The performance service is enabled at the cluster level, and it is important to remember that the performance history database is not a component of vCenter Server. The performance history database is stored as a vSAN object, independent of vCenter Server. A storage policy is assigned to the object to control space consumption, availability, and performance of that object. If the object becomes unavailable, performance history for the cluster is unavailable until access to the object is restored. The performance history database can consume up to 255 GB of capacity on the vSAN datastore.