VSAN 6.0 introduces a feature that allows for user-configurable fault domains. As opposed to VSAN 5.5, where each host is its own fault domain, VSAN 6.0 allows hosts to be grouped together into fault domains that act as one unit for the failures-to-tolerate policy calculation.

This can be extremely useful in larger clusters or clusters that may share a common point of failure within the datacentre. For example, if we have a six-node VSAN cluster where two nodes are in each of three racks, each rack may represent a hardware failure domain because the rack may be susceptible to power-distribution failures or a top-of-rack switch failure that neighboring racks may survive. VSAN 6.0 fault domains allow us to group the hosts in such a way that we can combine hosts that are likely to fail together into a single fault domain. This can improve cluster survivability by permitting multiple node failures without affecting data availability.

As noted previously, if we opt to use...