text: **Metadata**
  In a standard pool, the system uses the real capacity to store data that is written to the 
  volume, and metadata that describes the thin-provisioned configuration of the volume. 
  Metadata uses volume real capacity and usually needs less than 0.5% of virtual capacity to 
  store its data. 
  
  This means that if your host used 100% of virtual capacity, some extra space is required on 
  your storage pool to store thin provisioning metadata. In a worst case, the real size of a thin 
  provisioned volume can be 100.5% of its virtual capacity. 
  
  In a data reduction pool, metadata for a thin provisioned volume is stored separately from 
  user data, and does not count in the volumes real capacity. 