PROCESSING OF DATA TO PERFORM SYSTEM CHANGES IN AN INPUT/OUTPUT PROCESSING SYSTEM

• US 20090210561A1
• Filed: 02/14/2008
• Published: 08/20/2009
• Est. Priority Date: 02/14/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Craig, Matthew R., Kalos, Matthew J., Yudenfriend, Harry M., Huang, Catherine C., Flanagan, John R., Ricci, Louis W., Carlson, Scott M., Bendyk, Mark P., Hathorn, Roger G., Sittmann, Gustav E., Casper, Daniel F., Holley, Bret W.
• Granted Patent: US 8,214,562 B2
• Time in Patent Office: Days
• US Class Current: 710/5
• CPC Class Codes: G06F 13/122 where hardware performs an I/O function other than control of data transfer

Abstract

A computer program product, an apparatus, and a method for processing communications between a target and an initiator an input/output processing system are provided. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes: sending a message from the initiator to the target, the message requesting suspension of input/output operations between the initiator and the target for a period of time, the period of time being defined by the message; responsive to the message, suspending input/output operation messages for the period of time; performing a system change comprising at least one of: at least one update, a computer program installation, a recovery, and a change in operating parameters; and initiating new input/output operations after at least one of: expiration of the period of time and initiation of new input/output operations by the initiator.

Claims

1. A computer program product for processing communications between an initiator and a target in an input/output processing system, comprising a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:

the target receiving a message from the initiator, the message requesting suspension of input/output operations between the initiator and the target for a period of time, the period of time being defined by the message;

responsive to the message, suspending input/output operation messages for the period of time;

performing a system change comprising at least one of;

at least one update, a computer program installation, a recovery, and a change in operating parameters; and

initiating new input/output operations after at least one of;

expiration of the period of time and initiation of new input/output operations by the initiator.

2. The computer program product of claim 1, wherein the computer program installation is a firmware installation performed by a host computer system.

3. The computer program product of claim 1, wherein the change in operating parameters comprises a change between a first operating mode and a second operating mode of at least one of the channel and the control unit.

4. The computer program product of claim 3, wherein the first operating mode uses a first protocol supporting Channel Command Words (CCW), and the second operating mode uses a second protocol supporting Transport Control Words (TCW).

5. The computer program product of claim 1, wherein the at least one update is at least one of a code update and a code reload.

6. The computer program product of claim 1, wherein one of the target and the initiator is a channel subsystem of a host computer system, and another of the target and the initiator is a control unit capable of commanding and determining a status of an I/O device.

7. The computer program product of claim 6, wherein the recovery is a control unit recovery.

8. The computer program product of claim 1, wherein the message is a Process Log-out (PRLO) message.

9. The computer program product of claim 8, wherein the initiator, prior to sending the PRLO message, performs at least one of:

sending at least one busy signal to the channel subsystem in response to at least one request for execution of an input/output operation, completing pending input/output operations, and terminating pending input/output operations.

10. The computer program product of claim 8, further comprising initiating a Process Log-in (PRLI) message after performing the system change.

11. The computer program product of claim 10, wherein initiating the PRLI message comprises:

sending an identification message from the target to the initiator to determine whether the initiator supports a PRLI/PRLO protocol; and

responsive to receiving an identification message response indicating that the initiator supports the PRLI/PRLO protocol, sending the PRLI message to the initiator.

17. The apparatus of claim 1, further comprising initiating a Process Log-in (PRLO) message to establish the system change.

12. An apparatus for processing communications in an input/output processing system, comprising:

a target, and an initiator in communication with the target, the apparatus performing;

the target receiving a message from the initiator, the message requesting suspension of input/output operations between the initiator and the target for a period of time, the period of time being defined by the message;

responsive to the message, suspending input/output operation messages for the period of time;

performing a system change comprising at least one of;

at least one update, a computer program installation, a recovery, and a change in operating parameters; and

initiating new input/output operations after at least one of;

expiration of the period of time and initiation of new input/output operations by the initiator.

13. The apparatus of claim 12, wherein the computer program installation is a firmware installation performed by a host computer system.

14. The apparatus of claim 12, wherein the change in operating parameters comprises a change between a first operating mode and a second operating mode of at least one of the channel and the control unit.

15. The apparatus of claim 12, wherein one of the target and the initiator is a channel subsystem of a host computer system, and another of the target and the initiator is a control unit capable of commanding and determining a status of an I/O device.

16. The apparatus of claim 12, wherein the message is a Process Log-out (PRLO) message.

18. A method of processing communications between an initiator and a target in an input/output processing system, the method comprising:

the target receiving a message from the initiator, the message requesting suspension of input/output operations between the initiator and the target for a period of time, the period of time being defined by the message;

responsive to the message, suspending input/output operation messages for the period of time;

performing a system change comprising at least one of;

at least one update, a computer program installation, a recovery, and a change in operating parameters; and

initiating new input/output operations after one of;

expiration of the period of time and initiation of new input/output operations by the initiator.

19. The method of claim 18, wherein one of the target and the initiator is a channel subsystem of a host computer system, and another of the target and the initiator is a control unit capable of commanding and determining a status of an I/O device.

20. The method of claim 18, wherein the message is a Process Log-out (PRLO) message.