Granted Patent B1

US 7,925,630 · App. 11/731,351 · Granted Apr 12, 2011

Assignee: Symantec Corporation

Abstract

Claims (75)

1. A method comprising:

generating a backup image at a secondary system, wherein the backup image comprises a copy of first data received from a primary system;

validating the backup image at the secondary system, wherein the validating continues as second data is received from the primary system;

storing the second data in a memory, if the validating is unfinished, wherein the memory is coupled to the secondary system;

receiving a request for third data from the primary system, wherein the third data corresponds to a timestamp;

determining if the memory comprises the third data;

returning the third data from the memory, if the memory comprises the third data;

accessing a validation table entry corresponding to the timestamp, if the memory does not comprise the third data, wherein

the validation table entry indicates a validation result of an image, the validation result was generated before the receiving the request;

selecting the image, if the validation result indicates a successful validation;

returning the third data from the image, if the validation result indicates a successful validation;

selecting an earlier image, if the validation result indicates a failed validation, wherein

the earlier image is a successfully validated image, and

the earlier image is a most recently validated image generated prior to the timestamp;

returning the third data from the earlier image, if the earlier image is successfully validated; and

wherein the backup image, the image, or the earlier image comprises a point-in-time copy of the third data, and

the memory stores a copy of a version of the third data written to the memory since creation of the point-in-time copy of the third data.

2. The method of claim 1 wherein

the first data comprises final metadata, and

the final metadata indicates whether all metadata is consistent.

3. The method of claim 2 wherein

the first data comprises an indication that all metadata is consistent.

4. The method of claim 1 further comprising validating the image, if the validation result indicates a successful validation; validating the earlier image, if the validation result indicates a failed validation.

5. The method of claim 1 further comprising the returning the third data is in response to the receiving the request.

6. The method of claim 1 wherein the third data comprises an identity of one or more data blocks of the backup image.

7. A computer-readable storage medium comprising instructions executable by a computer system, wherein the computer system implements a method in response to executing the instructions, the method comprising:

generating a backup image at a secondary system, wherein the backup image comprises a copy of first data received from a primary system;

validating the backup image at the secondary system, wherein the validating continues as second data is received from the primary system;

storing the second data in a memory, if the validating is unfinished, wherein the memory is coupled to the secondary system;

receiving a request for third data from the primary system, wherein the third data corresponds to a timestamp;

determining if the memory comprises the third data;

returning the third data from the memory, if the memory comprises the third data;

accessing a validation table entry corresponding to the timestamp, if the memory does not comprise the third data, wherein

the validation table entry indicates a validation result of an image,

the validation result was generated before the receiving the request;

selecting the image, if the validation result indicates a successful validation;

returning the third data from the image, if the validation result indicates a successful validation;

selecting an earlier image, if the validation result indicates a failed validation, wherein

the earlier image is a successfully validated image, and

the earlier image is a most recently validated image generated prior to the timestamp;

returning the third data from the earlier image, if the earlier image is successfully validated; and

wherein

the backup image, the image, or the earlier image comprises a point-in-time copy of the third data, and

the memory stores a copy of a version of the third data written to the memory since creation of the point-in-time copy of the third data.

8. The computer-readable medium of claim 7 wherein

the first data comprises final metadata, and

the final metadata indicates whether all metadata is consistent.

9. The computer-readable medium of claim 8 wherein

the first data comprises an indication that all metadata is consistent.

10. The computer-readable medium of claim 7 wherein the method further comprises

validating the image, if the validation result indicates a successful validation;

validating the earlier image, if the validation result indicates a failed validation.

11. The computer-readable medium of claim 7 wherein the method further comprises

the returning the third data is in response to the receiving the request.

12. The computer-readable medium of claim 7 wherein the third data comprises an identity of one or more data blocks of the backup image.

13. A system comprising:

a primary system for storing a data object;

a secondary system coupled to the primary system for storing a replication of the data object, wherein the computer system comprises a first computer system for processing data of a first image of the replication of the data object;

wherein the secondary system comprises a second computer system, wherein the second computer system comprises a memory that stores instructions executable by the second computer system, wherein the second computer system implements a method if the second computer system executes the instructions, the method comprising:

generating a backup image at a secondary system, wherein the backup image comprises a copy of first data received from a primary system, validating the backup image at the secondary system, wherein

the validating continues as second data is received from the primary system, storing the second data in a memory, if the validating is unfinished, wherein the memory is coupled to the secondary system,

receiving a request for third data from the primary system, wherein the third data corresponds to a timestamp,

determining if the memory comprises the third data,

returning the third data from the memory, if the memory comprises the third data, accessing a validation table entry corresponding to the timestamp, if the memory does not comprise the third data, wherein

the validation table entry indicates a validation result of an image,

the validation result was generated before the receiving the request,

selecting the image, if the validation result indicates a successful validation,

returning the third data from the image, if the validation result indicates a successful validation,

selecting an earlier image, if the validation result indicates a failed validation, wherein

the earlier image is a successfully validated image, and

the earlier image is a most recently validated image generated prior to the timestamp;

returning the third data from the earlier image, if the earlier image is successfully validated; and

wherein

the backup image, the image, or the earlier image comprises a point-in-time copy of the third data, and

the memory stores a copy of a version of the third data written to the memory since creation of the point-in-time copy of the third data.

Assignments (15)