VMware vSAN is a hyperconverged, software-defined storage platform that is integrated with VMware vSphere. vSAN aggregates locally attached disk from the hosts participating in the vSphere cluster, creating a distributed shared vSAN datastore. vSAN is the first policy-driven storage solution from VMware that is designed for simplifying storage provisioning and management in vSphere environments. To achieve fault tolerance and performance, the virtual machines that are deployed on a vSAN datastore use VM level storage policy. For more information about vSAN, see VMware vSAN product page.
VMware provides two vSAN architectures named as vSAN Original Storage Architecture (OSA) and vSAN Express Storage Architecture (ESA) from vSphere 8.0. VMware vSAN OSA provides a two tier architecture consisting of a caching tier and a capacity tier. VMware provides two different configuration options for vSAN—All-Flash and Hybrid. The All-Flash configuration uses flash devices for both the cache layer and the capacity layer. The Hybrid configuration uses flash devices in cache layer for optimal performance and magnetic disk to increase the capacity and persistent data storage.
You can build a vSAN cluster by using one of the following options: