Apparatus, system, and method for communicating control messages between a first device and a second device

• US 20050050169A1
• Filed: 08/25/2003
• Published: 03/03/2005
• Est. Priority Date: 08/25/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Basham, Robert Beverley, Beeston, Ralph Thomas, Dahman, Kirby Grant, Martens, Ronald David, Grunow, Christopher, Grunow, Gerard
• Granted Patent: US 7,409,442 B2
• Time in Patent Office: Days
• US Class Current: 709/219
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0658 Controller construction arrangements
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

An apparatus, system, and method are provided for communicating control messages between a first device and a second device. The apparatus, system, and method include a communication module that directs control messages between a first device and a second device through an intermediate device. The intermediate device is coupled to the first device by a control path and to the second device by a data path. The apparatus, system, and method also include a translation module and a transmission module that cooperate to translate control messages received over the control path at the intermediate device to transport data messages and transport data messages received over the data path at the second device to control messages. Transport data messages are sent over the data path to the second device and control messages from the second device are sent over the control path to the first device.

Claims

1. An apparatus for communicating control messages between a first device and a second device, comprising:

a communication module configured to direct control messages between a first device and a second device through an intermediate device, the intermediate device coupled to the first device by a control path and to the second device by a data path;

a translation module configured to translate control messages received over the control path at the intermediate device to transport data messages and transport data messages received over the data path at the second device to control messages; and

a transmission module configured to send transport data messages over the data path to the second device and control messages from the second device over the control path to the first device.

2. The apparatus of claim 1, further comprising the first device polling a second device for a response control message subsequent to sending a control message to the second device.

3. The apparatus of claim 1, further comprising the intermediate device periodically polling a plurality of second devices coupled to the data path for control messages for the first device.

4. The apparatus of claim 1, further comprising a second device notifying the intermediate device of a control message for the first device and the intermediate device transferring the control message from the second device to the first device in response to a message from the first device.

5. The apparatus of claim 1, wherein the first device and second device are configured to exchange control messages with an intermediate device.

6. The apparatus of claim 1, wherein each transport data message comprises a Small Computer Systems Interface (SCSI) Command Descriptor Block (CDB) that encapsulates a control message.

7. An apparatus for communicating control messages between a media controller and a storage device, comprising:

a media controller configured to direct control messages for a plurality of storage devices over a host control path;

an intermediate device coupled to the host control path and configured to transmit control messages received over the host control path as transport data messages on a data path connecting the intermediate device to the plurality of storage devices and transport data messages received over the data path as control messages on the host control path connecting the intermediate device to the media controller; and

wherein the plurality of storage devices are configured to translate transport data messages received over the data path into control messages and control messages for the media controller into transport data messages for transmission over the data path to the intermediate device.

8. The apparatus of claim 7, wherein the media controller is configured to poll a storage device for a response control message subsequent to sending a control message to the storage device.

9. The apparatus of claim 7, wherein the intermediate device periodically polls the storage devices coupled to the data path for control messages for the media controller.

10. The apparatus of claim 7, wherein a storage device notifies the intermediate device of a control message for the media controller and the intermediate device transfers the control message from the second device to the media controller in response to a message from the media controller.

11. The apparatus of claim 7, wherein each transport data message comprises a Small Computer Systems Interface (SCSI) Command Descriptor Block (CDB) that encapsulates a control message.

12. A system for communicating control messages between a library manager and a storage device over a data path, comprising:

a media library comprising a media library manager configured to automatically mount and unload media cartridges; and

a host configured to communicate over a host control path with the media library manager to access data on a specific media cartridge and to communicate with one or more storage devices over a data path to exchange data, the host further configured to relay control messages between the media library manager and the plurality of storage devices by translating between control messages and transport data messages, the transport data messages traveling over the data path and the control messages traveling over the host control path.

13. The system of claim 12, wherein the media library manager polls the storage devices for a response control message subsequent to sending a control message to the storage device.

14. The system of claim 12, wherein the host periodically polls the storage devices coupled to the data path for control messages for the media library manager.

15. The system of claim 12, wherein a storage device notifies the host of a control message for the media library manager and the host transfers the control message from the storage device to the media library manager in response to a message from the media library manager.

16. The system of claim 12, wherein the media library manager is configured to exchange control messages for storage devices over the host control path instead of a direct communication link to the storage devices.

17. The system of claim 12, wherein the host is configured to function as a storage device controller integrated within the media library and coupled to a plurality of storage devices that have no direct communication link to the media library manager.

18. The system of claim 12, wherein each transport data message comprises a Small Computer Systems Interface (SCSI) Command Descriptor Block (CDB) that encapsulates a control message.

19. A method for communicating control messages between a first device and a second device, comprising:

directing control messages between a first device and a second device through an intermediate device, the intermediate device coupled to the first device by a control path and to the second device by a data path;

the intermediate device translating control messages received over the control path to transport data messages and transport data messages received over the data path to control messages;

sending transport data messages over the data path to the second device and control messages from the second device over the control path to the first device; and

translating transport data messages received by the second device into control messages.

20. The method of claim 19, further comprising the media controller polling a storage device for a response control message subsequent to sending a control message to the storage device.

21. The method of claim 19, further comprising the intermediate device periodically polling storage devices coupled to the data path for control messages for the media controller.

22. The method of claim 19, further comprising:

notifying the intermediate device of a control message for the media controller; and

transferring the control message from the storage device to the media controller in response to a message from the media controller.

23. The method of claim 19, further comprising:

configuring a media controller and a storage device to exchange control messages through an intermediate device.

24. The method of claim 19, wherein each transport data message comprises a Small Computer Systems Interface (SCSI) Command Descriptor Block (CDB) that encapsulates a control message.

25. An apparatus for communicating control messages between a first device and a second device, comprising:

means for directing control messages between a first device and a second device through an intermediate device, the intermediate device coupled to the first device by a control path and the second device by a data path;

means for translating control messages received over the control path to transport data messages and transport data messages received over the data path to control messages;

means for sending transport data messages over the data path to the second device and control messages from the second device over the control path to the first device; and

means for translating transport data messages received by the second device into control messages.

26. The apparatus of claim 25, further comprising means for polling a storage device for a response control message subsequent to sending a control message to the storage device.

27. The apparatus of claim 25, further comprising means for polling storage devices coupled to the data path for control messages for the media controller.

28. An article of manufacture comprising a program storage medium readable by a processor and embodying one or more instructions executable by a processor to perform a method for communicating control messages between a first device and a second device, the method comprising:

directing control messages between a first device and a second device through an intermediate device, the intermediate device coupled to the first device by a control path and the second device by a data path;

translating control messages received over the control path to transport data messages and transport data messages received over the data path to control messages;

sending transport data messages over the data path to the second device and control messages from the second device over the control path to the first device; and

translating transport data messages received by the second device into control messages.

29. The article of manufacture of claim 28, wherein the method further comprises polling a storage device for a response control message subsequent to sending a control message to the storage device.

30. The article of manufacture of claim 28, wherein the method further comprises the intermediate device polling storage devices coupled to the data path for control messages for the media controller.