Chapter 3A – VSAN-specific storage-policy options
VSAN provides multiple storage-policy options to help you define the best operating parameters for your VMs. They are described in detail here.
Number of failures to tolerate
This policy option defines how many node failures your object should survive (or how many fault domains can be lost in vSphere 6.0). Node-failure tolerance is achieved by building mirrors of your objects. Those mirrors are distributed throughout the cluster in such a way that the specified number of hosts can fail. To accomplish this, VSAN will create n+ 1 copies of the data, where n is the number of failures to tolerate.
Limitations
As quorum-based availability for an object requires that >50 percent of all data components and witnesses be available (see Appendix B, Additional VSAN Information), specifying more failures to tolerate requires a larger number of hosts. While VSAN will create n+1 copies of the data, it requires 2n+1 nodes with storage capacity to...
