System and method for disk imaging on diverse computers

• US 8,209,680 B1
• Filed: 06/30/2003
• Issued: 06/26/2012
• Est. Priority Date: 04/11/2003
• Status: Active Grant

• Current Assignee: Vmware LLC (Broadcom, Inc.)
• Original Assignee: VMware, Inc. (Broadcom, Inc.)
• Inventors: Le, Bich C., Khandekar, Dilip, Raghuram, Sirishkumar
• Primary Examiner(s): Zhen, Wei
• Assistant Examiner(s): Chen, Qing
• Application Number:
  US10/611,815
• Time in Patent Office: 3,284 Days
• Field of Search: 717/134, 717/135, 717168-178, 713/1, 713/2, 713/100
• US Class Current: 717/174
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/116 Details of conversion of file system types or formats
• CPC Class Codes: G06F 16/166 File name conversion
• CPC Class Codes: G06F 16/188 Virtual file systems
• CPC Class Codes: G06F 2009/45562 Creating, deleting, cloning virtual machine instances
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

A system is disclosed that uses a dual loopback mounting mechanism to capture and deploy an image of a source disk with no need for the source disk to be loaded with special software or otherwise prepared. The image may be captured even where the source disk uses a proprietary file system. The invention also provides mechanisms to extract a system'"'"'s hardware configuration from a static image of its disk, and to catalog, warehouse, reconfigure, customize, and deploy disk images on diverse computers. Still other mechanisms are provided to perform efficient physical-to-virtual, virtual-to-physical, and virtual-to-virtual system migration.

Claims

1. A method for creating an image of a source disk of a first computer on a destination disk of a second computer that includes an operating system and file system software, the method comprising:

mounting in the second computer, a simulated source disk corresponding to the source disk of the first computer such that the simulated source disk is accessible by the operating system in the second computer as a local disk, the file system software within the second computer detecting a file system of the mounted simulated source disk, exposing the file system to the software running on the second computer, and issuing sector-based I/O requests toward the simulated source disk;

intercepting sector-based I/O requests directed to the simulated source disk and retrieving source disk data from the source disk according to the intercepted sector-based I/O requests such that contents of the source disk in the first computer are extracted at the sector level and system software in the first computer need not detect the file system of the source disk;

creating a destination image as a virtual disk; and

populating the destination image in the destination disk of the second computer with the contents of the source disk such that the destination image has a different sector-by-sector content than the source disk but a destination file system logically equivalent to the source file system.

2. The method as in claim 1, further comprising:

populating the destination image with extracted contents of the source disk in which the destination image has files, attributes, and structural relationships between files identical to files associated with the source disk.

3. The method as in claim 2, further comprising:

mounting the destination image in an uninitialized state in the second computer as a simulated destination disk;

intercepting sector-based I/O requests directed to the simulated destination disk and directing the contents of the intercepted sector-based I/O requests to the destination image;

retrieving partition and file system layout information from the source disk;

formatting the simulated destination disk to have the same partitioning and file system as the simulated source disk and thus of the source disk; and

copying files of at least one file system of the simulated source disk to the corresponding file system of the simulated destination disk.

4. The method as in claim 3, further comprising:

converting the intercepted sector-based I/O requests to the simulated destination disk into sector accesses within the destination image.

5. The method as in claim 3, wherein the first computer is a physical computer and the source disk is a physical disk associated with the physical computer.

6. The method as in claim 3, wherein the virtual disk is a sparse virtual disk having a predetermined capacity and initial sector contents with null values.

7. The method as in claim 3, wherein the source disk is a source virtual disk.

8. The method as in claim 7, wherein the destination disk is a physical disk.

9. The method as in claim 3, wherein the source disk is a first virtual disk associated with a first virtual computer and the destination disk is a second virtual disk associated with a second virtual computer.

10. The method as in claim 3, wherein the first computer is the same as the second computer.

11. The method as in claim 1, further comprising forwarding the intercepted sector-based I/O requests to the first computer over a network.

12. The method as in claim 1, wherein the source disk is associated with the first computer that has a memory, further comprising:

loading an imaging client program in the memory of the first computer, the imaging client program not being resident on the source disk; and

passing the intercepted sector-based I/O requests to the imaging client program, the imaging client program directing the intercepted sector-based I/O requests to the source disk.

13. The method as in claim 12, further comprising:

loading a secondary operating system in the memory of the first computer, the secondary operating system not being present on the source disk and mediating I/O requests between the imaging client program and the source disk.

14. The method as in claim 1, wherein the simulated source disk is a file presented to the operating system of the second computer as a physical disk.

15. The method as in claim 1, wherein the source disk in the first computer need not be modified prior to mounting the simulated source disk in the second computer.

16. A method for creating an image of a source disk of a first computer on a destination disk of a second computer that includes an operating system and file system software, the method comprising:

mounting in the second computer, a simulated source disk corresponding to the source disk of the first computer such that the simulated source disk is accessible by the operating system in the second computer as a local disk, the file system software within the second computer detecting a file system of the mounted simulated source disk, exposing the file system to the software running on the second computer, and issuing sector-based I/O requests toward the simulated source disk;

intercepting sector-based I/O requests directed to the simulated source disk and retrieving source disk data from the source disk according to the intercepted sector-based I/O requests such that contents of the source disk in the first computer are extracted at the sector level and system software in the first computer need not detect the file system of the source disk;

creating a destination image as a virtual disk;

mounting the destination image in an uninitialized state in the second computer as a simulated destination disk accessible by the operating system of the second computer, such that sector-based I/O requests directed to the simulated destination disk are intercepted and converted into sector accesses within the destination image;

retrieving partition and file system layout information from the source disk in the first computer;

formatting the simulated destination image to have the same partitioning and file system(s) as the simulated source disk, which has the same partitioning and file system(s) as the source disk in the first computer; and

populating the destination image in the destination disk of the second computer with the contents of the source disk such that the destination image has a different sector-by-sector content than the source disk but a destination file system logically equivalent to the source file system.

