Chapter 2. Designing VMware ESXi Host, Cluster, and vCenter

The core elements that are responsible for the success of virtualizing our datacenter start with accurate design of ESXi and vCenter. VMware ESXi is a host OS, installed on bare metal, which is a driving factor for virtual datacenters and the cloud. VMware's ESXi hypervisors have changed a lot over the years, and the foundation of the enterprise contribution has undergone a structured transition phase.

There are a plenty of implementation options for ESXi deployment that tell us about product growth and maturity. We'll compare the choices, looking at the returns from each implementation to decide which one will be more suitable for different environments. An enterprise can now rollout ESXi in a straightforward manner and manage it constantly with policy management. In this chapter, we'll discuss the essential configurations that are required in VMware vSphere design and how to effectively design the management...

Design essentials for ESXi

VMware ESXi is the primary component in the VMware integrated environment. ESXi (short for Elasticity Sky X), which was formerly known as ESX and GSX, is a world-class, Type 1 hypervisor developed by VMware for implementing virtual datacenters. As a Type 1 hypervisor, ESXi is not an application—it is an OS that integrates vital OS components such as a kernel.

ESXi 5.5.0 Update 2 is the latest version and has updated drivers. It is available for public download and the following table shows the release history:

Date of Release	Name of the Release	Version	Build
December 2, 2014	ESXi550-201412001	ESXi 5.5 Express Patch 5	2302651
October 15, 2014	ESXi550-201410001	ESXi 5.5 Patch 3	2143827
September 9, 2014	VMware ESXi 5.5 Update 2	ESXi 5.5 Update 2	2068190
July 1, 2014	ESXi550-201407001	ESXi 5.5 Patch 2	1892794
June 10, 2014	ESXi550-201406001	ESXi 5.5 Express Patch 4	1881737
April 19, 2014	ESXi550-201404020	ESXi 5.5 Express Patch 3...

Designing ESXi

The VMware ESXi design comprises the fundamental OS and processes that run on top of ESXi, and it is called VMkernel. VMkernel runs all processes on ESXi, including ESXi agents, management software, as well as virtual machines. ESXi gains control over hardware devices on the physical servers and manages resources for the virtual machines. The main processes that route on top of the ESXi VMkernel are as follows:

Direct Console User Interface (DCUI)
Virtual Machine Monitor (VMM)
Several agents used to enable high-level VMware infrastructure management from remote applications
Common Information Model (CIM)

VMkernel is a POSIX-like OS developed by VMware and provides functionalities similar to other OS', such as control, process creation, process threads, signals, and filesystems. ESXi is designed precisely to support multiple VMs and provide core functionalities such as resource scheduling, I/O stacks, device drivers, and so on.

VMware ESXi was restructured to permit VMware...

Design configurations for ESXi

In this section, you will see the key configurations that are required while designing VMware ESXi. All of the VMware ESXi hosts should be identical in terms of hardware specifications and should be built and configured reliably, to diminish the amount of operational effort involved with patch management, and to provide a building block solution. The following table illustrates the maximum configuration required while designing ESXi on your infrastructure:

Item	Designed to support	Max supported
Host CPU maximums	Logical CPUs per ESXi host	320
Host CPU maximums	NUMA Nodes per ESXi host	16
Virtual machine maximums	Virtual machines per ESXi host	512
	Virtual CPUs per ESXi host	4096
	Virtual CPUs per core	321
Fault Tolerance maximums	Virtual disks per ESXi host	16
	Virtual CPUs per VM	1
	RAM per FT VM	64 GB
	Virtual machines per ESXi host	4
Memory	RAM per ESXi host	4 TB
Memory	Number of swap files per VM	1
Virtual Disks	Virtual Disks per ESXi host	2048
ISCSI...

Key design considerations for ESXi

In this section, the following are the most important considerations for your VMware ESXi design:

Consider using VMware Capacity Planner to investigate the performance and usage of prevailing servers; this will help you to identity the requirements for planning.
Consider eliminating inconsistency and achieving a controllable and manageable infrastructure by homogenizing the physical alignment of the ESXi hosts.
Never design ESXi without a remote management console such as DRAC and ILO.
Ensure that syslog is properly set up for your virtual infrastructure and log files are offloaded to non-virtual infrastructures.
Consult your server vendor on proper memory DIMM size, placement, and type to get optimal performance. While other configurations may work, they can greatly impact memory performance.
Ensure you choose the right hardware for the ESXi host, while aligning the functional requirements with a workload that has a baseline and performance that has a benchmark...

Designing an ESXi scenario

Let's apply what we have learnt so far in designing ESXi 5.5 in the following scenario. Let's start with hardware merchant for our design is Dell. In this scenario, the Dell PowerEdge R715 server has been chosen as the hardware for designing and implementing VMware ESXi 5.5. The configuration and assembly process for each system should be homogeneous, with all components installed identically for all VMware ESXi 5.5 hosts. Homogenize not only the model but also the physical configuration of the VMware ESXi 5.5 hosts, to provide a simple and supportable infrastructure by eliminating unevenness. The specifications and configuration for this hardware platform are detailed in the following table:

Attributes	Modules
Vendor	Dell
Model	PowerEdge R715
Number of CPU sockets	4
Number of CPU cores	16
Processor speed	2.3 GHz
Number of network adaptor ports	8
Network adaptor vendor(s)	Broadcom/Intel
Network adaptor model(s)	2x Broadcom 5709C dual...

