I/O velocity projection for bridge attached channel

• US 20030187627A1
• Filed: 03/29/2002
• Published: 10/02/2003
• Est. Priority Date: 03/29/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Rooney, William J., Yocom, Peter B., Hild, Ulrich
• Granted Patent: US 7,099,814 B2
• Time in Patent Office: Days
• US Class Current: 703/13
• CPC Class Codes: G06F 11/3447 Performance evaluation by modeling
• CPC Class Codes: G06F 11/349 for interfaces, buses
• CPC Class Codes: G06F 13/122 where hardware performs an I/O function other than control of data transfer
• CPC Class Codes: G06F 2201/81 Threshold

Abstract

An impact of configuration changes on controllers is projected, in a computing environment including one or more bridge attached channels. This projection quantifies the impact for each controller affected by the change, such that it is known by a quantifiable value how much the change impacts the controller. In order to project the impact, a projected I/O velocity of the controller is determined. In making the projections, pseudo channels associated with a particular bridge attached channel are modelled as independent channels. Alternatively, a utilization metric of a bridge attached channel is determined and compared to a threshold; pseudo channels associated with the bridge attached channel are modelled as independent channels if the utilization metric is below the threshold.

Claims

1. A method of projecting an impact of configuration changes on controllers in a computing environment having at least one bridge attached channel, said method comprising:

associating a plurality of pseudo-channels with said at least one bridge attached channel,

selecting a first controller associated with a configuration change,

projecting an impact of the configuration change on said first controller, wherein said projecting includes;

modeling said plurality of pseudo-channels as a plurality of independent channels, and

quantifying the impact.

2. The method of claim 1, wherein said modeling comprises designating a second controller as affected by said configuration change if said first controller and said second controller share a common pseudo-channel.

3. The method of claim 2, wherein said first controller and said second controller comprise logical controllers within a single physical controller.

4. The method of claim 1, wherein said modeling comprises designating a second controller as unaffected by said configuration change if said first controller and said second controller utilize different pseudo-channels associated with the same bridge attached channel.

5. The method of claim 1, wherein said projecting comprises determining a projected I/O velocity of said controller, said projected I/O velocity quantifying the impact.

6. The method of claim 5, wherein said determining comprises:

projecting utilization of one or more channels of said controller to obtain one or more channel utilizations;

determining one or more contention factors for said controller, said determining employing said one or more channel utilizations; and

obtaining said projected i/o velocity using at least one contention factor of said one or more contention factors.

7. The method of claim 6, wherein said one or more channels includes at least one pseudo-channel.

8. The method of claim 7, wherein said projecting utilization of one or more channels comprises:

iteratively adjusting projected load on the one or more channels until a projected unassigned load associated with said controller is at a predefined level; and

determining projected utilization of the one or more channels, in response to the iteratively adjusting.

9. A method of projecting an impact of configuration changes on controllers in a computing environment having at least one bridge attached channel, said method comprising:

associating a plurality of pseudo-channels with said at least one bridge attached channel,

determining a utilization metric of said bridge attached channel,

selecting a first controller associated with a configuration change,

projecting an impact of the configuration change on said first controller, wherein said projecting includes;

modeling said plurality of pseudo-channels as a plurality of independent channels if said utilization metric is below a threshold, and

quantifying the impact.

10. The method of claim 9, wherein said utilization metric is channel utilization.

11. The method of claim 10, wherein said threshold is a fixed percent.

12. The method of claim 10, wherein said threshold is pseudo-channel utilization.

13. A system of projecting an impact of configuration changes on controllers in a computing environment having at least one bridge attached channel, said system comprising:

means for associating a plurality of pseudo-channels with said at least one bridge attached channel,

means for selecting a first controller associated with a configuration change,

means for projecting an impact of the configuration change on said first controller, wherein said means for projecting includes;

means for modeling said plurality of pseudo-channels as a plurality of independent channels, and

means for quantifying the impact.

14. The system of claim 13, wherein said means for modeling comprises means for designating a second controller as affected by said configuration change if said first controller and said second controller share a common pseudo-channel.

15. The system of claim 14, wherein said first controller and said second controller comprise logical controllers within a single physical controller.

16. The system of claim 13, wherein said means for modeling comprises means for designating a second controller as unaffected by said configuration change if said first controller and said second controller utilize different pseudo-channels associated with the same bridge attached channel.

17. The system of claim 13, wherein said at least one bridge attached channel is a FICON bridge channel.

18. The system of claim 17, further comprising at least one ESCON channel.

19. The system of claim 17, further comprising at least one dynamic switch.

20. A system of projecting an impact of configuration changes on controllers in a computing environment having at least one bridge attached channel, said system comprising:

means for associating a plurality of pseudo-channels with said at least one bridge attached channel,

means for determining a utilization metric of said bridge attached channel,

means for selecting a first controller associated with a configuration change,

means for projecting an impact of the configuration change on said first controller, wherein said projecting includes;

means for modeling said plurality of pseudo-channels as a plurality of independent channels if said utilization metric is below a threshold, and

means for quantifying the impact.

21. The system of claim 20, wherein said utilization metric is channel utilization.

22. The method of claim 21, wherein said threshold is a fixed percent.

23. The method of claim 21, wherein said threshold is pseudo-channel utilization.

24. At least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform a method of projecting an impact of configuration changes on controllers in a computing environment having at least one bridge attached channel, said method comprising:

associating a plurality of pseudo-channels with said at least one bridge attached channel,

selecting a first controller associated with a configuration change,

projecting an impact of the configuration change on said first controller, wherein said projecting includes;

modeling said plurality of pseudo-channels as a plurality of independent channels, and

quantifying the impact.

25. The at least one program storage device of claim 24, wherein said modeling comprises designating a second controller as affected by said configuration change if said first controller and said second controller share a common pseudo-channel.

26. The at least one program storage device of claim 25, wherein said first controller and said second controller comprise logical controllers within a single physical controller.

27. The at least one program storage device of claim 24, wherein said modeling comprises designating a second controller as unaffected by said configuration change if said first controller and said second controller utilize different pseudo-channels associated with the same bridge attached channel.

28. At least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform a method of projecting an impact of configuration changes on controllers in a computing environment having at least one bridge attached channel, said method comprising:

associating a plurality of pseudo-channels with said at least one bridge attached channel,

determining a utilization metric of said bridge attached channel,

selecting a first controller associated with a configuration change,

projecting an impact of the configuration change on said first controller, wherein said projecting includes;

modeling said plurality of pseudo-channels as a plurality of independent channels if said utilization metric is below a threshold, and

quantifying the impact.

29. The at least one program storage device of claim 28, wherein said utilization metric is channel utilization.

30. The at least one program storage device of claim 29, wherein said threshold is a fixed percent.

31. The at least one program storage device of claim 29, wherein said threshold is pseudo-channel utilization.