You can create a VM storage policy that is compatible with Virtual SAN or Virtual Volumes. You can then designate this policy as the default for Virtual SAN and Virtual Volumes datastores. The user-defined default policy replaces the default storage policy that VMware provides.
Each Virtual SAN and Virtual Volumes datastore can have only one default policy at a time. However, you can create a single storage policy with multiple rule sets, so that it matches multiple Virtual SAN and Virtual Volumes datastores. You can designate this policy as the default policy for all datastores.
When the VM storage policy becomes the default policy for a datastore, you cannot delete the policy unless you disassociate it from the datastore.