Beginning with VxRail 7.0.300, the VxRail 2-node cluster supports nested fault domains, where each host or a group of hosts can redundantly store VM object replicas. In a 2-node cluster configuration, fault domains can be created on a per-disk-group level, enabling disk-group-based data replication. Thus, each of the two data nodes can host multiple object replicas. With this secondary level of resilience, the 2-node cluster can ensure data availability if more than one device fails. For instance, one host failure and an additional device or disk group failure will not impact the data availability of the VMs that have a nested fault domain policy applied. A minimum of three disk groups per host are required to serve the nested level of fault tolerance.
