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:

After Version 4.1, VMware released another version named ESXi. ESXi replaces Service Console, which is nothing but an elementary OS, with a more tightly integrated OS.

The decision to Service Console fundamentally changed what was conceivable with VMware's hypervisor. VMware ESXi demands a much smaller server footprint, so the hypervisor consumes fewer host resources to perform essentially the same functions that were performed by ESX—this is a great consolidation. ESXi also offers reduced disk utilization—whether it is OS or application, data that is consumed from local disk, or booting from a SAN disk.

The best advantage of ESXi is reduced base code, which is good in terms of security. Previous versions of ESX were shipped and downloadable with a file size of 2 GB, whereas the present ESXi version is 125 MB. It's easy to see that less code implies fewer security requirements as there is a smaller attack vector. The ESX Service Console provides additional software security, which ESXi avoids.

ESXi patches are released less frequently and are easy to apply across virtual datacenters; this massively reduces the administrative burden from a management standpoint. This is another great advantage of ESXi.