Quorum

Microsoft Platform Guide
Audience
Public
Source Type
Documentation

When nodes fail, or when some subset of nodes loses contact with another subset, surviving nodes need to verify that they constitute the majority of the cluster to remain online. If they can't verify that, they'll go offline. Depending on the number of nodes, a witness is required, recommended, or not necessary. The witness can be a disk, or a file share on-premises or in the cloud. A cluster with 4 or fewer nodes should have a witness. See Cluster quorum overview for details.

Disk Witness

The easiest quorum to configure is a disk witness. First provision a volume on the FlashArray, connect it to the cluster, and then add it to the cluster as demonstrated in the last section. A disk witness must be at least 512MB.

  1. Open Failover Cluster Manager and right-click the cluster name in the left pane. Select More Actions, and then click Configure Cluster Quorum Settings. Select the Quorum Witness, then select the disk you just added to the cluster.

  2. In Failover Cluster Manager, the status of the cluster disk will change from Available Storage to Disk Witness in Quorum.

File Share Witness

  1. To designate a File Share Witness for a cluster, first create a file share on a server outside of the cluster.

  2. Create a folder on an available drive and right-click it in Windows Explorer and select properties. Click Advanced Sharing.

  3. Click Share this folder and then click Caching. After configuring Caching click on Permissions.

  4. Select ‘No files or programs from the shared folder are available offline’. Click OK, then click Permissions.

    1. Ensure No Files or programs from the shared folder are available offline, is selected.

  5. In Permissions, select Add, then OK.

    1. Add a new Permission to the share.

  6. Next type the name of the cluster in the box and select the Object Types button. Computer names are not in the default list of object types.

  7. Check the Computers object type and click OK.

  8. Click Check Names. If the cluster is properly registered in Active Directory, it will find the Computer Object. Select OK.

  9. Check Full Control for the Cluster Computer Object and OK.

    1. Give the Cluster Computer Object Full Control to the share.

  10. Open Failover Cluster Manager and right-click the cluster name in the left pane. Select More Actions, and then click Configure Cluster Quorum Settings. Select the Quorum Witness, then select the disk you just added to the cluster.

  11. Choose Select the Quorum Witness, then select Configure a file share witness. Next, enter the path to the new file share.

  12. Click next and the file share witness is configured.

  13. In Failover Cluster Manager, click on the cluster name in the left pane to see the Quorum status.