Method, apparatus and program storage device for providing asynchronous status messaging in a data storage system

• US 20040243737A1
• Filed: 05/28/2003
• Published: 12/02/2004
• Est. Priority Date: 05/28/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Huynh, Minh-Ngoc Le, Uddin, Kaukab, Micka, William F., Penmetsa, Satish Chandra, Beardsley, Brent C., Schaeffer, Richard A.
• Granted Patent: US 7,290,086 B2
• Time in Patent Office: Days
• US Class Current: 710/22
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: G06F 13/42 Bus transfer protocol, e.g. handshake; Synchronisation
• CPC Class Codes: G06F 2213/0036 Small computer system interface [SCSI]

Abstract

A method, apparatus and program storage device for providing asynchronous status messaging in a data storage system Asynchronous events are returned from a target to an initiator in response to a Read Message from the initiator. The return status message may or may not be associated with a previously given command or Logical Unit (LUN).

Claims

1. A fixed block adapter, comprising:

a host adapter module for transferring information to and from said physical connection; and

a processor, coupled to the host adapter module, the processor being configured to cause the host adapter module to transmit a Read Message to a target for returning asynchronous event information.

2. The fixed block adapter of claim 1 wherein the asynchronous event is not associated with a specific command.

3. The fixed block adapter of claim 1 wherein the Read Message includes a token for identifying a previously issued command.

4. The fixed block adapter of claim 3 wherein the Read Message includes a time-out parameter for setting a time frame for returning event information in response to the Read Message.

5. The fixed block adapter of claim 1 wherein the Read Message includes a time-out parameter for setting a time frame for returning event information in response to the Read Message.

6. The fixed block adapter of claim 1 wherein the host adapter module is configured to receive the returned asynchronous event information.

7. The fixed block adapter of claim 1 further comprising a cluster interconnect interface for coupling to a cluster processor complex, wherein the processor sends a message to the cluster processor complex via the cluster interconnect interface in response to returned event information.

8. The fixed block adapter of claim 1 wherein the processor sends a message to the cluster processor complex via the cluster interconnect interface in response to returned event information.

9. The fixed block adapter of claim 1 wherein the processor is able to abort an outstanding Read Message.

10. The fixed block adapter of claim 1 wherein the processor generates a subsequent Read Message in anticipation of another asynchronous event and completion of an outstanding Read Message.

11. A fixed block adapter, comprising:

a host adapter module for transferring information to and from said physical connection; and

a processor, coupled to the host adapter module, the processor being configured to generate a return message providing asynchronous event information in response to receipt of a Read Message.

12. The fixed block adapter of claim 11 wherein the return message providing asynchronous event information comprises message data indicative of a status for an operation matching a token in the Read Message.

13. The fixed block adapter of claim 11 wherein the return message providing asynchronous event information comprises a No Message indicating no matching operation exits for a token in the Read Message.

14. The fixed block adapter of claim 11 wherein the processor returns the return message to a World Wide Port Name on a World Wide Node Name that is logged in or that is expecting a return message.

15. The fixed block adapter of claim 11 wherein the processor returns the return message to all World Wide Port Name on a World Wide Node Name that are expecting a return message.

16. The fixed block adapter of claim 11 wherein the processor establishes a queue for holding return messages until dispatched, the processor dispatching the return message according to when a return message is queued.

17. The fixed block adapter of claim 16 wherein the processor dispatches messages according to a parallel mode wherein a message is dispatched when a recipient has all necessary resources or according to a sequential mode wherein only a return message is a high priority queue is sent when a predetermined threshold is exceeded at a recipient.

18. The fixed block adapter of claim 16 wherein the queues survive a warmstart.

19. The fixed block adapter of claim 16 wherein the processor requeues a return message when a return message is not transmitted successfully until all paths have been exhausted.

20. The fixed block adapter of claim 16 wherein return messages are assigned a priority when assigned to a buffer.

21. The fixed block adapter of claim 11 wherein the buffer aging is used to clear the queues of return messages meeting an age limitation.

22. The fixed block adapter of claim 11 wherein the return message comprises a volume resource message, a cluster resource message, a warmstart complete notification or a secondary adapter message.

23. A method for providing asynchronous status message, comprising:

sending a Read Message from an initiator to a target;

monitoring command completion at the target;

determining whether return status data is available in response to the Read Message when a command completes;

returning a No Message to the initiator when return status data is not available; and

returning return status data to the initiator when return status data is available.

24. The method of claim 23 further comprising monitoring a time-out parameter provided by the Read Message, and wherein the monitoring command completion at the target further comprises continuing to monitor command completion at the target until the command completes or the time-out parameter expires, a No Message being returned to the initiator when the time-out parameter expires before completion of a command.

25. A storage system, comprising:

a first storage system, the first storage system comprising a first cluster processor complex, a first fixed block adapter and a first storage array;

a first host coupled to the first storage system;

a second storage system, the second storage system comprising a second cluster processor complex, a second fixed block adapter and a second storage array;

a second host coupled to the first storage system; and

an open source path coupling the first and second storage systems;

wherein the first cluster processor complex and first fixed block adapter of the first storage system are configured to provide asynchronous status messaging by transmitting a Read Message to the second fixed block adapter, wherein the Read Message requests return of asynchronous event information from the second storage system.

26. The storage system of claim 25 wherein the asynchronous event is not associated with a specific command.

27. The storage system of claim 25 wherein the Read Message includes a token for identifying a previously issued command.

28. The storage system of claim 27 wherein the Read Message includes a time-out parameter for setting a time frame for returning event information in response to the Read Message.

29. The storage system of claim 25 wherein the Read Message includes a time-out parameter for setting a time frame for returning event information in response to the Read Message.

30. The storage system of claim 25 wherein the second cluster processor complex and second fixed block adapter of the second storage system are configured to generate a return message providing asynchronous event information in response to receipt of a Read Message.

31. The storage system of claim 29 wherein the Read Message is received by the second storage system from the second host.

32. The storage system of claim 29 wherein the Read Message is received by the second storage system from the first storage system.

33. The storage system of claim 29 wherein the return message providing asynchronous event information comprises message data indicative of a status for an operation matching a token in the Read Message.

34. The storage system of claim 29 wherein the return message providing asynchronous event information comprises a No Message indicating no matching operation exits for a token in the Read Message.

35. A storage system, comprising:

a first cluster processor complex;

a first fixed block adapter coupled to the first cluster processor complex; and

a first storage array coupled to the first cluster processor complex;

wherein the first cluster processor complex and first fixed block adapter are configured to provide asynchronous status messaging by transmitting a Read Message to a target storage system, wherein the Read Message requests return of asynchronous event information from the target storage system.

36. A storage system, comprising:

a first cluster processor complex;

a first fixed block adapter coupled to the first cluster processor complex; and

a first storage array coupled to the first cluster processor complex;

wherein the first cluster processor complex and first fixed block adapter are configured to generate a return message providing asynchronous event information to an initiator in response to receiving a Read Message from the initiator.

37. A method for providing asynchronous status messaging between storage systems, comprising:

generating a return status message providing asynchronous event information to an initiator in response to receiving a Read Message from the initiator; and

returning the return message on a completed message command.

38. A method for providing asynchronous status messaging between storage systems, comprising:

generating a Read Message requesting asynchronous status information at an initiator; and

sending the Read Message to a target.

39. A program storage device readable by a computer, the medium tangibly embodying one or more programs of instructions executable by the computer to perform a method for providing asynchronous status messaging, the method comprising:

sending a Read Message from an initiator to a target;

monitoring command completion at the target;

determining whether return status data is available in response to the Read Message when a command completes;

returning a No Message to the initiator when return status data is not available; and

returning return status data to the initiator when return status data is available.

40. The program storage device of claim 39 further comprising monitoring a time-out parameter provided by the Read Message, and wherein the monitoring command completion at the target further comprises continuing to monitor command completion at the target until the command completes or the time-out parameter expires, a No Message being returned to the initiator when the time-out parameter expires before completion of a command.

41. A program storage device readable by a computer, the medium tangibly embodying one or more programs of instructions executable by the computer to perform a method for providing asynchronous status messaging, the method comprising:

generating a return status message providing asynchronous event information to an initiator in response to receiving a Read Message from the initiator; and

returning the return message on a completed message command.

42. A program storage device readable by a computer, the medium tangibly embodying one or more programs of instructions executable by the computer to perform a method for providing asynchronous status messaging, the method comprising:

generating a Read Message requesting asynchronous status information at an initiator; and

sending the Read Message to a target.