17. The method of claim 16, further comprising:

loading an imaging client program into a memory of the first computer;

passing the intercepted sector-based I/O requests to the imaging client program, the imaging client program directing the intercepted sector-based I/O requests to the source disk; and

mediating, by the operating system of the second computer, sector-based I/O requests between the imaging client program and the source disk.

18. A system for creating an image of a source disk of a first computer with contents arranged according to at least one file system on a destination disk of a second computer, the system comprising:

a first computer having the source disk; and

a second computer having a memory with an operating system, file system software, and a destination disk and including computer-executable instructions for;

creating a simulated source disk with a representation of information stored on the source disk in the first computer;

mounting the simulated source disk in the second computer such that the simulated source disk is accessible by the operating system in the second computer as a local disk, the memory of the second computer further including file system software to detect a file system of the simulated source disk, to expose the file system to the software running on the second computer, and to issue sector-based I/O requests toward the simulated source disk;

intercepting sector-based I/O requests directed to the simulated source disk and retrieving source disk data from the source disk according to the intercepted sector-based I/O requests such that contents of the source disk in the first computer are extracted at the sector level and system software in the first computer need not detect the file system of the source disk;

creating a destination image as a virtual disk; and

populating the destination image in the destination disk of the second computer with the contents of the source disk such that the destination image has a different sector-by-sector content than the source disk but a destination file system logically equivalent to the source file system.

19. The system as in claim 18, further comprising:

a network adapter, residing in the memory of the second computer, to forward the intercepted sector-based I/O requests to the first computer.

20. The system as in claim 19, further comprising:

a memory within the first computer; and

an imaging client program installed in the memory of the first computer, the imaging client program comprising computer-executable instructions for;

receiving any source disk I/O requests issued from the second computer to the first computer;

directing the intercepted sector-based I/O requests to the source disk; and

passing the retrieved source disk data to the second computer in response to the source disk I/O requests.

21. The system as in claim 18, further comprising:

an imaging server program installed in the memory of the second computer, the imaging server program comprising computer-executable instructions for generating a simulated destination disk in response to the second computer mounting the destination image, the memory of the second computer further includes a local loop-back driver, a local adapter, and a formatting module, the local loop-back driver comprising computer-executable instructions for intercepting sector-based I/O requests directed to the simulated destination disk and retrieving partition and file system layout information from the source disk, the local adapter comprising computer-executable instructions for converting the intercepted sector-based I/O requests to the simulated destination disk into sector accesses within the destination image, and the formatting module comprising computer-executable instructions for formatting the destination image to have the same partitioning and file system(s) as the simulated source disk and thus of the source disk, wherein the imaging server program further comprising computer-executable instructions for copying files of at least one file system of the simulated source disk to the corresponding file system of the simulated destination disk.

22. The system as in claim 21, wherein the source disk is a virtual disk.

23. The system as in claim 22, wherein the destination disk is a physical disk.

24. The system as in claim 21, wherein the first computer is a physical computer and the source disk is a physical disk associated with the physical computer.

25. A system for creating an image of a source disk of a first computer, which has a memory and in which contents of the source disk are arranged according to at least one source file system, the system comprising:

a second computer including an operating system, file system software, a processor, and a memory coupled to the processor configured to provide the processor with computer-executable instructions for;

mounting in the second computer, a simulated source disk corresponding to the source disk of the first computer such that the simulated source disk is accessible by the operating system in the second computer as a local disk, the file system software within the second computer detecting a file system of the mounted simulated source disk, exposing the file system to the software running on the second computer, and issuing sector-based I/O requests toward the simulated source disk;

intercepting sector-based I/O requests directed to the simulated source disk and retrieving source disk data from the source disk according to the intercepted sector-based I/O requests such that contents of the source disk in the first computer are extracted at the sector level and system software in the first computer need not detect the file system of the source disk;

creating a destination image as a virtual disk;

mounting the destination image in an uninitialized state in the second computer as a simulated destination disk accessible by the operating system of the second computer, such that sector-based I/O requests directed to the simulated destination disk are intercepted and converted into sector accesses within the destination image;

retrieving partition and file system layout information from the source disk in the first computer;

formatting the simulated destination image to have the same partitioning and file system(s) as the simulated source disk, which has the same partitioning and file system(s) as the source disk in the first computer; and

populating the destination image in the destination disk of the second computer with the contents of the source disk such that the destination image has a different sector-by-sector content than the source disk but a destination file system logically equivalent to the source file system.

26. The system of claim 25, further comprising:

an imaging client program installed in the memory of the first computer, the imaging client program comprising computer-executable instructions for;

receiving any source disk I/O requests issued from the second computer to the first computer;

directing the intercepted sector-based I/O requests to the source disk; and

passing the retrieved source disk data to the second computer in response to the source disk I/O requests.