text: **11.2.18 Memory allocation for FlashCopy**
  
  Copy Services features require that small amounts of volume cache be converted from cache 
  memory into bitmap memory to allow the functions to operate at an I/O group level. If you do 
  not have enough bitmap space allocated when you try to use one of the functions, you cannot 
  complete the configuration. The total memory that can be dedicated to these functions is not 
  defined by the physical memory in the system. The memory is constrained by the software 
  functions that use the memory. 
  
  For every FlashCopy mapping that is created on an IBM Spectrum Virtualize system, a 
  bitmap table is created to track the copied grains. By default, the system allocates 20 MiB of 
  memory for a minimum of 10 TiB of FlashCopy source volume capacity and 5 TiB of 
  incremental FlashCopy source volume capacity. 