text: **8.3 N-Port Virtualization ID support**
  
  The usage model for the Storwize V7000 is based on a two-way active/active node model. 
  This is a pair of distinct control modules that share active/active access for any specific 
  volume. These nodes each have their own Fibre Channel worldwide node name (WWNN). 
  Therefore, ports that are presented from each node have a set of worldwide port names 
  (WWPNs) that are presented to the fabric. 
  
  Traditionally, if one node fails or is removed for some reason, the paths that are presented for 
  volumes from that node go offline. In this case, it is up to the native O/S multipathing software 
  to fail over from using both sets of WWPN to only those that remain online. Although this 
  process is what multipathing software is designed to do, occasionally it can be problematic, 
  particularly if paths are not seen as coming back online for some reason. 
  
  Starting with Storwize V7000 V7.7, the system can be enabled into N_Port ID Virtualization 
  (NPIV) mode. When NPIV mode is enabled on the Storwize V7000 system, ports do not 
  come online until they are ready to service I/O, which improves host behavior around node 
  unpends. In addition, path failures because of an offline node are masked from hosts and 
  their multipathing driver do not need to perform any path recovery. 