text: **Note:**The Content Manager OnDemand cache storage on a hierarchical file system (HFS) 
  is not part of these SMS constructs. 
  
  **SMS storage group**
  An SMS*storage group*is a collection of storage volumes and attributes that are defined by 
  the installation. Storage groups, with storage classes, help reduce the requirement for users 
  to understand the physical characteristics of the storage devices that contain their data. 