text: A volume that is created without the autoexpand feature, and therefore has a zero 
  contingency capacity, goes offline when the real capacity is used and it must expand. 
  
  To facilitate management of the auto expansion of thin-provisioned volumes, a capacity 
  warning should be set for the storage pools from which they are allocated. When the used 
  capacity of the pool exceeds the warning capacity, a warning event is logged. For example, if 
  a warning of 80% is specified, an event is logged when 20% of the pool capacity remains free. 
  
  A thin-provisioned volume can be converted nondisruptively to a fully allocated volume (or 
  vice versa) by using the volume mirroring function. You can create a thin-provisioned copy to 
  a fully allocated primary volume and then remove the fully allocated copy from the volume 
  after they are synchronized. 
  
  The fully allocated-to-thin-provisioned migration procedure uses a zero-detection algorithm 
  so that grains that contain all zeros do not cause any real capacity to be used. 
  
  **7.1.9 Compressed volumes**
  
  This custom type of volume is where data is compressed as it is written to disk, which saves 
  more space. To use the compression function, you must obtain the IBM Real-time 
  Compression license. 