Virtualized boot block with discovery volume

• US 9,477,487 B2
• Filed: 10/07/2015
• Issued: 10/25/2016
• 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:
  US14/877,159
• Publication Number:
  US 20160026475A1
• Time in Patent Office: 384 Days
• 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 computing system comprising:

one or more processors

memory; and

a plurality of programming instructions stored on the memory and executable by the one or more processors to perform acts comprising;

moving contents of a primary boot block of a primary volume from a beginning of the primary volume to a new location in the primary volume;

providing a discovery volume at the beginning of the primary volume, the discovery volume enforcing read-only access over at least some of a space occupied by the primary volume; and

configuring a virtualized boot block for the discovery volume, one or more pointers in the virtualized boot block referring a boot block access request to the new location of the primary boot block for the primary volume.

2. The computing system of claim 1, wherein the primary volume is encrypted.

3. The computing system of claim 1, wherein the discovery volume is formatted according to a first file system type, and the primary volume is formatted according to a second file system type, different than the first file system type.

4. The computing system of claim 1, wherein the discovery volume includes data indicating that the discovery volume occupies the space occupied by the primary volume.

5. The computing system of claim 4, wherein the data indicating that the discovery volume occupies the space occupied by the primary volume includes entries in a file system table indicating that one or more cover files occupy some or all of the space occupied by the primary volume.

6. The computing system of claim 1, wherein the discovery volume enforcing read-only access includes data indicating that some or all the space occupied by the primary volume is read-only.

7. The computing system of claim 6, wherein the data indicating that that some or all the space occupied by the primary volume is read-only includes entries in a file system table indicating that one or more cover files in the discovery volume occupy some or all of the space occupied by the primary volume.

8. The computing system of claim 1, wherein the acts further comprise placing a driver in the discovery volume, the driver usable by an accessing computer system to access the primary volume.

9. A computing system comprising:

one or more processors;

memory; and

a plurality of programming instructions stored on the memory and executable by the one or more processors to perform acts comprising;

accessing a virtualized boot block of a discovery volume at a beginning of a primary volume on a storage media, the discovery volume enforcing read-only access over at least some of a space occupied by the primary volume;

accessing one or more pointers in the virtualized boot block to access a primary boot block for the primary volume; and

redirecting read to and write accesses from the discovery volume to the primary volume based at least on the one or more pointers.

10. The computing system of claim 9, wherein the primary volume is encrypted, and wherein the redirecting read to and write accesses from the discovery volume to the primary volume utilizes a driver to decrypt contents of the primary volume.

11. The computing system of claim 9, wherein the discovery volume is formatted according to a first file system type, and the primary volume is formatted according to a second file system type, different than the first file system type, and wherein the acts further comprise accessing the primary volume utilizing a driver stored on the storage media, the driver enabling access to the second file system type of the primary volume.

12. The computing system of claim 9, wherein the discovery volume includes data indicating that the discovery volume occupies the space occupied by the primary volume.

13. The computing system of claim 12, wherein the data indicating that the discovery volume occupies the space occupied by the primary volume includes entries in a file system table indicating that one or more cover read-only files occupy some or all of the space occupied by the primary volume.

14. The computing system of claim 9, wherein the discovery volume enforcing read-only access includes data indicating that some or all the space occupied by the primary volume is read-only.

15. The computing system of claim 14, wherein the data indicating that that some or all the space occupied by the primary volume is read-only includes entries in a file system table indicating that one or more cover files in the discovery volume occupy some or all of the space occupied by the primary volume.

16. A method, comprising:

accessing a storage device;

accessing a virtualized boot block of a discovery volume at a beginning of a primary volume on the storage device, the discovery volume enforcing read-only access over at least some of a space on the storage device occupied by the primary volume;

accessing one or more pointers in the virtualized boot block to access a primary boot block for the primary volume; and

redirecting read accesses and write accesses from the discovery volume to the primary volume based at least on the one or more pointers.

17. The method of claim 16, wherein the discovery volume is formatted according to a first file system type, and the primary volume is formatted according to a second file system type, different than the first file system type, and wherein the method further comprise accessing the primary volume utilizing a driver stored on the storage device, the driver enabling access to the second file system type of the primary volume.

18. The method of claim 16, further comprising accessing data on the discovery volume indicating that the discovery volume occupies the space on the storage device occupied by the primary volume.

19. The method of claim 18, wherein the data indicating that the discovery volume occupies the space on the storage device occupied by the primary volume includes entries in a file system table indicating that one or more cover read-only files occupy some or all of the space occupied by the primary volume.

20. The method of claim 16, further comprising accessing data on the discovery volume indicating that some or all the space occupied by the primary volume is read-only.