In our SQL Failover Cluster Instance (FCI) environments (overall environment description available here) we generally use 2 servers plus a disk witness (quorum drive) – we only have one data center so we don’t take the overhead of using node majority.  That quorum drive is part of the resource group called “Cluster Group”, commonly known as cluster core resources.  The core cluster resources have no relationship with any other cluster resources (e.g. the SQL Server resource), and they can fail over independently from any other cluster resource. They also stay in place if someone fails over the other resources (i.e. SQL). Continue reading