Methods and apparatus for managing a data set stored on a data storage device

• US 6,718,352 B1
• Filed: 03/20/2001
• Issued: 04/06/2004
• Est. Priority Date: 03/20/2001
• Status: Expired due to Term

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Dang, Thai Q., Balcha, Muralidhar R.
• Primary Examiner(s): AMSBURY, WAYNE P
• Application Number:
  US09/812,911
• Time in Patent Office: 1,113 Days
• Field of Search: 707/205, 711/209, 714/6
• US Class Current: 707/611
• CPC Class Codes: G06F 16/184 implemented as replicated file system
• CPC Class Codes: Y10S 707/99956 File allocation

Abstract

The invention is directed to techniques for managing a data set stored on a host computer that is in communication with a data storage assembly. A data manager on a host computer copies the data set to a synchronous copy of the data set stored on the data storage assembly and establishes a synchronous relationship between the data set and the synchronous copy. The data manager of the host computer can split the synchronous copy from the data set and generate a duplicate copy of the synchronous copy. Then the data manager can reestablish the synchronous relationship between the data set stored on the host computer and the synchronous copy stored on the data storage assembly.

Claims

1. In a host computer having a storage device that stores a data set, a method for generating a duplicate copy of the data set on a data storage assembly in communication with the host computer, comprising the steps of:

establishing a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splitting the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copying the synchronous copy of the data set to generate the duplicate copy of the data set;

wherein splitting includes maintaining a record of changed memory locations which change after termination of the synchronous relationship between the data set and the synchronous copy of the data set.

2. The method of claim 1, further comprising the step of re-establishing the synchronous relationship between the data set and the synchronous copy of the data set, after the step of copying the synchronous copy of the data set.

3. The method of claim 1 wherein the record of changed memory locations is a track table indicating modified disk tracks which change after termination of the synchronous relationship and wherein the method further comprises re-establishing the synchronous relationship between the data set and the synchronous copy of the data set, based on the track table, after copying the synchronous copy of the data set.

4. In a host computer having a storage device that stores a data set, a method for generating a duplicate copy of the data set on a data storage assembly in communication with the host computer, comprising the steps of:

establishing a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splitting the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copying the synchronous copy of the data set to generate the duplicate copy of the data set, wherein the step of establishing the synchronous relationship comprises setting up a track table on the data storage assembly that provides status entries for tracks for the synchronous copy of the data set.

5. The method of claim 4, wherein the step of establishing the synchronous relationship comprises setting each status entry in the track table to an invalid status, and, while copying data from the data set to each respective track of the synchronous copy of the data set, setting each status entry for each respective track in the track table to a valid status.

6. The method of claim 4, further comprising the step, in response to an unavailability of the data set, of accessing a specific track in the synchronous copy of the data set to change data in the specific track and setting a respective status entry for the specific track in the track table to indicate a change status for the specific track.

7. In a host computer having a storage device that stores a data set, a method for generating a duplicate copy of the data set on a data storage assembly in communication with the host computer, comprising the steps of:

establishing a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splitting the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copying the synchronous copy of the data set to generate the duplicate copy of the data set, wherein the step of establishing the synchronous relationship comprises setting up a host track table on the host computer that provides status entries for tracks for the data set.

8. The method of claim 7, further comprising the step of copying changed tracks identified by the status entries in the host track table from the data set to the synchronous copy of the data set to re-establish the synchronous relationship between the data set and the synchronous copy of the data set.

9. In a host computer having a storage device that stores a data set, a method for generating a duplicate copy of the data set on a data storage assembly in communication with the host computer, comprising the steps of:

establishing a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splitting the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copying the synchronous copy of the data set to generate the duplicate copy of the data set, wherein the step of splitting the data set from the synchronous copy of the data set comprises the steps of updating the data set based on pending changes to the data set and quiescing the data set.

10. The method of claim 9, wherein the step of updating the data set comprises the step of applying the pending changes maintained in an application queue to the data set.

11. A host computer for generating a duplicate copy of a data set on a data storage assembly in communication with the host computer, the host computer comprising:

a memory that stores a data manager application;

a storage device that stores a data set;

an input/output controller in communication with the memory and the storage device; and

a processor in communication with the memory, the storage device, and the input/output controller, wherein the processor, when operating in accordance with the data manager application, forms a data manager, which;

establishes a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splits the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copies the synchronous copy of the data set to generate the duplicate copy of the data set;

wherein the data manager is operable to split the data set by maintaining a record of changed memory locations which chance after termination of the synchronous relationship between the data set and the synchronous copy of the data set.

