Dynamic Witness in Windows Server 2012
Witness server plays there role when there is even number of nodes. If you have odd number of nodes and if any nodes fails it will turn into even number of nodes
The Dynamic Witness features which launched in Windows Server 2012 will helps to overcome the issue on enabling the witness server and providing their votes.
Hence clustering service will automatically assign the witness a vote, the witness dynamic vote, depending on if there is an odd or even number of votes present for the cluster nodes.
If there are an even number of nodes that have a vote (dynamic weight = 1), then the witness dynamic vote = 1
If there are an odd number of nodes that have a vote (dynamic weight = 1), then the witness dynamic vote = 0
To check the vote status of the witness, use the Windows PowerShell command below. A return of 1 means the witness has a vote; a return of 0 means the witness doesn’t have a vote. This is a read-only value. It simply shows the vote status of the witness.