Quorum Disk

A quorum has to be present for a cluster to be functional as a cluster is a group of servers. A quorum is defined as N/2 + 1 servers in the cluster are up and running. N is the total number of servers in the cluster. To avoid a split-brain scenario for a cluster with an even number of servers, in the case where half of the members of the cluster lose communication with the other half of the members of the cluster, a quorum disk is used to determine which partition has the quorum for remaining in the cluster.

Because a server cluster has to be functional even when an SME cluster fails, it is important that the quorum disk not be configured as a crypto disk.