EFFICIENT CREATION OF MULTIPLE RETENTION PERIOD BASED REPRESENTATIONS OF A DATASET BACKUP

• US 20170277597A1
• Filed: 03/25/2016
• Published: 09/28/2017
• Est. Priority Date: 03/25/2016
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Dillon, Samuel A., Wadhwa, Kshitij, Kushwah, Ajay Pratap Singh, Kyathanahalli, Sumeeth Channaveerappa, Tirupati Nagaraj, Sudhindra Prasad
• Granted Patent: US 11,422,898 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1464 for networked environments

Abstract

A storage tier manager efficiently creates different representations of a dataset backup for different retention periods. Each of the representations of the dataset backup is distinctly identifiable despite initially representing a same dataset backup. The representations are structured metadata corresponding to the dataset backup. One representation is a cached backup version of the dataset backup (“cached backup” or “cached representation”) provided for low latency access while residing at a storage tier of the backup appliance for a relatively short retention period according to a lifecycle management policy. The other representation is a cloud backup version of the dataset backup (“cloud backup” or “cloud representation”) provided for persisting into cloud storage for a longer retention period according to the lifecycle management policy.

Claims

1. A method comprising:

after receiving, by a storage system that deduplicates data, a request to back up a first dataset,

creating, in a first storage tier corresponding to the storage system, a first backup of the first dataset, wherein the first backup corresponds to a first retention period and the first backup comprises first metadata;

copying and modifying, in the first storage tier, the first metadata to create a second backup of the first dataset, wherein the second backup comprises second metadata and the second backup corresponds to a second retention period that is different than the first retention period;

replicating the second backup to a second storage tier; and

removing the first backup from the first storage tier after expiration of the first retention period.

2. The method of claim 1, wherein copying and modifying the first backup to create the second backup comprises copying the first metadata, which includes a first identifier that identifies the first backup, and modifying the copy of the first metadata to include a second identifier instead of the first backup.

3. The method of claim 1, wherein creating the first backup comprises:

creating the first metadata;

creating and maintaining a first mapping structure that indicates locations of data units that constitute the first dataset after deduplication of the first dataset within the first storage tier; and

updating the first metadata to reference the first mapping structure.

4. The method of claim 3 further comprising:

copying the first mapping structure to create a second mapping structure; and

updating the second metadata to reference the second mapping structure.

5. The method of claim 4, wherein replicating the second backup to the second storage tier comprises:

replicating the data units to the second storage tier;

replicating the second mapping structure to the second storage tier; and

replicating the second metadata to the second storage tier.

6. The method of claim 5,

wherein replicating the second mapping structure comprises replicating the second mapping structure with identifiers of objects in the second storage tier that comprise the data units instead of with the locations of the data units in the first storage tier;

wherein replicating the second metadata comprises replicating the second metadata with an identifier of an object that comprises the second mapping structure instead of with the reference to the second mapping structure in the first storage tier.

7. The method of claim 6 further comprising:

prior to replicating the second mapping structure, modifying the second mapping structure to indicate the identifiers of the objects in the second storage tier that comprise the data units instead of the locations of the data units within the first storage tier; and

prior to replicating the second metadata, modifying the second metadata to indicate the identifier of the object that comprises the second mapping structure instead of the reference to the second mapping structure in the first storage tier.

8. The method of claim 1, wherein the first storage tier is a caching storage tier and the second storage tier is a cloud storage tier.

9. One or more non-transitory machine readable media comprising program code for multi-tier data back up with multiple retention periods, the program code to:

after receipt of a request to back up a first dataset,

create, in a first storage tier, a first backup of the first dataset, wherein the first backup corresponds to a first retention period and the first backup comprises first metadata;

copy and modify, in the first storage tier, the first metadata to create a second backup of the first dataset, wherein the second backup comprises second metadata and the second backup corresponds to a second retention period that is different than the first retention period;

replicate the second backup to a second storage tier; and

remove the first backup from the first storage tier after expiration of the first retention period.

10. The one or more non-transitory machine readable media of claim 9, wherein the program code to copy and modify the first backup to create the second backup comprises program code to copy the first metadata, which includes a first identifier that identifies the first backup, and modify the copy of the first metadata to include a second identifier instead of the first backup.

11. The one or more non-transitory machine readable media of claim 9, wherein the program code to create the first backup comprises program code to:

create the first metadata;

create and maintain a first mapping structure that indicates locations of data units that constitute the first dataset after deduplication in the first storage tier; and

update the first metadata to reference the first mapping structure.

12. The one or more non-transitory machine readable media of claim 11 further comprising program code to:

copy the first mapping structure to create a second mapping structure; and

update the second metadata to reference the second mapping structure.

13. The one or more non-transitory machine readable media of claim 12, wherein the program code to replicate the second backup to the second storage tier comprises program code to:

create, in the second storage tier, a set of one or more objects that comprises the data units;

create, in the second storage tier, a first object that comprises the second mapping structure; and

create, in the second storage tier, a second object that comprises the second metadata.

14. The one or more non-transitory machine readable media of claim 13,

wherein the program code to create the first object comprises program code to create the first object with the second mapping structure having a set of one or more identifiers of the set of one or more objects instead of locations of the data units in the first storage tier;

wherein the program code to create the second object comprises program code to create the second object with the second metadata having an identifier of the first object instead of a reference to the second mapping structure in the first storage tier.

15. The one or more non-transitory machine readable media of claim 14 further comprising program code to:

prior to creation of the first object, modify the second mapping structure to indicate the set of one or more identifiers instead of the locations of the data units within the first storage tier; and

prior to creation of the second object, modify the second metadata to indicate the identifier of the first object instead of the reference to the second mapping structure in the first storage tier.

16. A backup appliance comprising:

a processor unit; and

a machine readable medium comprising program code executable by the processor unit to cause the backup appliance to,

after receipt of a request to back up a first dataset,

create, in a first storage tier corresponding to the backup appliance, a first backup of the first dataset, wherein the first backup corresponds to a first retention period and the first backup comprises first metadata;

copy and modify, in the first storage tier, the first metadata to create a second backup of the first dataset, wherein the second backup comprises second metadata and the second backup corresponds to a second retention period that is different than the first retention period;

replicate the second backup to a second storage tier; and

remove the first backup from the first storage tier after expiration of the first retention period.

17. The backup appliance of claim 16, wherein the program code to copy and modify the first backup to create the second backup comprises program code executable by the processor unit to cause the backup appliance to copy the first metadata, which includes a first identifier that identifies the first backup, and modify the copy of the first metadata to include a second identifier instead of the first backup.

18. The backup appliance of claim 16, wherein the program code to create the first backup comprises program code executable by the processor unit to cause the backup appliance to:

create the first metadata;

create and maintain a first mapping structure that indicates locations of data units that constitute the first dataset after deduplication in the first storage tier; and

update the first metadata to reference the first mapping structure.

19. The backup appliance of claim 18, wherein the machine readable medium further comprises program code executable by the processor unit to cause the backup appliance to:

copy the first mapping structure to create a second mapping structure; and

update the second metadata to reference the second mapping structure.

20. The backup appliance of claim 19, wherein the program code to replicate the second backup comprises program code executable by the processor unit to cause the backup appliance to:

create, in the second storage tier, a set of one or more objects that comprises the data units;

create, in the second storage tier, a first object that comprises the second mapping structure with a set of one or more identifiers of the set of one or more objects instead of with the locations of the data units in the first storage tier;

create, in the second storage tier, a second object that comprises the second metadata with an identifier of the first object instead of with the reference to the second mapping structure in the first storage tier.