Specifications

Because virtual machines are decoupled from specific underlying physical hardware, virtualization allows you
to consolidate physical computing resources such as CPUs, memory, storage, and networking into pools of
resources that can be dynamically and flexibly made available to virtual machines. With appropriate
management software, such as vCenter Server, you can also use a number of features that increase the
availability and security of your virtual infrastructure.
Physical Topology of vSphere Datacenter
A typical VMware vSphere datacenter consists of basic physical building blocks such as x86 virtualization
servers, storage networks and arrays, IP networks, a management server, and desktop clients.
The vSphere datacenter topology includes the following components.
Compute servers
Industry standard x86 servers that run ESXi on the bare metal. ESXi software
provides resources for and runs the virtual machines. Each computing server
is referred to as a standalone host in the virtual environment. You can group a
number of similarly configured x86 servers with connections to the same
network and storage subsystems to provide an aggregate set of resources in
the virtual environment, called a cluster.
Storage networks and
arrays
Fibre Channel SAN arrays, iSCSI SAN arrays, and NAS arrays are widely used
storage technologies supported by VMware vSphere to meet different
datacenter storage needs. The storage arrays are connected to and shared
between groups of servers through storage area networks. This arrangement
allows aggregation of the storage resources and provides more flexibility in
provisioning them to virtual machines.
IP networks
Each compute server can have multiplephysical network adapters to provide
high bandwidth and reliable networking to the entire VMware vSphere
datacenter.
vCenter Server
vCenter Server provides a single point of control to the datacenter. It provides
essential datacenter services such as access control, performance monitoring,
and configuration. It unifies the resources from the individual computing
servers to be shared among virtual machines in the entire datacenter. It does
this by managing the assignment of virtual machines to the computing servers
and the assignment of resources to the virtual machines within a given
computing server based on the policies that the system administrator sets.
Computing servers continue to function even in the unlikely event that
vCenter Server becomes unreachable (for example, if the network is severed).
Servers can be managed separately and continue to run the virtual machines
assigned to them based on the resource assignment that was last set. After
connection to vCenter Server is restored, it can manage the datacenter as a
whole again.
Management clients
VMware vSphere provides several interfaces for datacenter management and
virtual machine access. These interfaces include VMware vSphere Client
(vSphere Client), vSphere Web Client for access through a web browser, or
vSphere Command-Line Interface (vSphere CLI).
vCenter Server and Host Management
12 VMware, Inc.