METHOD AND SYSTEM FOR EFFICIENT SNAPSHOTTING OF DATA-OBJECTS

• US 20110238936A1
• Filed: 03/29/2010
• Published: 09/29/2011
• Est. Priority Date: 03/29/2010
• Status: Abandoned Application

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Inventors: Hayden, Mark G.
• Application Number:
  US12/749,473
• Publication Number:
  US 20110238936A1
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/302 where the computing system component is a software system
• CPC Class Codes: G06F 11/3065 Monitoring arrangements determined by the means or processing involved in reporting the monitored data error or fault reporting or logging G06F11/0766
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity

Abstract

One embodiment of the present invention is directed to a multi-node data-storage system, including a number of component-data-storage-system nodes, which stores data objects, each data object stored as a mirrored portion and an additional portion and a snapshot-operation-triggering mechanism that invokes a snapshot operation on a data object in which mirrored data stored in the mirrored portion of the data object is transformed into data stored in non-mirroring redundant data storage associated with a next snapshot level within the additional portion of the data object. An additional embodiment of the present invention is directed to a multi-node data-storage system in which a snapshot-operation-triggering mechanism automatically invokes a snapshot operation on a data object.

Claims

1. A multi-node data-storage system comprising:

a number of component-data-storage-system nodes that store data objects, each data object stored as a mirrored portion and an additional portion; and

a snapshot-operation-triggering mechanism that invokes a snapshot operation on a data object in which mirrored data stored in the mirrored portion of the data object is transformed into data stored in non-mirroring redundant data storage associated with a next snapshot level within the additional portion of the data object.

2. The multi-node data-storage system of claim 1 wherein the snapshot-operation-triggering mechanism is implemented by computer instructions that execute on one or more nodes of the component-data-storage-system.

3. The multi-node data-storage system of claim 1 wherein the non-mirroring redundant data storage is parity-encoding redundant data storage in which data units that store data and data units that store a computed checksum for the stored data are striped across multiple nodes.

4. The multi-node data-storage system of claim 1 wherein the mirrored portion of a data object is distributed over one of:

a different set of nodes than a set of nodes over which the additional portion of the data object is distributed;

the same set of nodes as the set of nodes over which the additional portion of the data object is distributed; and

a set of nodes that partially overlaps the set of nodes over which the additional portion of the data object is distributed.

5. The multi-node data-storage system of claim 1 wherein data in a first snapshot level associated with a data object is distributed over one of:

a different set of nodes than a set of nodes over which data in a second snapshot associated with a data object is distributed;

the same set of nodes as the set of nodes over which data in a second snapshot associated with a data object is distributed; and

a set of nodes that partially overlaps the set of nodes over which data in a second snapshot associated with a data object is distributed.

6. A multi-node data-storage system comprising:

a number of component-data-storage-system nodes that store data objects, each data object stored as a mirrored portion and an additional portion; and

a snapshot-operation-triggering mechanism that automatically invokes a snapshot operation on a data object in which mirrored data stored in the mirrored portion of the data object is transformed into data redundantly stored in non-mirroring redundant data storage associated with a next snapshot level within the additional portion of the data object.

7. The multi-node data-storage system of claim 6 wherein the snapshot-operation-triggering mechanism is implemented by computer instructions that execute on one or more nodes of the component-data-storage-system.

8. The multi-node data-storage system of claim 6 wherein the snapshot-operation-triggering mechanism periodically operates within the multi-node data-storage system to identify data objects upon which to carry out a snapshot operation.

9. The multi-node data-storage system of claim 6 wherein the automated snapshot-operation-triggering mechanism identifies data objects upon which to carry out a snapshot operation by:

for each data object,

collecting stored data that describes the data object;

based on the collected stored data, evaluating one or more rules; and

when evaluation of a rule indicates that a snapshot operation is to be carried out on the data object, identifying the data object as a data object upon which to carry out a snapshot operation.

10. The multi-node data-storage system of claim 6 wherein the automated snapshot-operation-triggering mechanism identifies data objects upon which to carry out a snapshot operation by:

for each data object,

collecting stored data that describes the data object;

based on the collected stored data, computing a snapshot metric; and

when the computed snapshot metric has a value greater than a threshold value, identifying the data object as a data object upon which to carry out a snapshot operation.

11. The multi-node data-storage system of claim 8 wherein the automated snapshot-operation-triggering mechanism identifies data objects upon which to carry out a snapshot operation based on one or more of:

whether the mirrored portion of the data Object exceeds a threshold size;

whether the data object has been accessed for WRITE operations directed to data units in the mirrored portion of the data object more than a threshold number of times during a preceding time interval;

whether the remaining storage capacity of the multi-node data-storage system has fallen below a threshold capacity; and

whether the computational bandwidth of the multi-node data-storage system has fallen below a threshold bandwidth.

12. The multi-node data-storage system of claim 6 wherein the non-mirroring redundant data storage is parity-encoding redundant data storage in which data units that store data and data units that store a computed checksum for the stored data are striped across multiple nodes.

13. The multi-node data-storage system of claim 6 wherein the mirrored portion of a data object is distributed over one of:

a different set of nodes than a set of nodes over which the additional portion of the data object is distributed;

the same set of nodes as the set of nodes over which the additional portion of the data object is distributed; and

a set of nodes that partially overlaps the set of nodes over which the additional portion of the data object is distributed.

14. The multi-node data-storage system of claim 6 wherein the data in a first snapshot level associated with a data object is distributed over one of

a different set of nodes than a set of nodes over which data in a second snapshot associated with a data object is distributed;

the same set of nodes as the set of nodes over which data in a second snapshot associated with a data object is distributed; and

a set of nodes that partially overlaps the set of nodes over which data in a second snapshot associated with a data object is distributed.

15. A method for efficiently storing data objects in a multi-node data-storage system that includes a number of component-data-storage-system nodes that store data objects, the method comprising:

storing each data object stored as a mirrored portion and an additional portion; and

triggering a snapshot operation on a data object in which mirrored data stored in the mirrored portion of the data object is transformed into data redundantly stored in non-mirroring redundant data storage associated with a next snapshot level within the additional portion of the data object.

16. The method of claim 15 wherein the non-mirroring redundant data storage is parity-encoding redundant data storage in which data units that store data and data units that store a computed checksum for the stored data are striped across multiple nodes.

17. The method of claim 15 wherein a snapshot operation is automatically triggered by an automated snapshot-operation-triggering mechanism implemented by computer instructions that execute on one or more nodes of the component-data-storage-system.

18. The method of claim 17 wherein the snapshot-operation-triggering mechanism periodically operates within the multi-node data-storage system to identify data objects upon which to carry out a snapshot operation.

19. The multi-node data-storage system of claim 17 wherein the automated snapshot-operation-triggering mechanism identifies data objects upon which to carry out a snapshot operation by:

for each data object,

collecting stored data that describes the data object;

based on the collected stored data, evaluating one or more rules; and

when evaluation of a rule indicates that a snapshot operation is to be carried out on the data object, identifying the data object as a data object upon which to carry out a snapshot operation.

20. The multi-node data-storage system of claim 17 wherein the automated snapshot-operation-triggering mechanism identifies data objects upon which to carry out a snapshot operation by:

for each data object,

collecting stored data that describes the data object;

based on the collected stored data, computing a snapshot metric; and

when the computed snapshot metric has a value greater than a threshold value, identifying the data object as a data object upon which to carry out a snapshot operation.