Distributed storage network for modification of a data object

• US 8,914,707 B2
• Filed: 12/18/2013
• Issued: 12/16/2014
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Resch, Jason K., Cilfone, Bart
• Primary Examiner(s): Merant, Guerrier
• Application Number:
  US14/132,020
• Publication Number:
  US 20140108493A1
• Time in Patent Office: 363 Days
• US Class Current: 714/763
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04N 21/20 Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
• CPC Class Codes: H04N 21/218 Source of audio or video content , e.g. local disk arrays details of retrieval in video databases G06F16/739

Abstract

A distributed storage network generates a plurality of data segments from a data object and stores each of the plurality of data segments as a plurality of encoded data slices generated from an error encoding dispersal function. When the distributed storage network receives a modification request for the data object, it determines a size of the plurality of data segments of the data object from a segment size field and identifies one of the plurality of data segments requiring modification. The identified data segment is reconstructed from the plurality of encoded data slices and modified in accordance with the modification request.

Claims

1. A method, comprises:

processing a modification request to modify a data object, wherein the modification request includes an identification of one or more bytes of a data object for modification;

identifying a portion of the data object that includes the one or more bytes of the data object for modification;

reconstructing the identified portion of the data object from a plurality of encoded data slices to produce a reconstructed portion of the data object; and

modifying the one or more bytes of the data object in the reconstructed portion of the data segment in response to the modification request.

2. The method of claim 1, wherein the portion of the data object includes a plurality of data segments.

3. The method of claim 2, wherein each of the plurality of data segments is stored using an X number of the plurality of encoded data slices.

4. The method of claim 3, wherein each of the plurality of data segments is reconstructed from at least a number T of the X number of the plurality of encoded data slices to produce a plurality of reconstructed data segments of the data object.

5. The method of claim 1, wherein the portion of the data object includes one data segment of the data object, wherein the data segment is stored using the plurality of encoded data slices generated using on an error encoding dispersal function.

6. The method of claim 5, wherein the data segments is reconstructed from at least a number T of the X number of the plurality of encoded data slices to produce a reconstructed data segment of the data object.

7. The method of claim 1, wherein the modification request includes a requested modification to the data object, wherein the requested modification includes at least one of:

an addition, a deletion or revision to one or more bytes of the data object.

8. The method of claim 1, wherein identifying a portion of the data object comprises:

determining a size of the plurality of data segments of the data object from a segment size field; and

identifying one or more of the plurality of data segments requiring modification in response to the position indicator and the size of the plurality of data segments of the data object.

9. The method of claim 1, further comprising:

generating a plurality of rebuilt encoded data slices from the modified reconstructed portion of the data segment using an error encoding dispersal function; and

transmitting the plurality of rebuilt encoded data slices for storage in a plurality of storage units.

10. The method of claim 9, further comprising:

modifying a revision field for the plurality of rebuilt encoded data slices.

11. A device, comprises:

a network interface for interfacing with a plurality of storage units in a storage network; and

at least one processing module operable to;

process a request to modify a data object, wherein the data object is stored as a plurality of data segments;

identify at least one of the plurality of data segments of the data object requiring modification, wherein the at least one identified data segment is stored as a plurality of encoded data slices;

reconstruct the at least one identified data segment from at least a number T of the plurality of encoded data slices to produce at least one reconstructed data segment;

modify the at least one reconstructed data segment based on the request to generate at least one modified data segment.

12. The device of claim 11, wherein the processing module is operable to:

generate a plurality of rebuilt encoded data slices from the at least one modified data segment using an error encoding dispersal function; and

transmit the plurality of rebuilt encoded data slices for storage in the plurality of storage units.

13. The device of claim 12, wherein the request includes a requested modification to the data object and a position indicator that points to one or more bytes of the data object for modification.

14. The device of claim 13, wherein the processing module is operable to:

identify at least one of the plurality of data segments requiring modification in response to the position indicator and size of the plurality of data segments of the data object.

15. A device, comprising:

at least one processing module operable to;

identify a first one of a plurality of data segments of a data object requiring modification in response to a modification request, wherein the first identified one of the plurality of data segments is stored as a first plurality of encoded data slices in one or more storage units;

generate a first replacement data segment based on one or more modifications in the modification request; and

generate a first plurality of replacement encoded data slices from the first replacement data segment based on an error encoding dispersal function; and

transmit the first plurality of replacement encoded data slices to replace the first plurality of encoded data slices of the first identified one of the plurality of data segments in the one or more storage units.

16. The device of claim 15, wherein the at least one processing module is further operable to:

identify a second one of the plurality of data segments of the data object requiring modification in response to the modification request, wherein the second identified one of the plurality of data segments is stored as a second plurality of encoded data slices in one or more storage units;

generate a second replacement data segment based on the one or more modifications in the modification request; and

generate a second plurality of replacement encoded data slices from the second replacement data segment based on the error encoding dispersal function; and

transmit the second plurality of replacement encoded data slices to replace the second plurality of encoded data slices of the second identified one of the plurality of data segments in the one or more storage units.

17. The device of claim 15, wherein the modification request includes a position indicator that indicates one or more bytes of the data object for modification.

18. The device of claim 17, wherein the processing module is operable to identify the first and second one of the plurality of data segments of the data object requiring modification in response to the modification request by:

determining a size of the plurality of data segments of the data object from a segment size field; and

identifying the first and second one of the plurality of data segments requiring modification using the position indicator as including the one or more bytes of the data object for modification.

19. The device of claim 15, wherein the modification request includes a first position indicator that indicates a first one or more bytes of the data object for modification and a second position indicator that indicates a second one or more bytes of the data object for modification.

20. The device of claim 19, wherein the processing module is operable to identify the first and second one of the plurality of data segments of the data object requiring modification in response to the modification request by:

determining a size of the plurality of data segments of the data object from a segment size field;

identifying the first one of the plurality of data segments requiring modification using the first position indicator as including the first one or more bytes of the data object for modification; and

identifying the second one of the plurality of data segments requiring modification using the second position indicator as including the second one or more bytes of the data object for modification.