A data storage medium library includes a plurality of magazines. The magazines include a plurality of cells. An addressor addresses a logical cell address of the cell that stores a data storage medium. The logical cell address indicates what number the cell is as counted in ascending order in the cells that store data storage media. A reporter reports the logical cell address to a host device. When the addressor counts, the addressor skips an empty cell.

A library partitioning module (LPM) is configured to connect multiple hosts to a tape library. The LPM comprises at least two host input/outputs, each for connection to a respective host; and a library input/output for connection to the library. The LPM is an interface between hosts and a tape library such that it allow several hosts to access the library as if they have sole use of the library's resources. The modification of requests includes intercepting SCSI messages between robot and host and translating/transforming them. At least one tape slot for each host is allocated as a virtual import/export location. When a host sends a command to move a tape between a driver or a tape slot and an import/export location, the request is modified by the LPM so that movement occurs instead between a virtual import/export slot allocated to that host. This avoids conflicts involving the import/export location resources of the library. A handler forming part of the LPM arranges for tapes to be moved between the virtual import/export locations and the actual import/export locations. A library including partitioning and request modifying software is also disclosed.

A system and method for determining media to be exported out of a media library is described. In some examples, the system determines a media component to be exported, determines the media component is in the media library for a specific process, and exports the media component after the process is completed.

According to one embodiment of the present invention, a controller that partitions a media library for multiple host applications can, for each partition, assign a base element address for an element type and associate physical element addresses for elements of an element type with an index value. For a partition, the logical element address corresponding to a physical element address for an element can be determined by adding the index number associated with the physical element address to the base element address for that element type. The physical element address corresponding to a logical element address for an element can be determined by subtracting the base element address for the element type from the logical element address for the element. The result of subtracting the base element address from the logical element address is an index value for which the associated physical element address can be found.

Embodiments of the present invention provide a media library controller that can communicate with multiple physical libraries that are physically separate from each other (i.e., that cannot pass media back and forth). The media library controller can maintain a virtualized aggregate media library representing the physical media libraries with which it is in communication. From the physical media libraries, the media library controller can establish a virtual media library and associate a host with the virtual media library. The virtual media library can represent the portions of a physical media library to which the host is allowed access.