text: **3.6 SAN configuration planning**
  
  Storwize V7000 cluster can be configured with a minimum of two (and up to eight) Storwize 
  V7000 nodes. These nodes can use SAN fabric to communicate with back-end storage 
  subsystems and hosts. 
  
  **3.6.1 Physical topology**
  
  The switch configuration in an Storwize V7000 fabric must comply with the switch 
  manufacturer’s configuration rules, which can impose restrictions on the switch configuration. 
  For example, a switch manufacturer might limit the number of supported switches in a SAN. 
  Operation outside of the switch manufacturer’s rules is not supported. 