1. Consolidation The company or organization has too many physical servers and needs to reduce that number. The need to reduce the number of physical servers can be driven by any number of reasons, including a need to reduce data-center space usage, a need to cut power and cooling costs, or an attempt to reduce hardware refresh costs.
2. New Application Rollout The company or organization is deploying a new application or a new service in its data center, and it has chosen to use virtualization as the vehicle to accomplish that deployment. This may be a deployment of a new version of an application; for example, a company currently using Exchange 2007 may decide to roll out Exchange 2010 in a virtualized environment on VMware vSphere. As another example, a company deploying SAP may choose to do so on VMware vSphere. The reasons for choosing to deploy on a virtualized environment are too numerous to list here, but they can include increased utilization, simplified deployment, and better support for a disaster recovery/business continuity (DR/BC) solution.
3. Disaster Recovery/Business Continuity (DR/BC) The company or organization is in the midst of developing or enhancing its DR/BC solution and has chosen to use virtualization as a key component of that solution. Perhaps the company is using array-based replication and wishes to use VMware vSphere and VMware Site Recovery Manager (SRM) to provide a more automated DR/BC solution. The choice to use virtualization as a component of a DR/BC solution is almost always a financial one; the company or organization wishes to reduce the amount of downtime (thus minimizing losses due to downtime) or reduce the cost of implementing the solution.
4. Virtual Desktop Infrastructure The company or organization wishes to deploy a virtual desktop infrastructure (VDI) in order to gain desktop mobility, a better remote-access solution, increased security, or reduced desktop-management costs. Whatever the motivation, the reason for the VMware vSphere environment is to support that VDI deployment.

As you can see, the reasons for adopting virtualization are as varied as the companies and organizations. There is no one reason a company will adopt virtualization, but there will be a reason. There are often multiple reasons. These reasons become the basis for the functional requirements of the design. The reasons are the things the design must do. Functional requirements formalize the reasons why the company or organization is adopting VMware vSphere and turn them into actionable items that you'll use to drive all the other decisions in the design.

Think about some of the examples we just provided. Does the organization plan to virtualize a new rollout of Microsoft Exchange Server 2010? If so, then the VMware vSphere design had better accommodate that functional requirement. The design must specifically accommodate Microsoft Exchange Server 2010 and its configuration needs, supportability requirements, and resource constraints. If you fail to properly account for the fact that Microsoft Exchange Server 2010 will run in this virtualized environment, then you've failed to consider one of the design's functional requirements — and, in all likelihood, the implementation will be a failure. The design will fail to do the thing the company needs it to do: run Microsoft Exchange Server 2010.

With this in mind, you can look back at Figure 1.2 and better understand how the functional requirements both surround and unify the facets of VMware vSphere design. Continuing in our example of an organization that is deploying Exchange Server 2010 in a virtualized environment, the functional requirements that derive from that reason affect a number of different areas:

• The server hardware selected needs to be capable of running the virtual machines configured with enough resources to run Microsoft Exchange Server 2010.
• The virtual machines that run Exchange will, most likely, need to be configured with more RAM, more virtual CPUs (vCPUs), and more available disk space.
• The configuration of Exchange Server 2010 will affect cluster configurations like the use of vSphere High Availabi...