Dispersed storage having snapshot clones and methods for use therewith

• US 9,354,980 B2
• Filed: 07/28/2014
• Issued: 05/31/2016
• Est. Priority Date: 01/28/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Baptist, Andrew, Volvovski, Ilya, Leggette, Wesley
• Primary Examiner(s): SCHELL, JOSEPH O
• Application Number:
  US14/444,134
• Publication Number:
  US 20140337686A1
• Time in Patent Office: 673 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1008 in individual solid state devices G06F11/1004 takes precedence
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: G06F 16/184 implemented as replicated file system
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems
• CPC Class Codes: G06F 2201/805 Real-time
• 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
• 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]

Abstract

A directory file includes a plurality of entries, wherein an entry of the plurality of entries includes a file or directory name field, and a snapshot list field that includes a snapshot list. A clone snapshot identifier (ID) is determined for a data file. The directory file is updated to produce an updated directory file, wherein the updating includes updating the snapshot list field associated with the data file to include the clone snapshot ID in the snapshot list.

Claims

1. A method comprises:

obtaining a directory file that includes a plurality of entries, wherein an entry of the plurality of entries includes a file or directory name field, and a snapshot list field that includes a snapshot list;

determining a clone snapshot identifier (ID) regarding a data file;

updating the directory file to produce an updated directory file, wherein the updating includes updating the snapshot list field associated with the data file to include the clone snapshot ID in the snapshot list;

dispersed storage error encoding the updated directory file to produce a set of encoded updated directory file slices; and

sending the set of encoded updated directory file slices to a dispersed storage network (DSN) memory for storage.

2. The method of claim 1, wherein the clone snapshot ID corresponds to a clone snapshot associated with a previous snapshot regarding the data file.

3. The method of claim 2, wherein the clone snapshot includes at least one modification from the previous snapshot.

4. The method of claim 2, wherein the clone snapshot is selectively locked from further changes, or selectively unlocked to allow further changes.

5. The method of claim 1, wherein the snapshot list associates the clone snapshot ID with at least one previous snapshot ID.

6. The method of claim 1 further comprises:

updating a vault snapshot file to associate the clone snapshot ID with at least one previous snapshot ID to produce an updated vault snapshot file that maintains a snapshot history.

7. The method of claim 6, wherein the updated vault snapshot file is associated with a vault of the DSN memory and the updated vault snapshot file maintains a parent-child relationship between the at least one previous snapshot ID and the clone snapshot ID.

8. A dispersed storage and task (DST) processing unit comprises:

at least one module, when operable within a computing device, that causes the computing device to;

obtain a directory file that includes a plurality of entries, wherein an entry of the plurality of entries includes a file or directory name field, and a snapshot list field that includes a snapshot list;

determine a clone snapshot identifier (ID) regarding a data file;

update the directory file to produce an updated directory file, wherein the updating includes updating the snapshot list field associated with the data file to include the clone snapshot ID in the snapshot list;

dispersed storage error encode the updated directory file to produce a set of encoded updated directory file slices; and

send the set of encoded updated directory file slices to a dispersed storage network (DSN) memory for storage.

9. The DST processing unit of claim 8 wherein the clone snapshot ID corresponds to a clone snapshot associated with a previous snapshot regarding the data file.

10. The DST processing unit of claim 9 wherein the clone snapshot includes at least one modification from the previous snapshot.

11. The DST processing unit of claim 8 wherein the clone snapshot is selectively locked from further changes, or selectively unlocked to allow further changes.

12. The DST processing unit of claim 8 wherein the snapshot list associates the clone snapshot ID with at least one previous snapshot ID.

13. The DST processing unit of claim 8 wherein the at least one module, when operable within the computing device, further causes the computing device to:

updating a vault snapshot file to associate the clone snapshot ID with at least one previous snapshot ID to produce an updated vault snapshot file that maintains a snapshot history.

14. The DST processing unit of claim 13 wherein the updated vault snapshot file is associated with a vault of the DSN memory and the updated vault snapshot file maintains a parent-child relationship between the at least one previous snapshot ID and the clone snapshot ID.

15. A non-transitory computer readable storage medium comprises:

at least one memory section that stores operational instructions that, when executed by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), causes the one or more computing devices to;

obtain a directory file that includes a plurality of entries, wherein an entry of the plurality of entries includes a file or directory name field, and a snapshot list field that includes a snapshot list;

determine a clone snapshot identifier (ID) regarding a data file;

update the directory file to produce an updated directory file, wherein the updating includes updating the snapshot list field associated with the data file to include the clone snapshot ID in the snapshot list;

dispersed storage error encode the updated directory file to produce a set of encoded updated directory file slices; and

send the set of encoded updated directory file slices to a dispersed storage network (DSN) memory for storage.

16. The non-transitory computer readable storage medium of claim 15 wherein the clone snapshot ID corresponds to a clone snapshot associated with a previous snapshot regarding the data file.

17. The non-transitory computer readable storage medium of claim 16 wherein the clone snapshot includes at least one modification from the previous snapshot.

18. The non-transitory computer readable storage medium of claim 16 wherein the clone snapshot is selectively locked from further changes, or selectively unlocked to allow further changes.

19. The non-transitory computer readable storage medium of claim 15 wherein the operational instructions, when executed by the one or more processing modules of the one or more computing devices of the dispersed storage network (DSN), further causes the one or more computing devices to:

updating a vault snapshot file to associate the clone snapshot ID with at least one previous snapshot ID to produce an updated vault snapshot file that maintains a snapshot history.

20. The non-transitory computer readable storage medium of claim 19 wherein the updated vault snapshot file is associated with a vault of the DSN memory and the updated vault snapshot file maintains a parent-child relationship between the at least one previous snapshot ID and the clone snapshot ID.