split brain syndrome

Split brain syndrome occurs when all networks designated to carry internal cluster communications fail, and nodes cannot receive heartbeat signals from each other. [Exchange 2007]

When a cluster reforms with equal numbers of nodes at each site, and each half of the cluster thinks it is the authority and starts up the same set of applications, and tries to modify the same data, resulting in data corruption. Serviceguard architecture prevents split-brain syndrome in all cases unless dual cluster locks are used.