Abstract: A storage subsystem, method of automatically maintaining the subsystem hardware configuration up to date and program product therefor. The storage subsystem automatically initiates hardware discovery in response to a triggering event. Subsystem hardware information is collected during hardware discovery and checked against a current configuration to identify hardware changes. Whenever hardware changes are identified, the subsystem configures the hardware and calibrates newly configured hardware. So, hardware changes may be automatically discovered, configured and calibrated free from operator intervention.

Abstract: A method for assigning element addresses in an automated data storage library includes determining if a data storage device, such as a tape cartridge, belongs to a particular host's cartridge assignment policy. If so, the data storage device is issued a virtual import/export element address taken from a set of non-common virtual import/export element addresses, if available. If no non-common address is available, then a common virtual import/export element address is assigned to the data storage device. If no addresses, either common or non-common, are available, then the data storage device is queued until an address becomes available.

Abstract: A method for simulating the insertion of a data storage medium into or removal of a data storage medium from an input/output station, alternatively referred to as an import/output station. In one application of the invention, a data storage resides in an I/O station slot. A first variable corresponding to this slot is modified to indicate that the slot is actually empty. A command is issued indicating that the I/O station has been accessed, triggering a scan of the slot by an automated robotic accessor. Since the accessor will detect that the slot is, in fact, full, it will report this status to a library manager which will, in turn, update the first variable. The action of updating this variable is reported to associated devices such as a host computer, host application, or other associated device. In this manner, the operation of the library manager and devices receiving status information may be tested without requiring that a physical data storage medium actually be removed and re-inserted.

Abstract: A method and apparatus is disclosed for managing inventory updates in a data library. The method and apparatus allows mount/demount activity to occur during an inventory update and allows a corresponding increase in the number of data storage media that are available for mount/demount during the inventory update. The invention initiates an inventory update for the data storage media library, scans data storage media in the data storage media library behind opened doors, identifies verified data storage media, receives a request for moving data storage media between the slots and the data storage drives, determines if the request is for verified data storage media and performs the request when the request is determined to be for verified data storage media. The request is requeued when the request is for unverified data storage media.

Abstract: An interlock system is provided for removable-media drive unit to prevent the drive loader from attempting to pull in and mount a data cartridge before it is released by a mechanical gripper or human hand. The interlock system includes a light source and a photodetector positioned in front of the drive on opposite sides of the path cartridge takes when it is being inserted or removed from the drive loader. The presence of the cartridge, gripper or other object in the path interrupts a light beam from the light source thereby signalling the drive controller to disable the drive loader. When the gripper has released the cartridge and withdrawn, or when the path is otherwise clear, the photodetector again detects the light beam and signals the drive controller that the loader can be safely enabled. In one embodiment, the light source and photodetector are mounted on a card which plugs into the face of the drive.

Abstract: Each storage cell in an automated storage and retrieval system is provided with a mark, such as a bar code label, which is detectable to a vision system when the cell is empty. Further, each item storable in a cell is also provided with a mark, such as a bar code label uniquely identifying the item, which is detectable by the vision system. During an inventory of the contents of the system, the vision system is moved across the openings of the cells and scans for the marks. If an item mark is detected, entries in a data table are made indicating the location of the cell being scanned and its occupied status. The identity of the item detected can also be entered into the data table. On the other hand, if a cell mark is detected, entries in a data table are made indicating the location of the cell being scanned and its empty status. If neither mark is detected at a cell, additional steps can be initiated to determine the status of the cell.

Abstract: A method for dispatching work requests in a data storage hierarchy in which directory data is promoted in variable length spans, the use of which are maximized even for work requests entering the work request queue after the span is chosen, is disclosed. A queue of work requests is initially scanned to determine if any requests therein require access to directory data stored in secondary storage within a prescribed proximity of that required by the next request to be dispatched. If such other work requests exist, then directory data in addition to that required by the next request to be dispatched is also promoted. To minimize seek time and rotational latency, the additional data is promoted from secondary storage in a single device I/O cycle. The additional data is chosen by adjusting the outer limits of the span as each work request in queue is scanned. After the actual promotion of the span of data, the existing work request is completed.