Figure 1 shows the SMS classes and groups that are assigned to data.

Figure 1. SMS and its relationship to a data set

The following example shows the different ways in which you can use SMS services. The storage administrator might define one storage class for DASD data sets requiring high performance and another for DASD data sets requiring standard performance. The administrator might define one storage class for objects requiring fast initial access response, which would place the objects on DASD, or another with lower initial access response, which would place objects on tape or optical media.

SMS automatically assigns new data to classes based on criteria that the storage administrator selects, such as data naming conventions. SMS assigns the data to an appropriate storage group of devices. SMS uses the values from the assigned classes to determine the space management, performance, and availability requirements of the data.