Host pinning: local copy only
Replicas: 0-3 Replicas (1N-4N) at each active site
Erasure Coding: RAID5-6 at each active site
vSAN 6.7 introduces the Host Pinning storage policy that can be used for next-generation, shared-nothing applications. When using Host Pinning, vSAN maintains a single copy of the data and stores the data blocks local to the ESXi host running the VM. This policy is offered as a deployment choice for Big Data (Hadoop, Spark), NoSQL, and other such applications that maintain data redundancy at the application layer. vSAN Host Pinning has specific requirements and guidelines that require VMware validation to ensure proper deployment.
VMware vSAN 6.6 introduced enhanced stretched cluster availability with Local Fault Protection. You can provide local fault protection for virtual machine objects within a single site in a stretched cluster. You can define a Primary level of failures to tolerate for the cluster, and a Secondary level of failures to tolerate for objects within a single site. When one site is unavailable, vSAN maintains availability with local redundancy in the available site.
In the case of stretched clustering, selecting 0 replicas means that there is only one instance of the data available at each of the active sites.
Local Fault Protection is only available in the Enterprise editions of vSAN.
VMware, vSAN [SDS]/6.7 U3, ROBO Ent
SC Data Redundancy, Disaster Recovery, Data Availability