VMware vSphere virtualizes and aggregates the underlying physical hardware resources across multiple systems and provides pools of virtual resources to the datacenter.

Virtualization is a process that breaks the hard connection between the physical hardware and the operating system and applications running on it. After being virtualized in a vSphere virtual machine, the operating system and applications are no longer constrained by the limits imposed by residing on a single physical machine. Virtual equivalents of physical elements such as switches and storage operate within a virtual infrastructure that can span the enterprise.

The x86 computer hardware is designed to run a single operating system and a single application, leaving most machines underused. Even with many applications installed, most machines are underused. At the most basic level, virtualizing lets you run multiple virtual machines on a single physical machine, with each virtual machine sharing the resources of that one physical computer across multiple environments. Different virtual machines can run different operating systems and multiple applications, in isolation, side-by-side on the same physical machine.

Virtualizing the Computer and Adding Virtual Machines
The diagram shows three systems: an unvirtualized system, a system that has had its OS and applications moved to a virtual machine, and one that has additional virtual machines added.

In addition to virtualizing a single physical computer, you can build an entire virtual infrastructure with VMware vSphere, scaling across thousands of interconnected physical computers and storage devices. Using virtualization, you can dynamically move resources and processing and allocate hardware resources. You do not need to assign servers, storage, or network bandwidth permanently to each application.

The Infrastructure Can Span Many Physical Devices
The diagram shows many ESXi hosts and their physical servers aggregated to share resources.

A virtual infrastructure consists of the following components:

Bare-metal hypervisors to enable full virtualization of each x86 computer.

Virtual infrastructure services such as resource management to optimize available resources among virtual machines.

Automation solutions that provide special capabilities to optimize a particular IT process such as provisioning or disaster recovery.

In cloud computing, providers deliver hosted services on demand over the Internet. Cloud computing is similar to utilities like electricity and telephony. The user can consume the level of service needed at any time without being responsible for the production and management of the service.

A virtual infrastructure is the foundation for cloud computing. Cloud computing depends on a scalable and elastic model for delivering IT services, and the model itself depends on virtualization to be workable. VMware vSphere provides that virtualization.

Server consolidation through virtualization lets you get more out of your existing servers. It also lets you limit the physical resources that you need to manage, power, store, and buy. You achieve high consolidation ratios by consolidating existing workloads and leveraging remaining servers for the deployment of new applications and solutions.

In Server Consolidation, Physical Machines Are Converted to Virtual Machines to Run in a vSphere ESXi Host
The diagram shows six physical servers being consolidated onto a single server by being converted to virtual machines.

Virtualization enables IT to reduce or even eliminate planned and unplanned downtimes. For example, with vSphere you can migrate virtual machines live to another host and perform maintenance on physical servers anytime, without user or service disruption. Unplanned downtime is reduced by using vSphere features such as High Availability and Fault Tolerance.

Traditional disaster recovery plans require manual, complex steps to allocate recovery resources, perform bare metal recovery, recover data, and validate that systems are ready for use. VMware vSphere simplifies this environment. Hardware configuration, firmware, operating system, and applications become data stored in a few files on disk. Protecting these files using your backup or replication software means that the entire system is protected. These files can be recovered to any physical computer without requiring changes because virtual machines are hardware-independent.