text: External LUs can have one of the following modes on Storwize V7000: 
  
  (cid:2)*Unmanaged*
  
  External MDisks are discovered by the system as unmanaged MDisks. An unmanaged 
  MDisk is not a member of any storage pool. It is not associated with any volumes, and has 
  no metadata stored on it. The system does not write to an MDisk that is in unmanaged 
  mode, except when it attempts to change the mode of the MDisk to one of the other 
  modes. 
  
  (cid:2)*Managed*
  
  When unmanaged MDisks are added to storage pools, they become managed. Managed 
  mode MDisks are always members of a storage pool, and their extents contribute to the 
  storage pool. This mode is the most common and normal mode for an MDisk. 
  
  (cid:2)*Image*
  
  Image mode provides a direct block-for-block translation from the MDisk to a volume. This 
  mode is provided to satisfy the following major usage scenarios: 
  
  – Virtualization of external LUs that contain data that was not written through the 
  Storwize V7000. 
  
  – Exporting MDisks from the Storwize V7000 after migration of volumes to image mode 