Preventing oversubscription to power resources in a computing system

1. A method comprising:

by computer program instructions on a computing device,

identifying from among a plurality of power supplies that are configured to deliver power to a plurality of integrated technology elements (ITEs), and in dependence upon a power redundancy policy, a first number of power supplies usable to supply power to the ITEs and a second number of power supplies usable as a redundant power supply to the ITEs;

detecting that power delivery capabilities of the first number of power supplies of the plurality of power supplies have changed and wherein a second number of functioning power supplies of the second number of power supplies has not changed;

determining, in dependence upon the power redundancy policy and the changed power delivery capabilities of the first number of power supplies usable to supply power to the ITEs, power settings for the plurality of ITEs by identifying maximum amount of power that can be consumed by each of the ITEs without violating the power redundancy policy; and

updating, by the power management module, power settings for the plurality of ITEs.

2. The method of claim 1 where the method further comprises:

determining, in dependence upon the power delivery capabilities of the first number of functioning power supplies of the first number of power supplies and not upon the redundant power supplies of the second number of power supplies, updated power settings for the plurality of ITEs.

3. The method of claim 1 wherein determining power settings for the one or more ITEs further comprises determining power settings for the plurality of ITEs in dependence upon a number of functioning power supplies.

4. The method of claim 1 wherein updating power settings for the plurality of ITEs further comprises transmitting, to each ITE, a throttle power level identifying the amount of power that the ITE may consume when throttled.

5. The method of claim 1 wherein updating power settings for the plurality of ITEs further comprises transmitting, to each ITE, a throttle control value indicating whether the ITE must throttle power consumption upon an occurrence of a power supply failure.

6. The method of claim 1 wherein detecting that power delivery capabilities of the power supplies have changed further comprises detecting that a failed power supply has recovered.

7. The method of claim 1 , wherein determining the power settings for the plurality of ITEs further includes, in response to determining the second number of power supplies usable as the redundant power supply to the ITEs violates the redundancy policy, reducing the first number of power supplies usable to supply power to the ITEs.

8. The method of claim 1 , wherein determining the power settings for the plurality of ITEs further includes:

designating a sufficient number of power supplies as usable to supply power to the ITEs; and

designating an additional number of power supplies as usable as the redundant power supply to the ITEs such that the power redundancy policy is not violated.

9. An apparatus comprising a computer processor and a computer memory operatively coupled to the computer processor, the computer memory having disposed within it computer program instructions that, when executed by the computer processor, cause the apparatus to carry out the steps of:

identifying from among a plurality of power supplies that are configured to deliver power to a plurality of integrated technology elements (ITEs), and in dependence upon a power redundancy policy, a first number of power supplies usable to supply power to the ITEs and a second number of power supplies usable as a redundant power supply to the ITEs;

detecting that power delivery capabilities of the first number of power supplies of the plurality of power supplies have changed and wherein a second number of functioning power supplies of the second number of power supplies has not changed;

determining, in dependence upon the power redundancy policy and the changed power delivery capabilities of the first number of power supplies usable to supply power to the ITEs, power settings for the plurality of ITEs by identifying maximum amount of power that can be consumed by each of the ITEs without violating the power redundancy policy; and

updating, by the power management module, power settings for the plurality of ITEs.

10. The apparatus of claim 9 wherein detecting that power delivery capabilities of the power supplies have changed further comprises detecting that a number of functioning power supplies has changed.

11. The apparatus of claim 9 wherein determining power settings for the one or more ITEs further comprises determining power settings for the plurality of ITEs in dependence upon a number of functioning power supplies.

12. The apparatus of claim 9 wherein updating power settings for the plurality of ITEs further comprises transmitting, to each ITE, a throttle power level identifying the amount of power that the ITE may consume when throttled.

13. The apparatus of claim 9 wherein updating power settings for the plurality of ITEs further comprises transmitting, to each ITE, a throttle control value indicating whether the ITE must throttle power consumption upon an occurrence of a power supply failure.

14. The apparatus of claim 9 wherein detecting that power delivery capabilities of the power supplies have changed further comprises detecting that a failed power supply has recovered.

15. A computer program product including a non-transitory computer readable medium, the computer program product comprising computer program instructions that, when executed, cause a computer to carry out the steps of:

identifying from among a plurality of power supplies that are configured to deliver power to a plurality of integrated technology elements (ITEs), and in dependence upon a power redundancy policy, a first number of power supplies usable to supply power to the ITEs and a second number of power supplies usable as a redundant power supply to the ITEs;

detecting that power delivery capabilities of the first number of power supplies of the plurality of power supplies have changed and wherein a second number of functioning power supplies of the second number of power supplies has not changed;

determining, in dependence upon the power redundancy policy and the changed power delivery capabilities of the first number of power supplies usable to supply power to the ITEs, power settings for the plurality of ITEs by identifying maximum amount of power that can be consumed by each of the ITEs without violating the power redundancy policy; and

updating, by the power management module, power settings for the plurality of ITEs.

16. The computer program product of claim 15 wherein detecting that power delivery capabilities of the power supplies have changed further comprises detecting that a number of functioning power supplies has changed.

17. The computer program product of claim 15 wherein determining power settings for the one or more ITEs further comprises determining power settings for the plurality of ITEs in dependence upon a number of functioning power supplies.

18. The computer program product of claim 15 wherein updating power settings for the plurality of ITEs further comprises transmitting, to each ITE, a throttle power level identifying the amount of power that the ITE may consume when throttled.

19. The computer program product of claim 15 wherein updating power settings for the plurality of ITEs further comprises transmitting, to each ITE, a throttle control value indicating whether the ITE must throttle power consumption upon an occurrence of a power supply failure.

20. The computer program product of claim 15 wherein detecting that power delivery capabilities of the power supplies have changed further comprises detecting that a failed power supply has recovered.