text: **FlashCopy service**
  FlashCopy service is a copy service that duplicates the contents of a source volume on a 
  target volume. In the process, the original contents of the target volume are lost. See also 
  “Point-in-time copy” on page 782. 
  
  **Flash drive**
  A data storage device that uses solid-state memory to store persistent data. 
  
  **Flash module**
  A modular hardware unit that contains flash memory, one or more flash controllers, and 
  associated electronics. 
  
  **Front end and back end**
  The IBM Storwize V7000 takes MDisks to create pools of capacity from which volumes are 
  created and presented to application servers (hosts). The volumes that are presented to the 
  hosts are in the front end of IBM Storwize V7000. 
  
  **Global Mirror**
  Global Mirror (GM) is a method of asynchronous replication that maintains data consistency 
  across multiple volumes within or across multiple systems. Global Mirror is generally used 
  where distances between the source site and target site cause increased latency beyond 
  what the application can accept. 
  
  **Global Mirror with change volumes**
  Change volumes are used to record changes to the primary and secondary volumes of a 
  remote copy relationship. A FlashCopy mapping exists between a primary and its change 
  volume, and a secondary and its change volume. 