text: As with RACE, the new implementation uses the same Lempel-Ziv (LZ) based real-time 
  compression and decompression algorithm. However, in contrast to RACE compression, 
  DRP compression operates on smaller block sizes, which results in more performance gains. 
  
  The third benefit of DRP comes in the form of performance improvements because of Easy 
  Tier. 
  
  The metadata of data reduction pools does not fit in RAM; therefore, it is stored on disk on 
  metadata volumes, which are separate from data volumes. The metadata volumes of data 
  reduction pools are small and frequently accessed. They are good candidates for promotion 
  through Easy Tier. In contrast, data volumes are large, but because the metadata is stored 
  separately, Easy Tier can accurately identify frequently used data. Performance gains are 
  expected because Easy Tier promotes metadata to the fastest available storage tier. 
  
  DRPs support end-to-end SCSI Unmap functionality. Space that is freed from the hosts is a 
  process called*unmap*. A host can issue a small file unmap (or a large chunk of unmap space 
  if you are deleting a volume that is part of a data store on a host) and these result in the 
  freeing of all the capacity allocated within that unmap. Similarly, deleting a volume at the DRP 
  level frees all of the capacity back to the pool. 