This section shows examples of quorum configurations that are recommended.
Two quorum votes are required for a two-node cluster to form. These two votes can derive from the two cluster nodes, or from just one node and a quorum device.
Figure 3-2 Two–Node Configuration
Quorum devices are not required when a cluster includes more than two nodes, as the cluster survives failures of a single node without a quorum device. However, under these conditions, you cannot start the cluster without a majority of nodes in the cluster.
You can add a quorum device to a cluster that includes more than two nodes. A partition can survive as a cluster when that partition has a majority of quorum votes, including the votes of the nodes and the quorum devices. Consequently, when adding a quorum device, consider the possible node and quorum device failures when choosing whether and where to configure quorum devices.) QD1. C/D -> QD2. Config2: HostA-C. A/C -> QD1. B/C -> QD2. Config3: HostA-C -> one QD.>