The following list contains facts about quorum configurations:
Quorum devices can contain user data.
In an N+1 configuration where N quorum devices are each connected to one of the 1 through N nodes and the N+1 node, the cluster survives the death of either all 1 through N nodes or any of the N/2 nodes. This availability assumes that the quorum device is functioning correctly.
In an N-node configuration where a single quorum device connects to all nodes, the cluster can survive the death of any of the N-1 nodes. This availability assumes that the quorum device is functioning correctly.
In an N-node configuration where a single quorum device connects to all nodes, the cluster can survive the failure of the quorum device if all cluster nodes are available.
For examples of quorum configurations to avoid, see Bad Quorum Configurations. For examples of recommended quorum configurations, see Recommended Quorum Configurations.