Method, system, and program for transferring data between storage devices

• US 6,779,058 B2
• Filed: 07/13/2001
• Issued: 08/17/2004
• Est. Priority Date: 07/13/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kishi, Gregory Tad, Peake, Jonathan Wayne, Norman, Mark Allan, Travis, William Henry
• Primary Examiner(s): Shin, Christopher B.
• Application Number:
  US09/904,976
• Publication Number:
  US 20030014568A1
• Time in Patent Office: 1,131 Days
• Field of Search: 711/112-115, 711/118-123, 711/135-146, 711/151-152, 711/161-169, 707/204, 710/31-35, 710/58-61, 369/47
• US Class Current: 710/60
• CPC Class Codes: G06F 11/1461 Backup scheduling policy
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

Provided is a method, system, and an article of manufacture for maintaining data accessible by a host in two storage devices, wherein the data is comprised of a plurality of data sets. A determination is made of a percentage of uncopied data at the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device. If the calculated percentage is greater than a threshold amount, a rate at which uncopied data sets are transferred from the first storage device to the second storage device is increased.

Claims

1. A method for maintaining data accessible by a host in a first and second storage devices, wherein the data is comprised of a plurality of data sets, comprising:

determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

if the determined percentage is greater than a threshold amount, increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device.

2. The method of claim 1, further comprising:

indicating a data set in the first storage device as uncopied when the data set is modified or newly created.

3. The method of claim 1, wherein the threshold amount is a first threshold amount, further comprising:

if the calculated percentage is greater than a second threshold amount, further increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device.

4. A method for maintaining data accessible by a host in a first and second storage devices, wherein the data is comprised of a plurality of data sets, comprising:

determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

if the determined percentage is greater than a threshold amount, by increasing a priority associated with the uncopied data sets being transferred between the first and second storage devices, wherein the priority is used to determine a rate in which Input/Output requests, including the requests to transfer the uncopied data sets, are processed.

5. The method of claim 4, wherein a controller transfers uncopied data sets from the first storage device to the second storage device, wherein increasing the priority associated with the uncopied data sets being transferred comprises the controller increasing the priority at which the controller transfers uncopied data sets from the first storage device to the second storage device.

6. The method of claim 5, further comprising:

sending a message to the controller in response to detecting that the calculated percentage exceeds the first threshold to increase the priority associated with the uncopied data sets, wherein the controller increases the priority at which uncopied data sets are transferred from the first storage device to the second storage device in response to the message.

7. The method of claim 5, wherein the controller increases the priority associated with uncopied data sets by increasing the priority from a lower priority to a higher priority.

8. The method of claim 7, further comprising:

lowering, with the controller, the priority associated with uncopied data sets from the higher priority to the lower priority when the percentage of uncopied data sets in the first storage device falls below the first threshold.

9. The method of claim 8, further comprising:

sending a message to the controller in response to detecting that the calculated percentage is less than the first threshold to lower the priority associated with the uncopied data sets, wherein the controller lowers the priority at which uncopied data sets are transferred from the first storage device to the second storage device in response to the message.

10. A method for maintaining data accessible by a host in a first and second storage devices, wherein the data is comprised of a plurality of data sets, comprising:

determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

if the determined percentage is greater than a first threshold amount, increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device;

if the calculated percentage is greater than a second threshold amount, lowering a priority at which Input/Output (I/O) requests from a host to the first storage device are processed, wherein the priority is used to determine a rate at which Input/Output requests, including the requests to transfer the uncopied data and host I/O requests, are processed.

11. The method of claim 10, wherein a first controller manages I/O requests to the first storage device, wherein lowering the priority at which I/O requests from the host to the first storage device are processed is performed by the first controller.

12. The method of claim 11, wherein the first controller lowers the priority of host write I/O requests and not host read I/O requests.

13. The method of claim 11, wherein the first controller lowers the priority by delaying processing host I/O requests for a delay time.

14. The method of claim 13, further comprising:

dynamically calculating the delay time that is used to delay processing host I/O requests.

15. The method of claim 14, wherein the delay time is dynamically calculated as a function of the percentage of uncopied data sets in the first storage device.

16. A system for maintaining a plurality of data sets accessible to a host, comprising:

a first and second storage devices including the data sets;

means for determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

means for increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device if the determined percentage is greater than a threshold amount.

17. The system of claim 16, further comprising:

means for indicating a data set in the first storage device as uncopied when the data set is modified or newly created.

18. The system of claim 16, wherein the threshold amount is a first threshold amount, further comprising:

means for increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device if the calculated percentage is greater than a second threshold amount.

19. A system for maintaining a plurality of data sets accessible to a host, comprising:

a first and second storage devices including the data sets;

means for determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

means for increasing a priority associated with the uncopied data sets being transferred between the first and second storage devices if the determined percentage is greater than a threshold amount, wherein the priority is used to determine a rate at which Input/Output requests, including the requests to transfer the uncopied data sets, are processed.

20. The system of claim 19, further comprising:

a controller that transfers uncopied data sets from the first storage device to the second storage device, wherein the means for increasing the priority associated with the uncopied data sets being transferred is implemented by the controller increasing the priority at which the controller transfers uncopied data sets from the first storage device to the second storage device.

