A datastore cluster is a collection of datastores. Datastore clusters aggregate storage resources as with clusters of ESXi hosts.
vSphere Storage DRS™ (SDRS) provides initial placement and ongoing balancing recommendations to datastores in a Storage DRS-enabled datastore cluster.
The Datastore cluster feature enables the support of SDRS-enabled datastore clusters for the product. It allows migrating and provisioning virtual machines to SDRS-enabled datastore clusters.
The datastore cluster support is turned on by default.