text: For more information about layers and how to change them, see IBM Knowledge Center. 
  
  **Fibre Channel external storage controllers**
  A controller connected through Fibre Channel is detected automatically by the system, 
  provided that the cabling, the zoning, and the system layer are configured correctly. 
  
  If the external controller is not detected, ensure that the Storwize V7000 is cabled and zoned 
  into the same storage area network (SAN) as the external storage system. Check that layers 
  are set correctly on both virtualizing and virtualized systems if they belong to the IBM 
  Storwize family. 
  
  After the problem is corrected, use**Actions**→**Discover Storage**button found in**Pools**→ 
  **External Storage**, as shown in Figure 6-49, to rescan the Fibre Channel network. 