Generic file level restore from a block-level secondary copy

• US 10,089,193 B2
• Filed: 03/15/2017
• Issued: 10/02/2018
• Est. Priority Date: 08/13/2012
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Kumarasamy, Paramasivam, Mitkar, Amit, Erofeev, Andrei, Chedalavada, Durga Prasad, Seshadri, Suma, Devassy, Varghese
• Primary Examiner(s): Coby, Frantz
• Application Number:
  US15/459,979
• Publication Number:
  US 20170249220A1
• Time in Patent Office: 566 Days
• Field of Search: 707639, 707679, 707680, 707681, 707821, 707822, 709213, 711162
• 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. A method for restoring data, comprising:

with a first computing device residing in a data storage system,

using an interface object to obtain file system metadata corresponding to a block-level secondary copy, the block-level secondary copy including a plurality of files stored across a plurality of blocks on one or more secondary storage devices;

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;

in response to a request to restore at least one first file of the plurality of files of the block-level secondary copy, using the interface object to request a read from the one or more secondary storage devices of one or more first blocks of the plurality of blocks, the first blocks corresponding to the first file,

wherein the interface object initiates retrieval of the one or more first blocks from the one or more secondary storage devices, and

wherein the first file is copied, using the one or more first blocks, to one or more primary storage devices associated with the first computing device.

2. The method of claim 1, wherein the interface object comprises one or more of a pseudo device, a device file, and a special file.

3. The method of claim 1, wherein said using the interface object to request the read comprises making a standard system read call.

4. The method of claim 1, wherein a second computing device in communication with the one or more secondary storage devices retrieves the one or more first blocks and forwards the one or more first blocks to the first computing device.

5. The method of claim 1, further comprising generating data for displaying a graphical representation of the secondary copy.

6. The method of claim 1, wherein the file system metadata includes a superblock and said processing comprises processing the superblock.

7. The method of claim 1, further comprising instantiating the interface object on the first computing device.

8. The method of claim 1, wherein a file system driver performs said using the interface object to obtain the file system metadata, performs said processing the obtained file system metadata, and performs said using the interface object to request the read.

9. The method of claim 8, wherein the file system driver corresponds to a first file system type and wherein the file system metadata of the block-level secondary copy is of the first file system type.

10. The method of claim 1, wherein the retrieved one or more first blocks include a data block that corresponds to at least one second file of the 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.

11. The method of claim 10 further comprising, with the first computing device:

determining in conjunction with a request to read the at least one second file that the at least one second file is cached 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 devices.

12. A system, comprising:

a first computing device; and

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

wherein the first computing device is configured to;

use the interface object to obtain file system metadata corresponding to the block-level secondary copy, the block-level secondary copy representing a plurality of files stored across a plurality of blocks on one or more secondary storage devices;

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

in response to a request to restore at least one first file of the plurality of files of the block-level secondary copy, request from the one or more secondary storage devices one or more first blocks of the plurality of blocks, the first blocks corresponding to the first file,

wherein the one or more first blocks are retrieved from secondary storage and copied to primary storage associated with the first computing device.

13. The system of claim 12, wherein the interface object comprises one or more of a pseudo device, a device file, and a special file.

14. The system of claim 12, wherein a media agent module executing on a second computing device and in communication with the one or more secondary storage devices is configured, in response to the request to retrieve the first blocks, to retrieve the first blocks from the one or more secondary storage devices, and to forward the first blocks to the first computing device.

15. The system of claim 12, wherein the first computing device is further configured to generate data for displaying a graphical representation of the secondary copy.

16. The system of claim 12, wherein the file system metadata includes a superblock and the first computing device processes the superblock to mount the block-level secondary copy.

17. The system of claim 13, wherein a file system driver executing on the first computing device is configured to perform the using of the interface object to obtain the file system metadata, to perform the processing of the obtained file system metadata, and to perform the requesting from the one or more secondary storage devices of the one or more first blocks.

18. The system of claim 17, wherein the interface object generates a request to retrieve the one or more first blocks in response to the file system driver making a standard system read call for the at least one first file.

19. The system of claim 17, 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.

20. The system of claim 12 wherein the retrieved one or more first blocks include a data block that corresponds to at least one second file of the mounted secondary copy, and wherein the first computing device is further configured to, subsequent to retrieval of the data block, store the data block in a memory associated with the first computing device.

21. The system of claim 20 wherein the first computing device is further configured to:

determine in conjunction with a request to read the at least one second file that the at least one second file is cached 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.

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

with a first computing device residing in a data storage system,

using an interface object to obtain file system metadata corresponding to a block-level secondary copy, the block-level secondary copy including a plurality of files stored across a plurality of blocks on one or more secondary storage devices;

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;

in response to a request to restore at least one first file of the plurality of files of the block-level secondary copy, using the interface object to request a read from the one or more secondary storage devices of one or more first blocks of the plurality of blocks, the first blocks corresponding to the first file,

wherein the interface object initiates retrieval of the one or more first blocks from the one or more secondary storage devices, and

wherein the first file is copied, using the one or more first blocks, to one or more primary storage devices associated with the first computing device.