text: In thick-provisioned environments (available on FlashSystem 900 and Storwize), this capacity 
  is allocated to a host whether it has data that is written. For thin-provisioned environments 
  (available on the Storwize), this data is written and used. This difference occurs because of 
  the different ways in which thick and thin provisioning use disk space. 
  
  These systems are available worldwide, but specific client and program differences exist by 
  location. Contact your IBM Business Partner or sales person for more information. 