Data synchronization management

• US 20070022263A1
• Filed: 07/29/2005
• Published: 01/25/2007
• Est. Priority Date: 07/22/2005
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Hess, Randy, Elkington, Susan, Fandel, John
• Granted Patent: US 7,779,218 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/201 between storage system components
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 2201/855 Details of asynchronous mirroring using a journal to transfer not-yet-mirrored changes

Abstract

In one embodiment, a method comprises receiving, in a source controller, a signal indicative of a write request to a source volume managed by the source controller in response to the signal: writing data associated with the write request to a destination controller when a connection to the destination controller is available; and setting a synchronization flag associated with the data storage segment managed by the source controller when a connection to the destination controller is unavailable.

Claims

1. A method, comprising:

receiving, in a source controller, a signal indicative of a write request to a source volume managed by the source controller;

in response to the signal;

writing data associated with the write request to a destination controller when a connection to the destination controller is available; and

setting a synchronization flag associated with the data storage segment managed by the source controller when a connection to the destination controller is unavailable.

2. The method of claim 1, wherein:

the source controller manages a first virtualized memory space;

the write request identifies a segment of the first virtualized memory space; and

the segment of the first virtualized memory space includes a memory location for the flag.

3. The method of claim 1, wherein:

the destination controller manages a second virtualized memory space; and

the second virtualized memory space includes a destination volume that is a replica of the source volume.

4. The method of claim 1, further comprising writing data associated with the write request to a log file managed by the source controller when a connection to the destination controller is unavailable and the log file has capacity for additional data.

5. The method of claim 1, further comprising marking the source volume for a full copy operation when a connection to the destination controller is unavailable and the log file is full.

6. The method of claim 1, further comprising:

initiating a remote copy process to copy contents of the source volume to the destination volume, wherein the remote copy process copies a segment of the source volume only if the synchronization flag associated with the segment is set.

7. The method of claim 1, further comprising:

maintaining a count representative of a number of segments in the source volume for which the synchronization flag is set; and

marking the volume for a full copy when the count exceeds a threshold.

8. An array controller, comprising:

a first I/O port that provides an interface to a host computer;

a second I/O port that provides an interface a storage device;

a processor that receives I/O requests generated by the host computer and, in response to the I/O requests, generates and transmits I/O requests to the storage device; and

a memory module communicatively connected to the processor and comprising logic instructions which, when executed by the processor, configure the processor to;

receive a signal indicative of a write request to a source volume managed by the array controller, and in response to the signal to;

write data associated with the write request to a destination controller when a connection to the destination controller is available; and

set a synchronization flag associated with the data storage segment managed by the array controller when a connection to the destination controller is unavailable.

9. The array controller of claim 8, wherein:

the array controller manages a first virtualized memory space;

the write request identifies a segment of the first virtualized memory space; and

the segment of the first virtualized memory space includes a memory location for the flag.

10. The array controller of claim 8, wherein:

the destination controller manages a second virtualized memory space; and

the second virtualized memory space includes a destination volume that is a replica of the source volume.

11. The array controller of claim 8, further comprising logic instructions which, when executed by the processor, configure the processor to write data associated with the write request to a log file managed by the source controller when a connection to the destination controller is unavailable and the log file has capacity for additional data.

12. The array controller of claim 8, further comprising logic instructions which, when executed by the processor, configure the processor to mark the source volume for a full copy operation when a connection to the destination controller is unavailable and the log file is full.

13. The array controller of claim 8, further comprising logic instructions which, when executed by the processor, configure the processor to initiate a remote copy process to copy contents of the source volume to the destination volume, wherein the remote copy process copies a segment of the source volume only if the synchronization flag associated with the segment is set.

14. The array controller of claim 8, further comprising logic instructions which, when executed by the processor, configure the processor to:

maintain a count representative of a number of segments in the source volume for which the synchronization flag is set; and

mark the volume for a full copy when the count exceeds a threshold.

15. A computer program product comprising logic instructions stored on a computer-readable medium which, when executed by a processor, configure the processor to:

receive a signal indicative of a write request to a source volume managed by an array controller; and

in response to the signal to;

write data associated with the write request to a destination controller when a connection to the destination controller is available; and

set a synchronization flag associated with the data storage segment managed by the array controller when a connection to the destination controller is unavailable.

16. The computer program product of claim 15, wherein:

the array controller manages a first virtualized memory space;

the write request identifies a segment of the first virtualized memory space; and

the segment of the first virtualized memory space includes a memory location for the flag.

17. The computer program product of claim 15, wherein:

the destination controller manages a second virtualized memory space;

the second virtualized memory space includes a destination volume that is a replica of the source volume.

18. The computer program product of claim 15, further comprising logic instructions which, when executed by the processor, configure the processor to write data associated with the write request to a log file managed by the source controller when a connection to the destination controller is unavailable and the log file has capacity for additional data.

19. The computer program product of claim 15, further comprising further comprising logic instructions which, when executed by the processor, configure the processor to mark the source volume for a full copy operation when a connection to the destination controller is unavailable and the log file is full.

20. The computer program product of claim 15, further comprising logic instructions which, when executed by the processor, configure the processor to

initiate a remote copy process to copy contents of the source volume to the destination volume, wherein the remote copy process copies a segment of the source volume only if the synchronization flag associated with the segment is set.

21. The computer program product of claim 15, further comprising logic instructions which, when executed by the processor, configure the processor to:

maintain a count representative of a number of segments in the source volume for which the synchronization flag is set; and

mark the volume for a full copy when the count exceeds a threshold.