You can create a VM storage policy that is compatible with Virtual SAN or Virtual Volumes, and designate this policy as the default for Virtual SAN and virtual datastores. The user-defined default policy replaces the default storage policy that VMware provided.
Each Virtual SAN and virtual datastore can have only one default policy at a time. However, you can create a single storage policy that matches multiple Virtual SAN and Virtual Volumes datastores and designate it 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.