Dealing with a failover situation

Last published : Aug 05, 2026
In summary, the site scenarios that can occur when there is a cluster server failure include the following possibilities:
  • If the site not owning the quorum volume and the cluster goes offline, the quorum and data volumes stay online at the other site and other cluster resources stay online or move to that site. Storage Foundation allows the owning cluster node to remain online with 50% ownership of the disks in the quorum group.
  • If the site owning the quorum volume goes offline, the remaining site cannot gain control of the quorum volume because it cannot reserve a majority of disks in the quorum group. This is a safeguard to prevent multiple nodes from onlining members of a cluster disk group to which they have access.
    Caution: Manual failover of a cluster between two sites should be performed only after coordination between the two sites to ensure that the primary server has actually failed. If you manually import a cluster disk group containing the Microsoft clustering quorum to the secondary (failover) server when the primary server is still active, this causes a split-brain situation. If the split-brain situation occurs, you may lose data because each plex of the mirrored volume may be updated independently when the same disk group is imported on both nodes.