MULTIPLE RETENTION PERIOD BASED REPRESENTATONS OF A DATASET BACKUP

• US 20170277596A1
• 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: Kyathanahalli, Sumeeth Channaveerappa, Dillon, Samuel A., Kushwah, Ajay Pratap Singh, Tirupati Nagaraj, Sudhindra Prasad, Wadhwa, Kshitij
• Granted Patent: US 10,489,345 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 16/125 characterised by the use of retention policies retention policies for HSM systems G06F16/185
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor

Abstract

A storage tier manager 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 at a first storage tier corresponding to the deduplicated storage system a first representation of the first dataset backup, wherein the first representation corresponds to a first retention period and the first representation references a plurality of data units that constitute the first dataset;

creating at the first storage tier a second representation of the first dataset backup, wherein the second representation corresponds to a second retention period that is longer than the first retention period and references the plurality of data units that constitute the first dataset;

replicating the second representation of the first dataset backup and the plurality of data units to a second storage tier from the first storage tier;

after detecting expiration of the first retention period,

removing from the first storage tier those of the plurality of data units that are not referenced by a representation of another dataset backup; and

removing the first representation of the first dataset backup from the first storage tier.

2. The method of claim 1, wherein the first representation comprises metadata about the first dataset and location information of the plurality of data units that constitutes the first data set and the second representation comprises metadata about the first dataset and location information of the plurality of data units.

3. The method of claim 1, wherein creating the second representation comprises copying the first representation.

4. The method of claim 1, wherein creating the first representation comprises creating the first representation with an indication of a first type of representation and creating the second representation comprises creating the second representation with an indication of a second type of representation, wherein the first and second types are different.

5. The method of claim 4, wherein the first type corresponds to a first storage tier and the second type corresponds to a second storage tier.

6. The method of claim 1 further comprising removing the second representation from the first storage tier after the second representation and the plurality of data units have been replicated to the second storage tier.

7. The method of claim 1, wherein a backup application communicates the request to back up the first dataset.

8. The method of claim 7 further comprising notifying the backup application that the second representation and the plurality of data units have successfully replicated to the second storage tier.

9. The method of claim 1 further comprising receiving a communication that the first retention period has expired for the first representation.

10. 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.

11. 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:

create a plurality of representations of a dataset backup in a first storage tier for a plurality of retention periods associated with the dataset backup,

wherein each of the plurality of representations comprises metadata about the dataset backup and references to a plurality of data units that constitute the dataset backup,

wherein a first representation of the plurality of representations corresponds to the first storage tier and a first retention period of the plurality of retention periods;

replicate the plurality of data units and a second representation of the plurality of representations to a second storage tier, wherein the second storage tier corresponds to a second retention period of the plurality of retention periods; and

recover storage space occupied by those of the plurality of data units that are not referenced by a representation of another dataset backup at the first storage tier, after expiration of the first retention period.

12. The one or more non-transitory machine readable media of claim 11, wherein the program code to replicate comprises program code to:

create a first set of one or more objects in the second storage tier for the plurality of data units, wherein the second storage tier implements object storage; and

create, in the second storage tier, an object for the second representation with references to the first set of one or more objects instead of references to the plurality of data units in the first storage tier.

13. The one or more non-transitory machine readable media of claim 11, wherein the program code to create the object for the second representation with references to the first set of one or more objects instead of references to the plurality of data units in the first storage tier comprises program code to create the object for the second representation to include a set of one or more object keys that identify the set of one or more object for the plurality of data units.

14. The one or more non-transitory machine readable media of claim 11, wherein the program code to create the plurality of representations comprises program code to create the first representation with an indication of a first type of representation and create the second representation with an indication of a second type of representation, wherein the first type corresponds to the first storage tier and the second type corresponds to the second storage tier.

15. The one or more non-transitory machine readable media of claim 11, wherein the first storage tier corresponds to a caching storage and the second storage tier corresponds to a cloud storage tier.

16. The one or more non-transitory machine readable media of claim 11, wherein the program code to create the plurality of representations comprises the program code to create the plurality of representations after receipt of a request from a backup application to back up a dataset.

17. A deduplicated storage system comprising:

a processor unit; and

a machine readable medium comprising program code executable by the processor unit to cause the deduplicated storage system to,

create a plurality of representations of a dataset backup in a first storage tier for a plurality of retention periods associated with the dataset backup,

wherein each of the plurality of representations comprises metadata about the dataset backup and references to a plurality of data units that constitute the dataset backup,

wherein a first representation of the plurality of representations corresponds to the first storage tier and a first retention period of the plurality of retention periods,

wherein the first storage tier corresponds to the deduplicated storage system;

replicate the plurality of data units and a second representation of the plurality of representations to a second storage tier, wherein the second storage tier corresponds to a second retention period of the plurality of retention periods; and

recover storage space occupied by those of the plurality of data units that are not referenced by a representation of another dataset backup at the first storage tier, after expiration of the first retention period.

18. The deduplicated storage system of claim 17, wherein the program code to replicate comprises program code executable by the processor unit to cause the deduplicated storage system to:

create a first set of one or more objects in the second storage tier for the plurality of data units, wherein the second storage tier implements object storage; and

create, in the second storage tier, an object for the second representation with references to the first set of one or more objects instead of references to the plurality of data units in the first storage tier.

19. The deduplicated storage system of claim 17, wherein the program code to create the object for the second representation with references to the first set of one or more objects instead of references to the plurality of data units in the first storage tier comprises program code executable by the processor unit to cause the deduplicated storage system to create the object for the second representation to include a set of one or more object keys that identify the set of one or more object for the plurality of data units.

20. The deduplicated storage system of claim 17, further comprising a plurality of storage devices that constitute the first storage tier.