Where is a Virtual SAN Fault Domain configured?
VMware Virtual SAN Cluster configuration
VMware High Availability Cluster configuration
Distributed Resource Scheduler configuration
Datacenter Advanced Settings configuration
If your Virtual SAN cluster spans across multiple racks or blade server chassis in a data center and you want to make sure that your hosts are protected against rack or chassis failure, you can create fault domains and add one or more hosts to it.
A fault domain consists of one or more Virtual SAN hosts grouped together according to their physical location in the data center. When configured, fault domains enable Virtual SAN to tolerate failures of entire physical rack as well as failures of a single host, capacity device, network link or a network switch dedicated to fault domains.
Fault domains cannot be configured for stretched or metro clusters.
The number of failures your cluster can tolerate depends on the number of failures a virtual machine is provisioned to tolerate. For example, when a virtual machine is configured with Number of failures to tolerate=1
and using multiple fault domains, Virtual SAN can tolerate a single failure of any kind and of any component in a fault domain, including the failure of an entire rack.
When you configure fault domains on a rack and provision a new virtual machine, Virtual SAN ensures that protection objects, such as replicas and witnesses are placed on different fault domains. If, for example, a virtual machine’s storage policy is Number of failures to tolerate=n, Virtual SAN requires a minimum of 2*n+1
fault domains in the cluster. When virtual machines are provisioned in a cluster with fault domains using this policy, the copies of the associated virtual machine objects are stored across separate racks.