Virtual disk from network shares and file servers

• US 9,087,066 B2
• Filed: 04/23/2010
• Issued: 07/21/2015
• Est. Priority Date: 04/24/2009
• Status: Active Grant

• Current Assignee: Swish Data Corp.
• Original Assignee: Swish Data Corp.
• Inventors: Acharya, Soubir
• Primary Examiner(s): Cao, Phuong Thao
• Application Number:
  US12/766,778
• Publication Number:
  US 20100274784A1
• Time in Patent Office: 1,915 Days
• Field of Search: 707/736, 707/812, 707/825, 707/809, 707/E17.01, 707/E17.032, 707/E17.095, 707/E17.143
• US Class Current: 1/1
• CPC Class Codes: G06F 16/164 File meta data generation

Abstract

A system manages a file directory containing data that is exposed by a file-server. The system provides a block-device layered on top of a network share that treats the underlying network share as read-only but allows local file-system semantics to operate on top of the network share. The end-result is a virtual disk containing a locally recognizable file-system that can read and write from the perspective of the operating system but where the data is store in the cloud as network shares. The virtual disk appears to be a fully functional local disk with all the expected local disk semantics.

Claims

1. A method for providing a virtual disk, the method comprising:

providing a computer system including a processor that executes an operating system, wherein the computer system is in communication with a network share that stores data;

the processor creating a disk layer interface that interfaces between the operating system and the virtual disk;

the processor determining which file system interacts with the operating system;

based on the determined file system, the processor creating metadata for the operating system to access file data stored in the virtual disk, wherein the metadata provides information to the determined file system for retrieving file data from and writing file data to the virtual disk;

the processor creating a network interface to communicate between the disk layer interface and the network share; and

the processor exposing the virtual disk, through the disk layer interface, to the operating system, wherein the virtual disk appears as a local disk to the operating system and wherein the file data is stored in the network share;

the disk layer interface communicating with the operating system;

the disk layer interface intercepting a read request directed to the virtual disk for a file;

the disk layer interface returning file data associated with the file in response to the read request;

the network interface receiving the read request;

the network interface determining the network share that stores block data associated with the file;

the network interface communicating with the network share to read the block data from the network share; and

the network interface returning the block data to the disk layer interface to be returned as the file data.

2. The method as defined in claim 1, wherein the file system is one of EXT3 or NTFS.

3. The method as defined in claim 1, wherein the metadata comprises file system metadata and file metadata.

4. The method as defined in claim 3, wherein the file system metadata provides metadata for the file system to interface with the virtual disk.

5. The method as defined in claim 3, wherein the file metadata provides a wrapper for the file data, wherein the wrapper exposes the file data as stored on a local disk, and wherein the wrapper provides a pointer to the network share to retrieve the file data.

6. The method as defined in claim 1, wherein the network share is stored in cloud storage, and the method further comprising transforming a directory structure in the cloud to a directory hierarchy for the file system.

7. The method as defined in claim 1, further comprising:

the processor receiving a read request for data stored on the virtual disk;

the processor triggering a virtual file system layer;

the processor accessing the network share via a pointer stored in the metadata;

the processor reading block data stored in the network share; and

the processor returning the block data as file data.

8. The method as defined in claim 1, further comprising:

the processor receiving new file data to be stored in the virtual disk;

the processor placing the new file data in a local file system cache;

the processor creating metadata for the new file data; and

the processor writing the new file data to the network share.

9. A non-transitory computer readable medium having stored thereon instructions that cause a computing system to execute a method for interacting with a virtual disk, the instructions comprising:

instructions to receive a read request, for data associated with a file stored on the virtual disk created on the computing system, from an operating system;

instructions to trigger a virtual file system layer, wherein the virtual file system layer exposes the virtual disk to the operating system as a local disk;

instructions to execute a disk layer interface on the computing system, wherein the disk layer interface is configured to;

read metadata associated with the file to access pointers to the file;

pass the pointers to a network interface;

return file data to the operating system;

instructions to execute the network interface on the computing system, wherein the network interface is configured to;

access the network share via a pointer stored in the metadata;

read the block data stored in the network share;

assemble the block data into file data; and

return the file data to the disk layer interface.

10. The non-transitory computer readable medium as defined in claim 9, wherein the metadata comprises file system metadata and file metadata.

11. The non-transitory computer readable medium as defined in claim 10, wherein the file metadata provides a wrapper for the file data, wherein the wrapper exposes the file data to the operating system as a file stored on a local disk, and wherein the wrapper provides the pointer to the network share to retrieve the block data.

12. The non-transitory computer readable medium as defined in claim 10, wherein the file system metadata provides metadata for the operating system to interface with the virtual disk.

13. The non-transitory computer readable medium as defined in claim 9, wherein the metadata is stored in a virtual master file table.

14. The non-transitory computer readable medium as defined in claim 9, further comprising:

instructions to receive new file data to be stored in the virtual disk;

instructions to place the new file data in a local file system cache;

instructions to create new metadata for the new file data; and

instructions to write the new file data to the network share.

15. A server, comprising:

a hardware processor, the hardware processor configured to execute;

an operating system;

a virtual disk, wherein the virtual disk is exposed to the operating system as a local disk, and wherein the virtual disk is configured to store data in a network share; and

a virtualization module in communication with the operating system and the virtual disk, the virtualization module configured to expose the virtual disk to the operating system as a local disk, wherein the virtualization module comprises;

a disk layer interface configured to;

communicate with the operating system;

intercept a read request directed to the virtual disk for a file;

return file data associated with the file in response to the read request;

a network interface in communication with the disk layer interface, the network interface configured to;

receive the read request;

determine the network share that stores block data associated with the file;

communicate with the network share to read the block data from the network share; and

return the block data to the disk layer interface to be returned as the file data.

16. The server as defined in claim 15, wherein the virtualization module comprises a metadata engine configured to:

create file system metadata read by the disk layer interface to expose the virtual disk as a local disk;

create file metadata read by the network interface to determine the network share that stores block data associated with the file.

17. The server as defined in claim 16, wherein the metadata engine is configured to store the file system metadata and the file metadata in a virtual master file table.

18. The server as defined in claim 17, wherein the virtual master file table comprises:

the file system metadata that comprises;

MFT data;

Secure data;

BITMAP data;

the file metadata that comprises;

a file name;

a pointer to a network share where the block data is stored;

directory structure information; and

permissions information.

19. The server as defined in claim 16, further comprising a directory organization module configured to:

determine a directory structure of the block data stored in the network share; and

provide metadata to the metadata engine associated with the directory structure.