vSAN is a distributed layer of software that runs natively as a part of the ESXi hypervisor. vSAN aggregates local or direct-attached storage disks of a host cluster and creates a single storage pool shared across all hosts of the cluster.
While supporting VMware features that require shared storage, such as HA, vMotion, and DRS, vSAN eliminates the need for an external shared storage and simplifies storage configuration and virtual machine provisioning activities.
You can use ESXCLI commands to retrieve vSAN information, manage vSAN clusters, perform network management, add storage, set the policy, and perform other monitoring and management tasks. Type esxcli vsan --help
for a complete list of commands.