Choosing the hardware platform

An important decision to take when planning an ESXi deployment is the choice of the hardware platform of the server. ESXi doesn't support all the hardware available on the market (storage controllers, NICs, and so on) and has some restrictions that can prevent successful installation of the hypervisor.

Only tested and supported hardware ensures that your ESXi can be installed without any problem and can operate as expected. Before purchasing the hardware for your server, it is strongly recommended you verify whether the chosen hardware platform is supported by ESXi.

To check for hardware compatibility, you can refer to the VMware Compatibility Guide available at the URL https://www.vmware.com/resources/compatibility/. The list of tested hardware is large and you can find the supported hardware from the main manufacturers, such as HP, Dell, IBM, and Cisco.

You can also use some white-box solutions but keep in mind that using a hardware platform included in the HCL ensures not only a successful ESXi deployment but also VMware technical support. When new hardware is released and certified for compatibility, the list of supported vendors is updated accordingly:

Search the Compatibility Guide available from the VMware website to check hardware for compatibility

A good practice could be to test the system for 72 hours to verify and check for possible hardware errors.

Choosing the right server for your installation is not an easy task, especially if your environment grows quickly and the business requirements change frequently. Capability, scalability, availability, and support are the elements of the server you need to evaluate carefully to be sure the final choice fits in the available budget without affecting the global design.

If you need to provide a large amount of resources to your infrastructure, a big server isn't necessarily the best choice.

In some scenarios, it is better to have more, smaller servers in a cluster to provide the required resources than a few big servers. The obvious question could be—why are smaller servers a better choice? Servers with more powerful CPUs and lots of RAM installed necessarily raise the costs for purchase and for support.

In the event that one ESXi fails, it's one thing to replace a server with dual CPU sockets and 128 GB of RAM; it's a different story if the server to be replaced has 6 or more CPU sockets and 512 GB of RAM. In terms of costs, the difference is enormous and often it's hard to justify the investment to the management. The challenge is to find a server that provides the amount of resources that meets the requirements but at the same time supports enough expansion (scalability) if the demand for resources grows.

Another factor you should consider is the expected performance of the server. The default hardware BIOS settings of the chosen hardware do not always ensure the best performance. To optimize performance, you should check some of the following settings on your server's BIOS settings:

• Hyperthreading should be enabled for processors that support it
• Enable turbo boost if your processors support it
• In NUMA-capable systems, disabling node interleaving (leaving NUMA enabled) will give you the best performance
• Hardware-assisted virtualization features, such as VT-x, AMD-V, EPT, RVI, and so on should be enabled
• vSphere 6.5 includes features that perform significantly better, incur significantly lower CPU load, or both, on hardware that supports Intel's Advanced Encryption Standard New Instruction Set (AES-NI)
• Consider whether you should disable any devices you won't be using from the BIOS
• For power management, you can choose to enable max performance or leave the control at ESXi with OS Controlled Mode