Specifications

Host agent
On each managed host, the software that collects, communicates, and executes
the actions received through the vSphere Client. It is installed as part of the
ESXi installation.
LDAP
vCenter Server uses LDAP (Lightweight Directory Access Protocol) to
synchronize data such as license and role information across vCenter Server
systems joined in Linked Mode.
vSphere Managed Inventory Objects
In vSphere, the inventory is a collection of virtual and physical objects on which you can place permissions,
monitor tasks and events, and set alarms. You can group most inventory objects by using folders to more easily
manage them.
All inventory objects, with the exception of hosts, can be renamed to represent their purposes. For example,
they can be named after company departments or locations or functions. vCenter Server monitors and manages
the following components of your virtual and physical infrastructure:
Clusters
A collection of ESXi hosts and associated virtual machines intended to work
together as a unit. When you add a host to a cluster, the host’s resources become
part of the cluster’s resources. The cluster manages the resources of all hosts.
If you enable VMware EVC on a cluster, you can ensure that migrations with
vMotion do not fail because of CPU compatibility errors. If you enable vSphere
DRS on a cluster, the resources of the hosts in the cluster are merged to allow
resource balancing for the hosts in the cluster. If you enable vSphere HA on a
cluster, the resources of the cluster are managed as a pool of capacity to allow
rapid recovery from host hardware failures.
Datacenters
Unlike a folder, which is used to organize a specific object type, a datacenter is
an aggregation of all the different types of objects needed to do work in virtual
infrastructure: hosts, virtual machines, networks, and datastores.
Within a datacenter there are four separate hierarchies.
n
Virtual machines (and templates)
n
Hosts (and clusters)
n
Networks
n
Datastores
The datacenter defines the namespace for networks and datastores. The names
for these objects must be unique within a datacenter. For example, you cannot
have two datastores with the same name within a single datacenter, but you
can have two datastores with the same name in two different datacenters.
Virtual machines, templates, and clusters need not be unique within the
datacenter, but must be unique within their folder.
Objects with the same name in two different datacenters are not necessarily the
same object. Because of this, moving objects between datacenters can create
unpredictable results. For example, a network named networkA in
datacenterA might not be the same network as a network named networkA in
datacenterB. Moving a virtual machine connected to networkA from
datacenterA to datacenterB results in the virtual machine changing the network
it is connected to.
Chapter 1 vSphere Concepts and Features
VMware, Inc. 15