Virtualized boot block with discovery volume

• US 9,170,824 B2
• Filed: 08/12/2013
• Issued: 10/27/2015
• Est. Priority Date: 10/24/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Mehra, Karan, Thind, Ravinder S., Moss, Darren G., Ou-Yang, Darwin
• Primary Examiner(s): Casanova, Jorge A
• Application Number:
  US13/964,984
• Publication Number:
  US 20130339717A1
• Time in Patent Office: 806 Days
• Field of Search: 707/795, 707/796, 707/812, 707/831
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/1727 Details of free space management performed by the file system saving storage space on storage systems G06F3/0608; management of blocks in storage devices G06F3/064
• CPC Class Codes: G06F 16/1847 specifically adapted to static storage, e.g. adapted to flash memory or SSD
• CPC Class Codes: G06F 16/188 Virtual file systems
• CPC Class Codes: G06F 9/441 Multiboot arrangements, i.e. selecting an operating system to be loaded

Abstract

A file system independent virtualized boot block with discovery volume and cover files renders a volume visible when accessed by an accessing system which differs from a source system. For example, a downlevel operating system recognizes that data is present on a volume created in an uplevel operating system, even where the uplevel data itself may not be accessible.

Claims

1. A method comprising:

accessing, by a computing system, a virtualized boot block located at a virtualized boot block location within a primary volume;

identifying, by the computing system based on data stored within the virtualized boot block, a primary boot block location of the primary volume; and

redirecting, by the computing system, a boot block read request to a primary boot block located at the primary boot block location.

2. The method of claim 1, wherein the virtualized boot block is formatted according to a first file system format and the primary volume is formatted according to a second file system format, the first file system format differing from the second file system format.

3. The method of claim 1, further comprising redirecting a boot block write request to the primary boot block.

4. The method of claim 1, wherein the virtualized boot block location is at a beginning of the primary volume.

5. The method of claim 1, wherein the primary boot block is a relocated boot block, the relocated boot block having an original location, at least a portion of the original location of the boot block being occupied by the virtualized boot block location.

6. The method of claim 1, wherein the identifying the primary boot block location includes following a pointer that is present within the data, the pointer pointing to information that identifies the primary boot block location.

7. The method of claim 1, wherein the virtualized boot block is part of a discovery volume located within the primary volume, the data stored within the first virtualized boot block is first data, and wherein:

the identifying the primary boot block location includes identifying, from the first data, a different volume stored within the primary volume, and identifying the primary boot block location from second data stored within the different volume.

8. The method of claim 1, wherein the virtualized boot block location is a boot sector location of a partition of a physical storage device, the partition corresponding to the primary volume.

9. The method of claim 1, wherein the virtualized boot block is stored within a discovery volume stored within the primary volume, and the method further comprises:

accessing an access driver stored within the discovery volume; and

utilizing the access driver to redirect the boot block read request to the primary boot block.

10. A computing system, comprising:

a processor;

computer-readable storage media that stores instructions executable by the processor to perform acts, the acts comprising;

accessing a virtualized boot block located within a boot sector of a partition of a physical storage device coupled to the computing system, the partition corresponding to a primary volume of the physical storage device;

identifying, based at least on data stored within the virtualized boot block, a primary boot block location of the primary volume; and

redirecting read requests and write requests for a boot block location to a primary boot block of the primary volume located at the primary boot block location.

11. The computing system of claim 10, wherein the virtualized boot block is part of a discovery volume, and wherein the acts further comprise:

retrieving access software stored on the discovery volume; and

utilizing the access software to access the primary volume to redirect the read and write requests to the primary boot block.

12. The computing system of claim 11, wherein the access software provides decryption of the primary volume.

13. The computing system of claim 11, wherein the discovery volume is formatted according to a first file system format recognized by an operating system of the computing system, the primary volume is formatted according to a second file system format, and the access software provides the computing system with capabilities to access the second file system format of the primary volume.

14. The computing system of claim 10, wherein the virtualized boot block location is at a beginning of the primary volume, and wherein the primary boot block is a relocated boot block, the relocated boot block having an original location at the beginning of the primary volume.

15. The computing system of claim 10, wherein the acts further comprise identifying the primary boot block location by following a pointer that is present within the data, the pointer pointing to information that identifies the primary boot block location.

16. A computing system, comprising:

one or more computer-readable storage memories;

at least one processor; and

one or more modules stored on the one or more computer-readable memories and executable by the at least one processor to;

access a physical storage device that is coupled to the computing system, the access based on a virtualized boot block located on a discovery volume of the physical storage device;

identify, based on data stored within the discovery volume, a location of a primary boot block of a primary volume of the physical storage device; and

redirect boot block read and boot block write requests from the virtualized boot block to the primary boot block of the primary volume.

17. The computing system of claim 16, wherein the primary boot block is a relocated boot block of the primary volume.

18. The computing system of claim 16, wherein the discovery volume is formatted according to a first file format supported by an operating system, the primary volume is formatted according to a second file format unsupported by the operating system, the discovery volume further stores an access driver, and wherein the operating system is further executable to utilize the access driver to redirect the book block read requests and the boot block write requests to the primary boot block.

19. The computing system of claim 16, wherein the virtualized boot block is located at a boot sector of a partition of the physical storage device, the partition corresponding to the primary volume.

20. The computing system of claim 16, wherein the virtualized boot block is a first virtualized boot block, and the data stored within the first virtualized boot block is first data, and wherein:

the one or more modules are further executable by the at least one processor to;

identify, based on the first data, a location of a second virtualized boot block of a different volume stored within the primary volume, and

identify the location of the primary boot block from second data stored within the different volume.