Abstract: A method for selecting data storage media for demount in an automated storage library, and an automated storage library and program product therefor are disclosed. Preemptive demount of storage media is permitted when all peripheral storage devices in the library are occupied and one or more of such devices remains inactive for a predetermined time. Storage media may be demounted to service existing mount requests, provided the peripheral storage devices in which the media are mounted are inactive. There is also a need, however, to ensure the availability of an empty device to service future mount requests, particularly in libraries having only a single gripper mechanism. Thus, even when no mount requests are pending, the status of the peripheral storage devices is continually monitored.