Design essentials for ESXi

VMware ESXi is the primary component in the VMware integrated environment. ESXi (short for Elasticity Sky X), which was formerly known as ESX and GSX, is a world-class, Type 1 hypervisor developed by VMware for implementing virtual datacenters. As a Type 1 hypervisor, ESXi is not an application—it is an OS that integrates vital OS components such as a kernel.

ESXi 5.5.0 Update 2 is the latest version and has updated drivers. It is available for public download and the following table shows the release history:

Date of Release	Name of the Release	Version	Build
December 2, 2014	ESXi550-201412001	ESXi 5.5 Express Patch 5	2302651
October 15, 2014	ESXi550-201410001	ESXi 5.5 Patch 3	2143827
September 9, 2014	VMware ESXi 5.5 Update 2	ESXi 5.5 Update 2	2068190
July 1, 2014	ESXi550-201407001	ESXi 5.5 Patch 2	1892794
June 10, 2014	ESXi550-201406001	ESXi 5.5 Express Patch 4	1881737
April 19, 2014	ESXi550-201404020	ESXi 5.5 Express Patch 3	1746974...

Designing ESXi

The VMware ESXi design comprises the fundamental OS and processes that run on top of ESXi, and it is called VMkernel. VMkernel runs all processes on ESXi, including ESXi agents, management software, as well as virtual machines. ESXi gains control over hardware devices on the physical servers and manages resources for the virtual machines. The main processes that route on top of the ESXi VMkernel are as follows:

Direct Console User Interface (DCUI)
Virtual Machine Monitor (VMM)
Several agents used to enable high-level VMware infrastructure management from remote applications
Common Information Model (CIM)

VMkernel is a POSIX-like OS developed by VMware and provides functionalities similar to other OS', such as control, process creation, process threads, signals, and filesystems. ESXi is designed precisely to support multiple VMs and provide core functionalities such as resource scheduling, I/O stacks, device drivers, and so on.

VMware ESXi was restructured to permit VMware consumers...

Design configurations for ESXi

In this section, you will see the key configurations that are required while designing VMware ESXi. All of the VMware ESXi hosts should be identical in terms of hardware specifications and should be built and configured reliably, to diminish the amount of operational effort involved with patch management, and to provide a building block solution. The following table illustrates the maximum configuration required while designing ESXi on your infrastructure:

Item	Designed to support	Max supported
Host CPU maximums	Logical CPUs per ESXi host	320
Host CPU maximums	NUMA Nodes per ESXi host	16
Virtual machine maximums	Virtual machines per ESXi host	512
	Virtual CPUs per ESXi host	4096
	Virtual CPUs per core	321
Fault Tolerance maximums	Virtual disks per ESXi host	16
	Virtual CPUs per VM	1
	RAM per FT VM	64 GB
	Virtual machines per ESXi host	4
Memory	RAM per ESXi host	4 TB
Memory	Number of swap files per VM	1
Virtual Disks	Virtual Disks per ESXi host	2048
ISCSI...

Key design considerations for ESXi

In this section, the following are the most important considerations for your VMware ESXi design:

Consider using VMware Capacity Planner to investigate the performance and usage of prevailing servers; this will help you to identity the requirements for planning.
Consider eliminating inconsistency and achieving a controllable and manageable infrastructure by homogenizing the physical alignment of the ESXi hosts.
Never design ESXi without a remote management console such as DRAC and ILO.
Ensure that syslog is properly set up for your virtual infrastructure and log files are offloaded to non-virtual infrastructures.
Consult your server vendor on proper memory DIMM size, placement, and type to get optimal performance. While other configurations may work, they can greatly impact memory performance.
Ensure you choose the right hardware for the ESXi host, while aligning the functional requirements with a workload that has a baseline and performance that has a benchmark...

Designing an ESXi scenario

Let's apply what we have learnt so far in designing ESXi 5.5 in the following scenario. Let's start with hardware merchant for our design is Dell. In this scenario, the Dell PowerEdge R715 server has been chosen as the hardware for designing and implementing VMware ESXi 5.5. The configuration and assembly process for each system should be homogeneous, with all components installed identically for all VMware ESXi 5.5 hosts. Homogenize not only the model but also the physical configuration of the VMware ESXi 5.5 hosts, to provide a simple and supportable infrastructure by eliminating unevenness. The specifications and configuration for this hardware platform are detailed in the following table:

Attributes	Modules
Vendor	Dell
Model	PowerEdge R715
Number of CPU sockets	4
Number of CPU cores	16
Processor speed	2.3 GHz
Number of network adaptor ports	8
Network adaptor vendor(s)	Broadcom/Intel
Network adaptor model(s)	2x Broadcom 5709C dual-port onboard...

Design essentials for upgrading ESXi

ESXi hosts can be upgraded from previous version or from ESXi 4.x in several ways. ESXi Installable 4.x hosts can be upgraded in one of three ways:

An interactive upgrade via an ESXi Installable image
A scripted upgrade, or using VUM. ESXi 5.0 hosts can be upgraded to 5.1
The esxcli command-line tool

Note

If we have implemented Auto Deploy, we can directly apply a new image and reboot.

While upgrading VMware ESXi hosts from a previous version of ESXi 4.x to the latest version of 5.x using any of the three supported approaches, 50 MB must be accessible on the local VMFS volume. This space is required to store the ESXi server's configuration data in temp mode.

The following table illustrates approaches for upgrading ESXi to the latest version: