Scheduling transfer of data

1. A method, said method comprising:

in response to a request for a proposed additional data transfer from a source storage system to a target storage system, one or more processors of one or more computers estimating utilization of one or more data transfer components of the source storage system and the target storage system that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on (i) an I/O request rate for the source storage system and the target storage system for recent actual data transfers involving the source storage system and the target storage system combined with (ii) an estimated I/O request rate for the source storage system and the target storage system for the proposed additional data transfer; and

said one or more processors ascertaining whether the estimated utilization exceeds a corresponding utilization threshold, and

if so, said one or more processors postponing execution of the proposed additional data transfer, and

if not, said one or more processors initiating execution of the proposed additional data transfer.

2. The method of claim 1 , said method further comprising:

prior to said estimating utilization, said one or more processors receiving the request for the proposed additional data transfer, and in response, said one or more processors estimating the I/O request rate for the source storage system and the target storage system for the proposed additional data transfer; and

prior to said estimating utilization, said one or more processors determining the I/O request rate for the source storage system and the target storage system for the recent actual data transfers involving the source storage system and the target storage system.

3. The method of claim 1 , wherein said ascertaining ascertains that the estimated utilization does not exceed the corresponding utilization threshold, and in response said one or more processors initiating execution of the proposed additional data transfer.

4. The method of claim 1 , wherein said determines that the estimated utilization exceeds the corresponding utilization threshold, and in response said one or more processors postponing execution of the proposed additional data transfer.

5. The method of claim 4 , said method further comprising:

after said postponing execution of the proposed additional data transfer, said one or more processors subsequently estimating that the utilization of the one or more data transfer components of the source storage system and the target storage system that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on I/O request rates for subsequent actual data transfers from the source storage system to the target storage system and the estimated I/O request rates for the proposed additional data transfer; and

said one or more processors determining whether the subsequent estimated utilization exceeds the corresponding utilization threshold, and if so said one or more processors postponing execution of the proposed additional data transfer, and if not said one or more processors initiating execution of the proposed additional data transfer.

6. The method of claim 1 , said method further comprising:

said one or more processors estimating an average data transfer size for the proposed additional data transfer;

said one or more processors determining an average data transfer size for the recent actual data transfers; and

said one or more processors estimating the utilization of the one or more data transfer components that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on the average data transfer size for the recent actual data transfers and the estimated average data transfer size for the proposed additional data transfer.

7. A computer program product, comprising one or more computer readable hardware storage devices including computer readable program instructions executable by one or more processors of one or more computers to implement a method, said method comprising:

in response to a request for a proposed additional data transfer from a source storage system to a target storage system, said one or more processors estimating utilization of one or more data transfer components of the source storage system and the target storage system that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on (i) an I/O request rate for the source storage system and the target storage system for recent actual data transfers involving the source storage system and the target storage system combined with (ii) an estimated I/O request rate for the source storage system and the target storage system for the proposed additional data transfer; and

said one or more processors ascertaining whether the estimated utilization exceeds a corresponding utilization threshold, and

if so, said one or more processors postponing execution of the proposed additional data transfer, and

if not, said one or more processors initiating execution of the proposed additional data transfer.

8. The computer program product of claim 7 , said method further comprising:

prior to said estimating utilization, said one or more processors receiving the request for the proposed additional data transfer, and in response, said one or more processors estimating the I/O request rate for the source storage system and the target storage system for the proposed additional data transfer; and

prior to said estimating utilization, said one or more processors determining the I/O request rate for the source storage system and the target storage system for the recent actual data transfers involving the source storage system and the target storage system.

9. The computer program product of claim 7 , wherein said ascertaining ascertains that the estimated utilization does not exceed the corresponding utilization threshold, and in response said one or more processors initiating execution of the proposed additional data transfer.

10. The computer program product of claim 7 , wherein said determining determines that the estimated utilization exceeds the corresponding utilization threshold, and in response said one or more processors postponing execution of the proposed additional data transfer.

11. The method of claim 10 , said method further comprising:

after said postponing execution of the proposed additional data transfer, said one or more processors subsequently estimating that the utilization of the one or more data transfer components of the source storage system and the target storage system that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on I/O request rates for subsequent actual data transfers from the source storage system to the target storage system and the estimated I/O request rates for the proposed additional data transfer; and

said one or more processors determining whether the subsequent estimated utilization exceeds the corresponding utilization threshold, and if so said one or more processors postponing execution of the proposed additional data transfer, and if not said one or more processors initiating execution of the proposed additional data transfer.

12. The computer program product of claim 7 , said method further comprising:

said one or more processors estimating an average data transfer size for the proposed additional data transfer;

said one or more processors determining an average data transfer size for the recent actual data transfers; and

said one or more processors estimating the utilization of the one or more data transfer components that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on the average data transfer size for the recent actual data transfers and the estimated average data transfer size for the proposed additional data transfer.

13. A system, comprising one or more computers, wherein the one or more computers include one or more processors and one or more computer readable hardware storage devices including computer readable program instructions executable by the one or more processors to implement a method, said method comprising:

in response to a request for a proposed additional data transfer from a source storage system to a target storage system, said one or more processors estimating utilization of one or more data transfer components of the source storage system and the target storage system that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on (i) an I/O request rate for the source storage system and the target storage system for recent actual data transfers involving the source storage system and the target storage system combined with (ii) an estimated I/O request rate for the source storage system and the target storage system for the proposed additional data transfer; and

said one or more processors ascertaining whether the estimated utilization exceeds a corresponding utilization threshold, and

if so, said one or more processors postponing execution of the proposed additional data transfer, and

if not, said one or more processors initiating execution of the proposed additional data transfer.

14. The system of claim 13 , said method further comprising:

prior to said estimating utilization, said one or more processors receiving the request for the proposed additional data transfer, and in response, said one or more processors estimating the I/O request rate for the source storage system and the target storage system for the proposed additional data transfer; and

prior to said estimating utilization, said one or more processors determining the I/O request rate for the source storage system and the target storage system for the recent actual data transfers involving the source storage system and the target storage system.

15. The system of claim 13 , wherein said ascertaining ascertains that the estimated utilization does not exceed the corresponding utilization threshold, and in response, said one or more processors initiating execution of the proposed additional data transfer.

16. The system of claim 13 , wherein said determining determines that the estimated utilization exceeds the corresponding utilization threshold, and in response, said one or more processors postponing execution of the proposed additional data transfer.

17. The method of claim 16 , said method further comprising:

after said postponing execution of the proposed additional data transfer, said one or more processors subsequently estimating that the utilization of the one or more data transfer components of the source storage system and the target storage system that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on I/O request rates for subsequent actual data transfers from the source storage system to the target storage system and the estimated I/O request rates for the proposed additional data transfer; and

said one or more processors determining whether the subsequent estimated utilization exceeds the corresponding utilization threshold, and if so said one or more processors postponing execution of the proposed additional data transfer, and if not said one or more processors initiating execution of the proposed additional data transfer.

18. The system of claim 13 , said method further comprising:

said one or more processors estimating an average data transfer size for the proposed additional data transfer;

said one or more processors determining an average data transfer size for the recent actual data transfers; and

said one or more processors estimating the utilization of the one or more data transfer components that would occur during the proposed additional data transfer combined with other scheduled data transfers involving the source storage system and the target storage system, based in part on the average data transfer size for the recent actual data transfers and the estimated average data transfer size for the proposed additional data transfer.