SRM technologies can be categorized into three levels: Volume allocation mechanisms determine which hosts can access which volumes.
Data management technologies allow administrators to manage storage resources across multiple devices. Application-oriented management tools manage storage from the perspective of applications and users.
At the top of the pyramid (the software area) we are interested in the volumes, the data, the applications. We are looking at the virtual paths to devices. What we are trying to establish is which application is storing what type of data on which volume. And the volume will be mapped through to a logical unit. The logical unit is more at the device side of things. This is about the logical relationships.