Number of Nodes

Each cluster uses the concept of a "quorum node set" to determine which nodes control the cluster.
In simple terms this means that we need an odd number of participants in any "quorum vote" to ensure that one quorum node set can win that vote.
In a cluster with an even number of nodes we can use a "witness" (a shared disk or a file share) to meet that requirement.
We can avoid this by using an odd number of voting nodes.  

Note that we can control whether a node has a vote.
A four node cluster with only three voting nodes is possible, as is a three node cluster with two voting nodes and a witness.

Enable Failover Clustering

Windows 2012

Server Manager - Manage - Add Roles and Features

Alternate PowerShell Method

You can install WSFC using...

Install-WindowsFeature -Name Failover-Clustering –IncludeManagementTools - restart

Validate Configuration

Common Errors

Create Cluster

Validate Configuration

Connect to Cluster

Cluster Quorum Configuration

• The witness file share must not be on a node that already participates in the WSFC configuration

• The witness file share can be a share from a node that participates in another WSFC configuration

• The witness file share must exist in the same Active Directory Domain as the WSFC

• The WSFC cluster service account must have read and write permissions to the witness file share

PowerShell

Quorum configuration can also be handled using PowerShell...

Get-ClusterQuorum

Set-ClusterQuorum -NodeMajority

Set-ClusterQuorum -NodeAndFileShareMajority \\myserver\myshare

To check vote settings...

Get-ClusterNode | fl NodeName, NodeWeight

To change vote settings...

Get-ClusterNode "MYNODE3").NodeWeight=0

Next Steps

Bibliography