GENERIC FILE LEVEL RESTORE FROM A BLOCK-LEVEL SECONDARY COPY

• US 20150161015A1
• Filed: 12/10/2014
• Published: 06/11/2015
• Est. Priority Date: 08/13/2012
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: EROFEEV, Andrei, DEVASSY, Varghese, KUMARASAMY, Paramasivam, MITKAR, Amit, CHEDALAVADA, Durga Prasad, SESHADRI, Suma
• Granted Patent: US 9,632,882 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1489 through recovery blocks
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• 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

Systems and methods are provided which perform a file level restore by utilizing existing operating system components (e.g., file system drivers) that are natively installed on the target computing device. These components can be used to mount and/or interpret a secondary copy of the file system. For instance, the system can instantiate an interface object (e.g., a device node such as a pseudo device, device file or special file) on the target client which includes file system metadata corresponding to the backed up version of the file system. The interface provides a mechanism for the operating system to mount the secondary copy and perform file level access on the secondary copy, e.g., to restore one or more selected files.

Claims

1. (canceled)

2. A method for restoring data, comprising:

with a first computing device residing in a data storage system and comprising computer hardware,

interfacing with a device node instantiated on the first computing device to obtain file system metadata corresponding to a block-level secondary copy;

processing the obtained file system metadata with a processor of the first computing device to mount the block-level secondary copy onto the first computing device; and

interfacing with the device node to request a read of at least one file of the secondary copy,

wherein the device node initiates retrieval of the at least one file from secondary storage, and

wherein the retrieved at least one file is copied to primary storage associated with the first computing device.

3. The method of claim 2, wherein the device node comprises one or more of a pseudo device, a device file, or a special file.

4. The method of claim 2, wherein said interfacing with the device node to request a read of the at least one file comprises making a standard system read call.

5. The method of claim 2, wherein a media agent module executing on a second computing device and in communication with the secondary storage retrieves a data block including the at least one file and forwards the data block to the first computing device.

6. The method of claim 2, wherein the file system metadata specifies at least a directory structure for the block-level secondary copy.

7. The method of claim 2, wherein the file system metadata includes a superblock and said processing comprises processing the superblock.

8. The method of claim 2, further comprising instantiating the device node on the first computing device.

9. The method of claim 2, wherein said interfacing with the device node to obtain the file system metadata, said processing the obtained file system metadata, and said interfacing with the device mode to request the read are performed by a file system driver executing on the first computing device.

10. The method of claim 9, wherein the file system driver corresponds to a first file system type and wherein the file system data of the block-level secondary copy is of the first file system type.

11. The method of claim 2, wherein the retrieved at least one file is included in a data block that also includes at least one second file of the mounted secondary copy, the method further comprising, subsequent to retrieval of the data block, storing the data block in a memory associated with the first computing device.

12. The method of claim 11 further comprising, with the first computing device:

interfacing with the device node to request a read of the at least one second file;

determining that the at least one second file resides in the memory associated with the first computing device; and

retrieving the at least one second file from the memory associated with the first computing device,

wherein the retrieved at least one second file is copied to the primary storage.

13. The method of claim 12, wherein the memory associated with the first computing device is a cache memory.

14. A system, comprising:

a first computing device comprising computer hardware;

a device node instantiated as software on the first computing device, the device node providing an interface to access a block-level secondary copy of file system data,

wherein the first computing device is configured to;

interface with the device node to obtain file system metadata corresponding to the block-level secondary copy;

process the obtained file system metadata to mount the block-level secondary copy onto the first computing device; and

request at least one file of the mounted block-level secondary copy from secondary storage,

wherein the at least one file is retrieved from secondary storage and copied to primary storage associated with the first computing device.

15. The system of claim 14, wherein the device node comprises one or more of a pseudo device, a device file, or a special file.

16. The system of claim 14, wherein a media agent module executing on a second computing device and in communication with the secondary storage is configured to, in response to the request to retrieve the at least one file, to retrieve a data block including the at least one file from secondary storage, and to forward the data block to the first computing device.

17. The system of claim 14, wherein the file system metadata specifies at least a directory structure for the block-level secondary copy.

18. The system of claim 14, wherein the file system metadata includes a superblock and the first computing device processes the superblock to mount the block-level secondary copy.

19. The system of claim 14, wherein a file system driver executing on the first computing system is configured to perform the interfacing with the device node, the processing of the obtained file system metadata, and the requesting of the at least one file.

20. The system of claim 19, wherein the device node generates a request to retrieve the at least one file in response to the file system driver making a standard system read call for the at least one file.

21. The system of claim 19, wherein the file system driver corresponds to a first file system type, and wherein the file system data of the block-level secondary copy is of the first file system type.

22. The system of claim 14 wherein the retrieved at least one file is included in a data block that also includes at least one second file of the mounted secondary copy, and wherein the first computing system is further configured to, subsequent to retrieval of the data block, store the data block in a memory associated with the first computing device.

23. The system of claim 22 wherein the first computing device is further configured to:

interface with the device node to request a read of the at least one second file;

determine that the at least one second file resides in the memory associated with the first computing device; and

retrieve the at least one second file from the memory associated with the first computing device,

wherein the retrieved at least one second file is copied to the primary storage.

24. Non-transitory computer storage comprising instructions which, when executed, direct a computer system coupled to the computer storage to perform a method comprising:

interfacing with a device node instantiated on the computer system to obtain file system metadata corresponding to a block-level secondary copy;

processing the obtained file system metadata to mount the block-level secondary copy onto the computer system;

interfacing with the device node to request a read of at least one file of the secondary copy,

wherein the device node initiates retrieval of the at least one file from secondary storage, and

wherein the retrieved at least one file is copied to primary storage associated with the computer system.