text: **3.15.2 Combining FlashCopy and Metro Mirror or Global Mirror**
  
  Use of FlashCopy in combination with Metro Mirror or Global Mirror is allowed if the following 
  conditions are met: 
  
  (cid:2) A FlashCopy mapping must be in the idle_copied state when its target volume is the 
  secondary volume of a Metro Mirror or Global Mirror relationship. 
  
  (cid:2) A FlashCopy mapping cannot be manipulated to change the contents of the target volume 
  of that mapping when the target volume is the primary volume of a Metro Mirror or Global 
  Mirror relationship that is actively mirroring. 
  
  (cid:2) The I/O group for the FlashCopy mappings must be the same as the I/O group for the 
  FlashCopy target volume. 
  
  **3.15.3 Planning for Metro Mirror and Global Mirror**
  
  Metro Mirror is a copy service that provides a continuous, synchronous mirror of one volume 
  to a second volume. The systems can be up to 300 kilometers (186.4 miles) apart. Because 
  the mirror is updated synchronously, no data is lost if the primary system becomes 
  unavailable. Metro Mirror is typically used for disaster-recovery purposes, where it is 
  important to avoid any data loss. 
  
  Global Mirror is a copy service that is similar to Metro Mirror, but copies data asynchronously. 
  You do not have to wait for the write to the secondary system to complete. For long distances, 
  performance is improved compared to Metro Mirror. However, if a failure occurs, you might 
  lose data. 