text: This section describes these scenarios. 
  
  **Node failure**
  Normally, two copies of the FlashCopy bitmap are maintained. One copy of the FlashCopy 
  bitmap is on each of the two nodes that make up the I/O Group of the source volume. When a 
  node fails, one copy of the bitmap for all FlashCopy mappings whose source volume is a 
  member of the failing node’s I/O Group becomes inaccessible. 
  
  FlashCopy continues with a single copy of the FlashCopy bitmap that is stored as non-volatile 
  in the remaining node in the source I/O Group. The system metadata is updated to indicate 
  that the missing node no longer holds a current bitmap. When the failing node recovers or a 
  replacement node is added to the I/O Group, the bitmap redundancy is restored. 
  
  **Path failure (Path Offline state)**
  In a fully functioning system, all of the nodes have a software representation of every volume 
  in the system within their application hierarchy. 
  
  Because the storage area network (SAN) that links IBM SAN Volume Controller nodes to 
  each other and to the MDisks is made up of many independent links, it is possible for a subset 
  of the nodes to be temporarily isolated from several of the MDisks. When this situation 
  happens, the managed disks are said to be*Path Offline*on certain nodes. 