text: **3.11 Volume configuration**
  
  When planning a volume, consider the required performance, availability, and cost of storage 
  backing that volume. Volume characteristics are defined by the storage pool in which it is 
  created. 
  
  Every volume is assigned to an I/O Group that defines which pair of Storwize V7000 nodes 
  will service I/O requests to the volume. 
  
  **Important:**No fixed relationship exists between I/O Groups and storage pools. 
  
  **67** Chapter 3. Planning 