Specifications

Table 2. Comparison of Multiple and Single Host Management (Continued)
Feature vCenter Server ESX
Power savings Possible with VMware Distributed Power
Management (DPM)
Not available
Centralized access control Available with Active Directory
Integration
Not available
vSphere and vCenter Server
VMware vSphere is a suite of virtualization applications that includes ESXESXi and vCenter Server.
vSphere uses virtualization to do the following tasks:
n
Run multiple operating systems on a single physical machine simultaneously.
n
Reclaim idle resources and balance workloads across multiple physical machines.
n
Work around hardware failures and scheduled maintenance.
Familiarity with the components that make up a vSphere environment helps you understand the setup process
and, ultimately, the process of using VMware vCenter Server to manage hosts and run virtual machines.
vSphere includes the following components:
vSphere includes the following components in addition to the ESX host and vSphere Client you have already
setup:
vSphere includes the following components in addition to the ESXi host and vSphere Client you have already
setup:
The vSphere Client
The vSphere Client is the interface to vCenter Server and hosts. It also provides
console access to virtual machines.
VMware vCenter Server
vCenter Server unifies resources from individual hosts so that those resources
can be shared among virtual machines in the entire datacenter. It accomplishes
this by managing the assignment of virtual machines to the hosts and the
assignment of resources to the virtual machines within a given host based on
the policies that the system administrator sets.
vCenter Server allows the use of advanced vSphere features such as VMware
Distributed Resource Scheduler (DRS), VMware High Availability (HA), and
VMware VMotion.
Datacenter
A datacenter is a structure under which you add hosts and their associated
virtual machines to the inventory.
Host
A host is a computer that uses ESXi virtualization software to run virtual
machines. Hosts provide CPU and memory resources, access to storage, and
network connectivity for virtual machines that reside on them.
Host
A host is a computer that uses ESX virtualization software to run virtual
machines. Hosts provide CPU and memory resources, access to storage, and
network connectivity for virtual machines that reside on them.
Virtual Machine
A virtual machine is a software computer that, like a physical computer, runs
an operating system and applications. Multiple virtual machines can run on
the same host at the same time. Virtual machines that vCenter Server manages
can also run on a cluster of hosts.
Figure 3 shows the relationships among the basic components of vSphere and how vCenter Server can be used
to manage hosts and run virtual machines.
Getting Started with ESXi Installable
24 VMware, Inc.