text: In an OAM environment, object storage groups allow the storage administrator to define an 
  object storage hierarchy. The object storage hierarchy classifies storage areas according to 
  location and, therefore, according to retrieval response time. Each object storage hierarchy 
  must contain an object directory, containing control information about each object. 
  Additionally, the hierarchy can have the following items: 
  
  (cid:2) DB2 object storage tables on a hard disk drive 
  
  (cid:2) Optical volumes that are associated with optical libraries (real or pseudo), and stand-alone 
  or operator-accessible optical disk drives 
  
  (cid:2) Tape volumes that are associated with tape libraries or stand-alone tape drives 
  
  **SMS management class**
  Management classes define the space and availability requirements for datasets. Class 
  attributes control backup, migration, retention of data, and release of unused space. OSMC 
  uses information from the management classes to determine the automatic management 
  processes that need to be performed on corresponding OAM objects. 
  
  **Automated Class Selection routine**
  Automated Class Selection (ACS) routines are used to assign class and storage group 
  definitions to datasets and objects. ACS routines are written in the ACS language, which is a 
  high-level programming language that is similar to the language that is used for the 
  construction of TSO CLISTs. The ACS translator is used to convert the routines to object form 
  so that they can be stored in the SMS configuration. 