In clustering technology, the action of moving resources back to a node (a computer in a cluster) that has failed. This is sometimes known as «rebalancing the workload».
Suppose you have a cluster that has two nodes, each containing different resources. If Node A experiences failure, failover occurs and the workload of Node A (its set of resources) is transferred to Node B. When Node A reboots, it checks with Node B to see which resources are running on Node B and discovers that some of these cluster groups would “prefer” to reside on Node A.
At this point failback occurs, and the preferred groups are moved from Node B back to Node A. Failback might be configured to occur immediately or at a scheduled time if access to resources is low.
In Microsoft Windows NT 4 Enterprise Edition, Microsoft Cluster Server (MSCS) sets up and controls clustering. In Windows 2000 Advanced Server, the Cluster service makes these functions available.