text: **1.1 Storage virtualization terminology**
  
  *Storage virtualization*is a term that is used extensively throughout the storage industry. It can 
  be applied to various technologies and underlying capabilities. In reality, most storage devices 
  technically can claim to be virtualized in one form or another. Therefore, this chapter starts by 
  defining the concept of storage virtualization as it is used in this book. 
  
  IBM describes storage virtualization in the following way: 
  
  (cid:2) Storage virtualization is a technology that makes one set of resources resemble another 
  set of resources, preferably with more desirable characteristics. 
  
  (cid:2) It is a logical representation of resources that is not constrained by physical limitations and 
  hides part of the complexity. It also adds or integrates new function with services and can 
  be nested or applied to multiple layers of a system. 
  
  Storage virtualization is also defined in the Storage Networking Industry Association’s (SNIA) 
  shared storage model version 2, as shown in Figure 1-1. 