12. The host computer of claim 11, wherein the data manager application further configures the processor to re-establish the synchronous relationship between the data set and the synchronous copy of the data set, after copying the synchronous copy of the data set.

13. The host computer of claim 11 wherein the record of changed memory locations is a track table indicating modified disk tracks which change after termination of the synchronous relationship and wherein the method further comprises re-establishing the synchronous relationship between the data set and the synchronous copy of the data set, based on the track table, after copying the synchronous copy of the data set.

14. A host computer for generating a duplicate copy of a data set on a data storage assembly in communication with the host computer, the host computer comprising:

a memory that stores a data manager application;

a storage device that stores a data set;

an input/output controller in communication with the memory and the storage device; and

a processor in communication with the memory, the storage device, and the input/output controller, wherein the processor, when operating in accordance with the data manager application, forms a data manager, which;

establishes a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splits the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copies the synchronous copy of the data set to generate the duplicate copy of the data set,

wherein the data manager application further configures the processor to set up a track table on the data storage assembly that provides status entries for tracks for the synchronous copy of the data set.

15. The host computer of claim 14, wherein the data manager application further configures the processor to set each status entry in the track table to an invalid status, and, while copying data from the data set to each respective track of the synchronous copy of the data set, to set each status entry for each respective track in the track table to a valid status.

16. The host computer of claim 14, wherein the data manager application further configures the processor to access, in response to an unavailability of the data set, a specific track in the synchronous copy of the data set to change data in the specific track and setting a respective status entry for the specific track in the track table to indicate a change status for the specific track.

17. A host computer for generating a duplicate copy of a data set on a data storage assembly in communication with the host computer, the host computer comprising:

a memory that stores a data manager application;

a storage device that stores a data set;

an input/output controller in communication with the memory and the storage device; and

a processor in communication with the memory, the storage device, and the input/output controller, wherein the processor, when operating in accordance with the data manager application, forms a data manager, which;

establishes a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splits the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copies the synchronous copy of the data set to generate the duplicate copy of the data set,

wherein the data manager application further configures the processor to set up a host track table on the host computer that provides status entries for tracks for the data set.

18. The host computer of claim 17, wherein the data manager application further configures the processor to copy changed tracks identified by the status entries in the host track table from the data set to the synchronous copy of the data set to re-establish the synchronous relationship between the data set and the synchronous copy of the data set.

19. A host computer for generating a duplicate copy of a data set on a data storage assembly in communication with the host computer, the host computer comprising:

a memory that stores a data manager application;

a storage device that stores a data set;

an input/output controller in communication with the memory and the storage device; and

a processor in communication with the memory, the storage device, and the input/output controller, wherein the processor, when operating in accordance with the data manager application, forms a data manager, which;

establishes a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splits the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copies the synchronous copy of the data set to generate the duplicate copy of the data set,

wherein the data manager application further configures the processor to update the data set based on pending changes to the data set and to quiesce the data set.

20. The host computer of claim 19, wherein the data manager application further configures the processor to apply the pending changes maintained in an application queue to the data set.

21. In a host computer having a storage device that stores a data set, a method for generating a duplicate copy of the data set on a data storage assembly in communication with the host computer, comprising the steps of:

establishing a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splitting the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set;

copying the synchronous copy of the data set to generate the duplicate copy of the data set; and

recording ongoing data changes in a memory, the memory operable to recall and apply the ongoing data changes to the data set.

22. The method of claim 21 wherein the memory stores a track table operable to hold the ongoing data changes, the track table corresponding to tracks in the data set, the tracks mapping portions of the data set to corresponding portions of the synchronous data set.

23. A host computer for generating a duplicate copy of a data set on a data storage assembly in communication with the host computer, the host computer comprising:

a memory that stores a data manager application;

a storage device that stores a data set;

an input/output controller in communication with the memory and the storage device; and

a processor in communication with the memory, the storage device, and the input/output controller, wherein the processor, when operating in accordance with the data manager application, forms a data manager, which;

establishes a synchronous relationship between the data set and a synchronous copy of the data set, the synchronous copy stored on the data storage assembly;

splits the data set from the synchronous copy of the data set to terminate the synchronous relationship between the data set and the synchronous copy of the data set; and

copies the synchronous copy of the data set to generate the duplicate copy of the data set,

wherein the data manger is further operable to split the data set by recording ongoing data changes in a memory, the memory operable to recall and apply the ongoing data changes to the data set.

24. The host computer of claim 23 wherein the memory stores a track table operative to hold the ongoing data changes, the track table corresponding to tracks in the data set, the tracks mapping portions of the data set to corresponding portions of the synchronous data set.