Continuous Data Protection of Files Stored on a Remote Storage Device

• US 20100017444A1
• Filed: 05/27/2009
• Published: 01/21/2010
• Est. Priority Date: 07/15/2008
• Status: Active Grant

• Current Assignee: AmZetta Technologies, LLC (American Megatrends International, LLC)
• Original Assignee: American Megatrends Incorporated
• Inventors: Narayanan, Ajit, Samuel Enoch, Sharon, Chatterjee, Paresh
• Granted Patent: US 8,706,694 B2
• Time in Patent Office: Days
• US Class Current: N/A
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

Technologies are described herein for providing file-level CDP of files stored on a remote storage system. A client module executing on a client computer monitors for modifications made at the client computer to files or folders stored on a virtual storage volume provided by the remote storage system. Upon detecting a modification of a monitored file, the client module sends a message to the remote storage system identifying the file. A server module executing in the remote storage system receives the message identifying the modified file and copies a version of the file containing the modification from the virtual storage volume to a backup volume located in the remote storage system.

Claims

1. A computer-implemented method for providing continuous data protection (“

CDP”

) for a file stored on a virtual storage volume in a data storage system, the method comprising;

executing a CDP client module on a client computer utilizing the virtual storage volume for storage, the CDP client module configured to

detect a modification to the file stored on the virtual storage volume made at the client computer, and

upon detecting the modification, send a message to the data storage system identifying the file and indicating a time of the modification; and

executing a CDP server module in the data storage system containing the virtual storage volume, the CDP server module configured to

receive the message identifying the file and indicating the time of the modification,

determine if a time of last update of the file on the virtual storage volume substantially matches the time of the modification, and

upon determining that the time of last update of the file on the virtual storage volume substantially matches the time of the modification, copy a version of the file containing the modification from the virtual storage volume to a backup volume in the data storage system.

2. The method of claim 1, wherein the virtual storage volume is a storage area network (“

SAN”

) volume.

3. The method of claim 2, wherein the CDP server module accesses the file on the virtual storage volume by mounting the SAN volume through a file system driver.

4. The method of claim 1, wherein the backup volume is a network attached storage (“

NAS”

) volume.

5. The method of claim 1, wherein the CDP server module is further configured to apply one or more of compression and encryption to the version of the file copied to the backup volume.

6. The method of claim 1, wherein the CDP client module is further configured to, upon detecting the modification to the file, wait a specific period of time before sending the message in order to ensure a write cache for the virtual storage volume has been flushed.

7. The method of claim 1, wherein the CDP server module is further configured to, upon determining that the time of last update of the file on the virtual storage volume does not substantially match the time of the modification, force a flush of a read cache for the virtual storage volume and then re-determine if the time of last update of the file on the virtual storage volume substantially matches the time of the modification.

8. A computer-readable storage medium having computer-executable instructions stored thereon that, when executed by a computer utilizing a virtual storage volume in a data storage system for storage, cause the computer to:

detect a modification to a file stored on the virtual storage volume made at the computer; and

upon detecting the modification, send a message to the data storage system identifying the file,

wherein the data storage system is configured to receive the message identifying the file and copy a version of the file containing the modification from the virtual storage volume to a backup volume in the data storage system.

9. The computer-readable storage medium of claim 8, wherein the message further indicates a time of the modification to the file, and wherein the data storage system is further configured to only copy the version of the file to the backup volume upon determining that a time of last update of the file on the virtual storage volume substantially matches the time of the modification.

10. The computer-readable storage medium of claim 8, wherein the virtual storage volume is a storage area network (“

SAN”

) volume.

11. The computer-readable storage medium of claim 8, wherein the backup volume is a network attached storage (“

NAS”

) volume.

12. The computer-readable storage medium of claim 8, wherein the data storage system is further configured to apply one or more of compression and encryption to the version of the file copied to the backup volume.

13. The computer-readable storage medium of claim 8, having further computer-executable instructions stored thereon that, when executed by the computer, cause the computer to, upon detecting the modification to the file, wait a specific period of time before sending the message in order to ensure a write cache for the virtual storage volume has been flushed.

14. The computer-readable storage medium of claim 9, wherein the data storage system is further configured to, upon determining that the time of last update of the file on the virtual storage volume does not substantially match the time of the modification, force a flush of a read cache for the virtual storage volume and then re-determine if the time of last update of the file on the virtual storage volume substantially matches the time of the modification.

15. A system for continuously protecting a file stored on a virtual storage volume of a data storage system, the system comprising:

a client module executing on a client computer utilizing the virtual storage volume for storage, the client module configured to

detect a modification to the file stored on the virtual storage volume made at the client computer, and

upon detecting the modification, send a message to the data storage system identifying the file and indicating a time of the modification; and

a server module executing on the data storage system containing the virtual storage volume, the server module configured to

receive the message identifying the file and indicating the time of the modification,

determine if a time of last update of the file on the virtual storage volume substantially matches the time of the modification, and

upon determining that the time of last update of the file on the virtual storage volume substantially matches the time of the modification, copy a version of the file containing the modification from the virtual storage volume to a backup volume in the data storage system.

16. The system of claim 15, wherein the virtual storage volume is a storage area network (“

SAN”

) volume.

17. The system of claim 15, wherein the backup volume is a network attached storage (“

NAS”

) volume.

18. The system of claim 15, wherein the server module is further configured to apply one or more of compression and encryption to the version of the file copied to the backup volume.

19. The system of claim 15, wherein the client module is further configured to, upon detecting the modification to the file, wait a specific period of time before sending the message in order to ensure a write cache for the virtual storage volume has been flushed.

20. The system of claim 15, wherein the server module is further configured to, upon determining that the time of last update of the file on the virtual storage volume does not substantially match the time of the modification, force a flush of a read cache for the virtual storage volume and then re-determine if the time of last update of the file on the virtual storage volume substantially matches the time of the modification.