Each object is composed of a set of components, determined by capabilities that are in use in the VM Storage Policy. For example, with Primary level of failures to tolerate set to 1, vSAN ensures that the protection components, such as replicas and witnesses, are placed on separate hosts in the vSAN cluster, where each replica is an object component. In addition, in the same policy, if the Number of disk stripes per object configured to two or more, vSAN also stripes the object across multiple capacity devices and each stripe is considered a component of the specified object.
vSAN 6.0 and later maintains a quorum by using an asymmetrical voting system where each component might have more than one vote to decide the availability of objects. Greater than 50 percent of the votes that make up a VM’s storage object must be accessible at all times for the object to be considered available. When 50 percent or fewer votes are accessible to all hosts, the object is no longer accessible to the vSAN datastore. Inaccessible objects can impact the availability of the associated VM.
An object is considered unhealthy when no full mirror is available or the minimum required number of data segments are unavailable for RAID 5 or RAID 6 objects. If fewer than 50 percent of an object's votes are available, the object is unhealthy. Multiple failures in the cluster can cause objects to become unhealthy. When the operational status of an object is considered unhealthy, it impacts the availability of the associated VM.
If the stripe width is configured with 1, the number op replica components minus the stripe width is the number of witness components.
IF SW=1 THEN C-SW=W
