text: Figure 2-2 IBM Spectrum Storage virtualization 
  
  The following reasons are the five top reasons to choose software-defined storage 
  virtualization infrastructure and benefit from IBM Spectrum Virtualize: 
  
  (cid:2) Lower license cost. Avoid purchasing licenses from multiple storage vendors for advanced 
  features (replication, tiering, snapshots, compression, and so on) of each external storage 
  subsystem. Manage them centrally from IBM Spectrum Virtualize. 
  
  (cid:2) Feed more data on physical disks. External SAN disk arrays have physical boundaries. 
  
  Although one subsystem might run out of space, another has free capacity. Virtualization 
  removes these boundaries. 
  
  (cid:2) Choose lower-cost disk arrays. Less-demanding applications can easily run on cheaper 
  disks with lower performance. IBM Spectrum Virtualize automatically and transparently 
  moves data up and down between low-performance and high-performance disk arrays 
  (tiering). 
  
  (cid:2) Cloud FlashCopy. IBM Spectrum Virtualize has an interface to the external cloud service 
  providers. IBM Spectrum Cloud FlashCopy supports full and incremental backup and 
  restore from cloud snapshots. 