A data storage management system comprises enhanced capabilities for automatically discovering operational characteristics of data storage devices installed in the system. A user interface enables end-users to submit requests for storage resources ranging from a simple request for a certain amount of storage space to more complex requests that specify the type of storage technology, the manufacturer, the I/O speed of the storage device, etc. The end-user also may include an expiration timeframe for the requested storage space. The system identifies storage devices that are suitable to the end-user's request, automatically provisions the storage space (e.g., LUN), and assigns it to the requestor. The assigned storage space may automatically expire, based on user-requested or system-provided expiration timeframes. Expired storage space is returned to a logical pool of available resources so that it may be assigned in response to other requests. The system comprises special-purpose policies that govern which data storage devices may be used for users submitting requests and further specify other administrative constraints.