METHODS AND SYSTEMS FOR INSTANT RESTORE OF SYSTEM VOLUME

• US 20140195791A1
• Filed: 01/08/2013
• Published: 07/10/2014
• Est. Priority Date: 01/08/2013
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Symantec Incorporated (NortonLifeLock Inc.)
• Inventors: TELI, Ravindra, SHAIKH, Mohammad Eliyas, DALAL, Chirag
• Granted Patent: US 9,384,094 B2
• Time in Patent Office: Days
• US Class Current: 713/2
• CPC Class Codes: G06F 11/1417 Boot up procedures
• CPC Class Codes: G06F 11/1469 Backup restoration techniques

Abstract

Techniques are disclosed for restoring a system volume on a computing system without requiring the system volume to be fully restored prior to being used or requiring the use of a dedicated recovery environment (e.g., the WinPE or BartPE environments). Instead, the computing system is booted directly from the restore image or by redirecting I/O interrupts to the restore image. That is, when user initiates a restore process, the system boots from the backup itself. Once booted, a background process can complete the restore process.

Claims

1. A computer-implemented method for restoring a system volume from a backup image, the method comprising:

prior to launching a boot loader on a computing system, receiving an indication to restore the system volume from the backup image;

redirecting an interrupt associated with disk I/O to a redirector function configured to perform read operations directed to the system volume from the backup image; and

launching the boot loader, wherein the boot loader is configured to load an operating system stored in the backup image.

2. The method of claim 1, wherein the interrupt is an INT13 interrupt on an x86 architecture.

3. The method of claim 1, further comprising:

after the boot loader turns over control for disk I/O to the operating system, launching a disk filter driver configured to perform read operations directed to the system volume from the backup image and to perform write operations by writing to the system volume.

4. The method of claim 3, wherein the disk filter driver is configured to complete restoring the system volume from the backup image by copying disk sectors from the backup image to the system volume.

5. The method of claim 1, wherein the backup image is stored in a virtual hard disk (VHD) formatted file.

6. The method of claim 1, wherein the backup image is stored on a local partition of a storage drive on the computing system.

7. The method of claim 1, wherein the redirector function performs a copy-on-read process to copy data read from the backup image to the system volume.

8. A computer-implemented method for restoring a system volume, the method comprising:

prior to launching a boot loader on a computing system, receiving an indication to restore the system volume from a virtual hard disk (VHD);

launching a disk filter driver configured to attach to a driver configured to perform disk I/O from the VHD, wherein the disk filter driver is configured to perform read operations directed to the system volume by reading from the VHD and to perform write operations by writing to the system volume; and

after booting an operating system stored on the VHD completing the restoring of the system volume from the backup image by copying disk sectors from the VHD to the system volume.

9. The method of claim 8, further comprising, after restoring the system volume, transitioning the disk filter driver to a pass through mode which directs disk I/O read and write requests to the restored system volume.

10. The method of claim 8, wherein the disk filter driver is configured to restore the system volume, at least in part, by performing a copy-on-read process for disk I/O reads directed to the VHD.

11. A computer-readable storage medium storing instructions, which, when executed on a processor, perform an operation for restoring a system volume from a backup image, the operation comprising:

prior to launching a boot loader on a computing system, receiving an indication to restore the system volume from the backup image; and

redirecting an interrupt associated with disk I/O to a redirector function configured to perform read operations directed to the system volume from the backup image; and

launching the boot loader, wherein the boot loader is configured to load an operating system stored in the backup image.

12. The computer-readable storage medium of claim 11, wherein the interrupt is an INT13 interrupt on an x86 architecture.

13. The computer-readable storage medium of claim 11, wherein the operation further comprises:

after the boot loader turns over control for disk I/O to the operating system, launching a disk filter driver configured to perform read operations directed to the system volume from the backup image and to perform write operations by writing to the system volume.

14. The computer-readable storage medium of claim 13, wherein the disk filter driver is configured to complete restoring the system volume from the backup image by copying disk sectors from the backup image to the system volume.

15. The computer-readable storage medium of claim 11, wherein the backup image is stored in a virtual hard disk (VHD) formatted file.

16. The computer-readable storage medium of claim 11, wherein the backup image is stored on a local partition of a storage drive on the computing system.

17. The computer-readable storage medium of claim 11, wherein the redirector function performs a copy-on-read process to copy data read from the backup image to the system volume.

18. A computer-readable storage medium storing instructions, which, when executed on a processor, perform an operation for restoring a system volume, the operation comprising:

prior to launching a boot loader on a computing system, receiving an indication to restore the system volume from a virtual hard disk (VHD);

launching a disk filter driver configured to attach to a driver configured to perform disk I/O from the VHD, wherein the disk filter driver is configured to perform read operations directed to the system volume by reading from the VHD and to perform write operations by writing to the system volume; and

after booting an operating system stored on the VHD completing the restoring of the system volume from the backup image by copying disk sectors from the VHD to the system volume.

19. The computer-readable storage medium of claim 18, wherein the operation further comprises, after restoring the system volume, transitioning the disk filter driver to a pass through mode which directs disk I/O read and write requests to the restored system volume.

20. The computer-readable storage medium of claim 18, wherein the disk filter driver is configured to restore the system volume, at least in part, by performing a copy-on-read process for disk I/O reads directed to the VHD.

21. A system, comprising:

a processor; and

a memory storing code, which, when executed on the processor, performs an operation for restoring a system volume from a backup image, the operation comprising;

prior to launching a boot loader on a computing system, receiving an indication to restore the system volume from the backup image,

redirecting an interrupt associated with disk I/O to a redirector function configured to perform read operations directed to the system volume from the backup image, and

launching the boot loader, wherein the boot loader is configured to load an operating system stored in the backup image.

22. The system of claim 21, wherein the interrupt is an INT13 interrupt on an x86 architecture.

23. The system of claim 21, wherein the operation further comprises:

after the boot loader turns over control for disk I/O to the operating system, launching a disk filter driver configured to perform read operations directed to the system volume from the backup image and to perform write operations by writing to the system volume.

24. The system of claim 23, wherein the disk filter driver is configured to complete restoring the system volume from the backup image by copying disk sectors from the backup image to the system volume.