Understanding ESXi and ESX Architectures

Difference between ESX and ESXi

ESX architechture

1.The VMkernal is the virtualisation kernal is added to a console operating system, also called as COS .VMware agents run in Console OS
2.Management Agents are deployed in the COS.
(eg:3rd party software , logging etc)
3. Serveral Administrators logon to COS to run config and diagnostic commands and scripts


ESXi Architechture

1. The console operating system has been removed in this architecture and the VMkernal has the ability to run the Vmware agents directly on them.
2.Infrastructure services are provided natively through modules included with the vmkernel
3. Authorized 3rd party modules , such as hardware drivers and hardware monitoring components, can run directly on vmkernal
4. Only modules that have been digitally signed by VMware are allowed on the system, creating a tightly locked-down architecture

Source : http://www.vmware.com/products/vsphere/esxi-and-esx/compare.html#understand

Capability	ESX 4.1	ESXi 4.1	ESXi 5.0
Service Console	Present	Removed	Removed
Admin/config CLIs	COS + vCLI	PowerCLI + vCLI	PowerCLI + vCLI (enhanced)
Advanced Troubleshooting	COS	Tech Support Mode	ESXi Shell
Scripted Installation	Supported	Supported	Supported
Boot from SAN	Supported	Supported	Supported
SNMP	Supported	Supported (limited)	Supported
Active Directory	Integrated	Integrated	Integrated
HW Monitoring	3rd party agents in COS	CIM providers	CIM providers
Serial Port Connectivity	Supported	Not Supported	Not Supported
Jumbo Frames	Supported	Supported	Supported
Rapid deployment and central management of hosts via Auto Deploy	Not Supported	Not Supported	Supported
Custom image creation and management	Not Supported	Not Supported	Supported
Secure syslog	Not Supported	Not Supported	Supported
Management interface firewall	Supported	Not Supported	Supported