Force Quorum in a Single-Site or Multi-Site Failover Cluster
Updated: October 20, 2011
Applies To: Windows Server 2008
You can force quorum in a single-site or multi-site cluster. Forcing quorum means that you start the cluster even though only a minority of the elements that are required for quorum are in communication.
This command is important to know for multi-site clusters with an odd number of nodes. The recommended design for a multi-site cluster has an even number of nodes, but it is possible to create a multi-site design using an odd number of nodes, with the majority of nodes at the main site. As with all configurations with an odd number of nodes, such a design should use the Node Majority quorum configuration. If you use this design and the main site goes down, to start the secondary site (which has a minority of the nodes) you will need to force quorum, that is, force all nodes which can communicate with each other to begin working together as a cluster.
To force quorum in a single-site or multi-site cluster
- On a node that contains a copy of the cluster configuration that you want to use, open a Command Prompt window.
The choice of node can be important when you are forcing quorum, because one node could potentially have an older copy of the cluster configuration database than another node or nodes. The cluster will use the copy of the cluster configuration that is on the node on which you perform this procedure. The cluster will then replicate that copy to all other nodes.
On that node, type the following command:
net start clussvc /fq
To open a Command Prompt window, click Start, right-click Command Prompt, and then either click Run as administrator or click Open. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
When a cluster is forced to start without quorum it continually looks to add nodes to the cluster and is in a special “forced” state. Once it has majority, the cluster moves out of the forced state and behaves normally, which means it is not necessary to rerun the command without the /fq option. If the cluster moves out of the forced state, loses a node, and drops below quorum, it will go offline again. At that point, to bring it online again while it does not have quorum would require running the command again with the /fq option.