text: **Target write with Multiple Target FlashCopy (Copy on Demand)**
  A write to an intermediate or the newest target volume must consider the state of the grain 
  within its own mapping, and the state of the grain of the next oldest mapping. Consider the 
  following points: 
  
  (cid:2) If the grain in the target that is being written is copied and if the grain of the next oldest 
  mapping is not yet copied, the grain must be copied before the write can proceed to 
  preserve the contents of the next oldest mapping. 
  
  For example, as shown in Figure 11-13 on page 454, if the grain “G” is changed on T2, 
  then it needs to be copied to T1 (next oldest not yet copied) first and then changed on T2. 
  
  (cid:2) If the grain in the target that is being written is not yet copied, the grain is copied from the 
  oldest copied grain in the mappings that are newer than the target, or from the source if 
  none is copied. For example, as shown in Figure 11-13 on page 454, if the red grain on T0 
  is written, then it will first be copied from T1 (data “E”). After this copy is done, the write 
  can be applied to the target. 