VMware ESXi Server

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What Does VMware ESXi Server Mean?

VMware ESXi Server is a bare metal (Type-1 ) hypervisor that was developed for vSphere, VMware’s server virtualization and container-based application development software. A hypervisor can be thought of as an operating system that allows multiple virtual machines, virtual appliances and containers to run efficiently on the same physical server.


ESXi is one of the two core components of vSphere, VMware's popular management system for containers and virtual machines (VMs). ESXi servers are managed by a VMkernel ( based on the Linux kernel) and installed directly on a local disk in the host machine. Whenever a VMkernel receives a request for resources, the kernel presents the request to the host’s physical hardware for fulfillment.

According to VMware's website, ESXi is targeted at enterprise organizations, small businesses and individual users. Enterprise licenses can be obtained as part of a paid vSphere edition. Small businesses and individuals can use a free vSphere Hypervisor edition of the server. Installation requires a host with at least two CPUs and a minimum of 4 GB of physical RAM.

Techopedia Explains VMware ESXi Server

VMware Inc. developed ESXi as a bare-metal embedded hypervisor, which means it runs directly on server hardware and does not require the installation of an additional underlying operating system. The virtualization software creates and runs its own kernel, which is run after a Linux kernel bootstraps the hardware. The resulting service is a microkernel, which has three interfaces:

  • Hardware
  • Guest system
  • Console operating system (service console)

Advantages of Using VMware's ESXi Server

The ESXi's centralized management features can streamline IT administration and its small code footprint reduces hardware requirements. This is what give ESXi the reputation of providing greater efficiency at a lower cost. With as little as 6TB of data, the VMware ESXi Server can run up to 128 virtual CPUs.

ESXi Server features

VMware ESXi Server features include:

  • Remote management tools.
  • Application programming interface (API) integration that eliminates the need for administrators to install and control third-party management agents.
  • A lightweight architecture and small code base.
  • Command line scripting environments.
  • Quick installation from a USB flash drive.
  • Simple security configurations.

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Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.