21. The system of claim 20, further comprising:

means for sending a message to the controller in response to detecting that the calculated percentage exceeds the first threshold to increase the priority associated with the uncopied data sets, wherein the controller increases the priority at which uncopied data sets are transferred from the first storage device to the second storage device in response to the message.

22. The system of claim 20, wherein the controller increases the priority associated with uncopied data sets by increasing the priority from a lower priority to a higher priority.

23. The system of claim 22, further comprising:

means, performed by the controller, for lowering the priority associated with uncopied data sets from the higher priority to the lower priority when the percentage of uncopied data sets in the first storage device falls below the first threshold.

24. The system of claim 23, further comprising:

means for sending a message to the controller in response to detecting that the calculated percentage is less than the first threshold to lower the priority associated with the uncopied data sets, wherein the means performed by the controller that lowers the priority at which uncopied data sets are transferred from the first storage device to the second storage device lowers the priority in response to the message.

25. A system for maintaining a plurality of data sets accessible to a host, comprising:

a first and second storage devices including the data sets;

means for determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

means for increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device if the determined percentage is greater than a first threshold amount;

means for lowering a priority at which Input/Output (I/O) requests from a host to the first storage device are processed if the calculated percentage is greater than a second threshold amount, wherein the priority is used to determine a rate at which Input/Output requests, including the requests to transfer the uncopied data and host I/O requests, are processed.

26. The system of claim 25, further comprising:

a first controller managing I/O requests to the first storage device, wherein the means for lowering the priority at which I/O requests from the host to the first storage device are processed is performed by the first controller.

27. The system of claim 26, wherein the first controller includes means for lowering the priority of host write I/O requests and not host read I/O requests.

28. The system of claim 26, wherein the means performed by the first controller for lowering the priority by delaying processing host I/O requests for a delay time.

29. The system of claim 28, further comprising:

means for dynamically calculating the delay time that is used to delay processing host I/O requests.

30. The system of claim 29, wherein the delay time is dynamically calculated as a function of the percentage of uncopied data sets in the first storage device.

31. An article of manufacture including code for maintaining data accessible by a host in a first and second storage devices, wherein the data is comprised of a plurality of data sets by:

determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

if the determined percentage is greater than a threshold amount, increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device.

32. The article manufacture of claim 31, further comprising:

indicating a data set in the first storage device as uncopied when the data set is modified or newly created.

33. The article manufacture of claim 31, wherein the threshold amount is a first threshold amount, further comprising:

if the calculated percentage is greater than a second threshold amount, further increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device.

34. An article of manufacture including code for maintaining data accessible by a host in a first and second storage devices, wherein the data is comprised of a plurality of data sets by:

determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

if the determined percentage is greater than a threshold amount, increasing a priority associated with the uncopied data sets being transferred between the first and second storage devices, wherein the priority is used to determine a rate at which Input/Output requests, including the requests to transfer the uncopied data sets, are processed.

35. The article manufacture of claim 34, wherein a controller transfers uncopied data sets from the first storage device to the second storage device, wherein increasing the priority associated with the uncopied data sets being transferred comprises the controller increasing the priority at which the controller transfers uncopied data sets from the first storage device to the second storage device.

36. The article manufacture of claim 35, further comprising:

sending a message to the controller in response to detecting that the calculated percentage exceeds the first threshold to increase the priority associated with the uncopied data sets, wherein the controller increases the priority at which uncopied data sets are transferred from the first storage device to the second storage device in response to the message.

37. The article manufacture of claim 35, wherein the controller increases the priority associated with uncopied data sets by increasing the priority from a lower priority to a higher priority.

38. The article manufacture of claim 37, further comprising:

lowering, with the controller, the priority associated with uncopied data sets from the higher priority to the lower priority when the percentage of uncopied data sets in the first storage device falls below the first threshold.

39. The article manufacture of claim 38, further comprising:

sending a message to the controller in response to detecting that the calculated percentage is less than the first threshold to lower the priority associated with the uncopied data sets, wherein the controller lowers the priority at which uncopied data sets are transferred from the first storage device to the second storage device in response to the message.

40. An article of manufacture including code for maintaining data accessible by a host in a first and second storage devices, wherein the data is comprised of a plurality of data sets by:

determining a percentage of uncopied data in the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device; and

if the determined percentage is greater than a first threshold amount, increasing a rate at which uncopied data sets are transferred from the first storage device to the second storage device;

if the calculated percentage is greater than a second threshold amount, lowering a priority at which Input/Output (I/O) requests from a host to the first storage device are processed, wherein the priority is used to determine a rate at which Input/Output requests, including the requests to transfer the uncopied data and host I/O requests, are processed.

41. The article manufacture of claim 40, wherein a first controller manages I/O requests to the first storage device, wherein lowering the priority at which I/O requests from the host to the first storage device are processed is performed by the first controller.

42. The article manufacture of claim 41, wherein the first controller lowers the priority of host write I/O requests and not host read I/O requests.

43. The article manufacture of claim 41, wherein the first controller lowers the priority by delaying processing host I/O requests for a delay time.

44. The article manufacture of claim 43, further comprising:

dynamically calculating the delay time that is used to delay processing host I/O requests.

45. The article manufacture of claim 44, wherein the delay time is dynamically calculated as a function of the percentage of uncopied data sets in the first storage device.