text: All functions follow an enclosure-based licensing scheme. Use the following guidelines to 
  ensure that you are licensing the correct number of enclosures: 
  
  – External Virtualization 
  
  The system does not require a license for its own control and expansion enclosures. 
  However, a license is required for each enclosure of any external storage systems 
  being virtualized. For example, if the system is made up of one control enclosure, one 
  expansion enclosure, and one virtualized storage system that is made up of two 
  enclosures, two licenses are required. The system does not require an external 
  virtualization license for external enclosures that are only being used to provide 
  managed disks for a quorum disk and are not providing any capacity for volumes. 
  
  – Remote Mirroring, Real-time Compression, or Transparent Cloud Tiering 
  
  The total number of enclosures must include the enclosures on external storage 
  system licensed for virtualization plus the number of control and expansion enclosures 
  that are part of your local system. For example, if the system is made up of one control 
  enclosure, one expansion enclosure, and one virtualized storage system that is made 
  up of two enclosures, four licenses are required. Only Storwize V7000 Gen2 and 
  Storwize V7000 Gen2+ models support transparent cloud tiering. 