text: Figure 2-9 Rear of IBM Storwize V7000 expansion enclosure 
  
  **SAS chain limitations**
  When attaching expansion enclosures to the control enclosure, you are not limited by type of 
  the enclosure (if it meets all generation level restrictions). The only limitation for each SAS 
  chain is its*chain weight*. Each type of enclosure defined its own chain weight: 
  
  (cid:2) Enclosures 12F and 24F have a chain weight of 1 
  (cid:2) Enclosure 92F has a chain weight of 2.5 
  
  The maximum chain weight is 10. 
  
  For example, you can combine seven 24F and one 92F expansions (7x1 + 1x2.5 = 9.5 chain 
  weight), or two 92F enclosures, one 12F, and four 24F (2x2.5 + 1x1 + 4x1 = 10 chain weight). 