DATA MIGRATION WITH WRITE BACK TO SOURCE

• US 20200133556A1
• Filed: 10/31/2018
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: LeCrone, Douglas E., Feeney, Martin, Jones, Jeffrey L.
• Granted Patent: US 10,678,466 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0634 by changing the state or mode of one or more devices
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0671 In-line storage system
• CPC Class Codes: G06F 3/0683 Plurality of storage devices

Abstract

Migrating data from a first storage device to a second storage device includes coupling a host computer to the storage devices, causing the host computer to transition from performing I/O operations with the first storage device to performing I/O operations with the second storage device by modifying metadata used for I/O operations to change a mapping of logical devices to physical devices, migrating data from the first storage device to the second storage device independently of any I/O operations by the host, and acknowledging a data write operation from the host only after the data has been successfully written to both the first storage device and the second storage device. Modifying metadata may include changing control block information in device drivers. The data may be written by the host to the second storage device only and the data may be copied from the second storage device to the first storage device.

Claims

1. A method of migrating data from a first storage device to a second storage device, comprising:

coupling a host computer to the first storage device and the second storage device;

causing the host computer to transition from performing input/output (I/O) operations with the first storage device to performing I/O operations with the second storage device by modifying metadata used for I/O operations to change a mapping of logical devices to physical devices;

migrating data from the first storage device to the second storage device independently of any I/O operations by the host computer; and

acknowledging to the host computer completing of a data write operation by unlocking access to the second storage device only after the data has been successfully written to both the first storage device and the second storage device.

2. A method, according to claim 1, wherein modifying metadata includes changing control block information in device drivers.

3. A method, according to claim 1, wherein the data is written by the host computer to both the first storage device and the second storage device.

4. A method, according to claim 1, wherein the data is written by the host computer to the second storage device only and the data is copied from the second storage device to the first storage device.

5. A method, according to claim 4, wherein other data from a portion of a same area of the first storage device is copied from the first storage device to the second storage device prior to the host computer writing the data to the second storage device.

6. A method, according to claim 5, wherein copying the other data is performed in connection with migrating the data from the first storage device to the second storage device.

7. A method, according to claim 5, wherein copying the other data is performed independently of migrating the data from the first storage device to the second storage device.

8. A method, according to claim 5, wherein the portion is a track.

9. A method, according to claim 5, wherein the portion is locked prior to copying the other data.

10. (canceled)

11. A non-transitory computer readable medium containing software that migrates data from a first storage device to a second storage device that are both coupled to a host computer, the software comprising:

executable code that causes the host computer to transition from performing input/output (I/O) operations with the first storage device to performing I/O operations with the second storage device by modifying metadata used for I/O operations to change a mapping of logical devices to physical devices;

executable code that migrates data from the first storage device to the second storage device independently of any I/O operations by the host computer; and

executable code that acknowledges to the host computer completing of a data write operation by unlocking access to the second storage device only after the data has been successfully written to both the first storage device and the second storage device.

12. A non-transitory computer readable medium, according to claim 11, wherein modifying metadata includes changing control block information in device drivers.

13. A non-transitory computer readable medium, according to claim 11, wherein the data is written by the host computer to both the first storage device and the second storage device.

14. A non-transitory computer readable medium, according to claim 11, wherein the data is written by the host computer to the second storage device only and the data is copied from the second storage device to the first storage device.

15. A non-transitory computer readable medium, according to claim 14, wherein other data from a portion of a same area of the first storage device is copied from the first storage device to the second storage device prior to the host writing the data to the second storage device.

16. A non-transitory computer readable medium, according to claim 15, wherein copying the other data is performed in connection with migrating the data from the first storage device to the second storage device.

17. A non-transitory computer readable medium, according to claim 15, wherein copying the other data is performed independently of migrating the data from the first storage device to the second storage device.

18. A non-transitory computer readable medium, according to claim 15, wherein the portion is a track.

19. A non-transitory computer readable medium, according to claim 15, wherein the portion is locked prior to copying the other data.

20. (canceled)