What is ESXi, vCenter and vShpere Client

ESXi Server

Its a type 1 Hypervisor also know as Bare metal hypervisor developed by vmware.

ESXi directly installs in your physical server which enables you to create multiple virtual machines, you can use ESXi with either the free vShpere hypervisor without some additional features or the paid edition of vSphere hypervisor.

Difference between ESX and ESXi

After version 4.1 vmware renamed ESX to ESXi  and replace service console with DCUI (direct control user interface) some of the major benefits are follows:

vCenter Server

vCenter Server previously know as vmware virtual center some of the benefits are as follows

• Its used for centralized control and visibility of multiple ESX/ESXi hosts.
• Contains centralized license management.
•  Provides most advance features of vmware vshpere like vmotion etc.

Pre-requisites for installing vCenter version 6

Software requirement: Wnidows 2008 R2 64 bit or later and should not be a domain controller.

Hardware requirement: Dual-Core 64 bit processor with minimum 8GB of RAM. 

vShpere Client

vShpere client is used to access ESXi host or vCenter server the diagram below gives descriptive idea of vsphere suits.

Graphics thanks to vmware

This covers the working of VShpere suit as we can observe there is one physical server installed with ESXi server running virtual machines and sharing the resources like CPU and memory from host server (physical).

vCenter itself installed in vm in windows server, we can also use VCSA (vCenter Server appliance) linux based vCenter pre-installed with vCenter or we can have dedicated physical server. Best practise is to have it on vm if there any issues in physical server or its require down time maintenance in some activity so we can migrate the vCenter to another ESXi server so its doesn't impact on daily operation. To access this vcenter we require a client machine can be a laptop or desktop with vSphere client installed in it, from vShpere client we can access vcenter server and ESXi server by simply providing a IP address and login credentials. In big environment with multiple ESXi hosts an dozens of vm its highly recommended to have at-least one vCenter server its makes easier to manage ESXi hosts and vms, templates no need to login on each ESXi server and alos its comes with additional features like vmotion, DVSwitch, etc which makes the daily activity of vmware admin easier.