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vCenter Server is a critical application for managing your virtual infrastructure. Its implementation should be carefully designed and executed to ensure availability and data protection. When discussing the deployment of vCenter Server and its components, the following questions are among the most common questions to ask:

• How much hardware do I need to power vCenter Server?

• Which database server should I use with vCenter Server?

• How do I prepare vCenter Server for disaster recovery?

• Should I run vCenter Server in a VM and, if so, so I need a separate management cluster?

Many of the answers to these questions are dependent on each other, but we have to start somewhere, so let’s start with the first topic: figuring out how much hardware you need for vCenter Server.

Sizing Hardware for vCenter Server

The amount of hardware that vCenter Server requires is directly related to the number of hosts and VMs it will be managing. This planning and design consideration applies only to the Windows Server–based version of vCenter Server; because it is a prepackaged virtual appliance, the virtual hardware of the vCenter Server virtual appliance is predefined and established before it is deployed.

As a starting point, the minimum hardware requirements for the Windows Server–based version of vCenter Server are as follows:

• Two 64-bit CPUs or a single dual-core 64-bit CPU

• 8 GB of RAM or more

• 17 GB of free disk space

• A network adapter (Gigabit Ethernet strongly recommended)

• A supported version of Windows (Windows Server 2008 R2, Windows Server 2012, or Windows Server 2012 R2); vCenter Server 6 requires a 64-bit version of Windows

Keep in mind these are minimum system requirements. Large enterprise environments with many ESXi hosts and VMs must scale the vCenter Server system accordingly.

Sizing Disks on vCenter Server

Disk storage allocation is of minimal concern when planning a vCenter Server installation because the data is generally stored in a SQL or Oracle database on a remote server.

The minimum requirements for the Windows Server–based edition of vCenter Server do not account for running a database server, which vCenter Server requires. Although vCenter Server is the application that manages your ESXi hosts and VMs, vCenter Server uses a database for storing all of its configuration, permissions, statistics, and other data. Figure 3.5 shows the relationship between vCenter Server and the separate database server.

Figure 3.5 vCenter Server acts as a proxy for managing ESXi hosts, but all of the data for vCenter Server is stored in a database.

When answering the question of how much hardware vCenter Server requires, you have to address the computer running vCenter Server and the one running the components it depends on, which include the following components:

• Database server

• Platform Services Controller

• Any other services you wish to co-locate

Although you can run vCenter Server and its dependencies on the same machine, it’s usually not recommended because it creates a single point of failure for key aspects of your virtual infrastructure. However, sometimes you don’t have a choice, especially in smaller environments where capacity is at a premium. Keep in mind that VMware recommends 8 GB of RAM if vCenter Server is installed with an embedded Platform Services Controller but only for environments with up to 20 ESXi hosts or 400 VMs. This would be the case if you use the Embedded option when installing vCenter Server.

Throughout this chapter, we’ll use the term separate database server to refer to a database server application that is separately installed and managed. Although it might reside on the same computer, it is still considered a separate database server because it is managed independently of vCenter Server. You’ll also see the term backend database, which refers to the actual database that vCenter Server uses on the separate database server.

VMware suggests vCenter hardware requirements depending on the size of the environment that vCenter will be managing. Table 3.1 shows these recommendations.

Table 3.1 vCenter sizing

CPU Cores

Most modern physical servers ship with at least quad-core CPUs. As you can see based on VMware’s recommendations, vCenter Server will leverage multiple CPU cores when necessary.

Should you choose to run the separate database server on the same physical computer as vCenter Server, you’ll need to consult the documentation for your chosen database server. Without a doubt, the database server requires additional CPU capacity, RAM, and disk storage just like other co-located services, so you will need to plan accordingly. That brings us to the next topic: choosing which database server to use.