Failover Clustering Basics
Failover Clustering was first introduced in Windows NT 4, known then as Microsoft
Cluster Services, and it was developed under the very cool code name of Wolfpack.
Prior to Windows Server 2012, the clustering feature was available only in the
Enterprise and above SKUs of Windows Server. However, with the standardization of
features and scalability in Windows Server 2012 editions, the Failover Clustering
feature is now available in the Standard SKU in addition to Datacenter. Even with the
divergence of feature equality in Windows Server 2016 between Standard and
Datacenter, Failover Clustering is still present in the Standard edition and has all the
same features as its Datacenter bigger brother.
Failover Clustering is a feature and not a role in Windows Server, because clustering
just helps make another role more available. The difference between roles and
features is that a role, such as Hyper-V or File Services, designates the primary
purpose of a server. A feature, such as backup, BitLocker, and clustering, helps a
server perform its primary purpose.
Failover Clustering can be installed through Server Manager or through PowerShell as
follows:
Install-WindowsFeature Failover-Clustering
A cluster consists of two or more nodes that offer services to the network, as shown in
Figure 7.1. While the cluster itself has a name, IP address, configuration, and,
optionally, storage available to all nodes in the cluster, the actual services offered by
the cluster have their own resources, such as an IP address, network name, and disks
from those available to the cluster. The types of service offered by a cluster include file
servers, print servers, DHCP servers, Hyper-V virtual machines, or any other
application that has been written to be cluster aware, such as Exchange and SQL
Server.