Transactional multi-package installation

• US 20090125573A1
• Filed: 10/10/2007
• Published: 05/14/2009
• Est. Priority Date: 10/10/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Hardy, Edward W.
• Granted Patent: US 7,945,587 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 3/0623 in relation to content
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0671 In-line storage system

Abstract

Described is a technology by which storage space in the form of allocation units (e.g., clusters of a storage volume) are intentionally allocated so as to likely be non-contiguous for a file'"'"'s data. For example, random selection of each of the allocation units will likely provide non-contiguous allocation units; on solid state storage media, such a random distribution of a file'"'"'s data does not significantly affect access times. In one aspect, a file system driver randomly allocates the allocation units, and records the allocation units in association with the file, e.g., in a master file table or similar database. Non-contiguous (e.g., random) allocation may be on demand as storage space is needed, and/or may be performed in anticipation of needing storage space for satisfying a later request. Once the storage space is no longer mapped to a file, reconstructing that file'"'"'s data in forensic analysis is more difficult.

Claims

1. A computer-readable medium having computer-executable instructions, which when executed perform steps, comprising:

processing a request that corresponds to a need to allocate storage space comprising a plurality of allocation units; and

allocating the storage space, including intentionally providing space that likely corresponds to non-contiguous allocation units.

2. The computer-readable medium of claim 1 wherein allocating the storage space comprises randomly selecting at least one allocation unit.

3. The computer-readable medium of claim 2 wherein randomly selecting comprises selecting the at least one allocation unit on demand based on the request.

4. The computer-readable medium of claim 2 wherein randomly selecting comprises selecting the at least one allocation unit prior to the request in anticipation of the request.

5. The computer-readable medium of claim 1 wherein the request to allocate storage space corresponds to a file, and wherein allocating the storage space comprises mapping the space in association with the file.

6. The computer-readable medium of claim 5 having further computer-executable instructions comprising, erasing the mapping.

7. The computer-readable medium of claim 1 wherein processing the request to allocate storage space comprises processing a file write request.

8. In a computing environment, a system comprising:

a storage media that is configured as a storage volume, including having allocation units; and

a file system including a driver component that allocates allocation-units of the storage volume in response to requests to allocate storage space, the file system configured to randomly select at least one allocation unit to satisfy an allocation request that corresponds to a file, and to record an association between the file and each allocation unit that is allocated to satisfy the request.

9. The system of claim 8 wherein the storage media comprises solid state media.

10. The system of claim 8 wherein the allocation unit comprises a cluster.

11. The system of claim 8 wherein the allocation unit comprises a cluster, wherein the file system comprises an NTFS-type file system, and wherein the file system records an association between the file and each allocation unit in a master file table of the storage volume.

12. The system of claim 8 further comprising a randomizing mechanism coupled to the storage volume to separate a file having sequential or mostly sequential allocation units into a file having randomly distributed allocation units.

13. The system of claim 8 wherein the file system driver randomly selects the at least one allocation unit by accessing a free space data structure.

14. The system of claim 13 wherein the free space data structure comprises a bitmap that for each allocation unit includes a value that indicates whether the allocation unit is already allocated or is free.

15. The system of claim 13 wherein the free space data structure comprises a table that tracks allocation units that are free.

16. In a computing environment, a method comprising:

processing a request corresponding to a need to allocate storage space for file data of a file;

allocating storage space based on the request on a storage volume comprising solid-state storage media, including selecting randomly distributed allocation units from available free space as allocated storage space for the file data; and

recording the allocated storage space in a set of mappings maintained in association with the storage volume, the mappings indicating which allocation units are associated with the file.

17. The method of claim 16 further comprising, processing the set of mappings to read back the file data.

18. The method of claim 16 further comprising, erasing the set of mappings.

19. The method of claim 16 wherein selecting the randomly distributed allocation units comprises, selecting at least one allocation unit on demand based on the request, or selecting at least one allocation unit prior to the request in anticipation of receiving the request, or any combination of selecting at least one allocation unit on demand based on the request and selecting at least one allocation unit prior to the request in anticipation of receiving the request.

20. The method of claim 16 wherein processing the request includes determining that the request is one that is to have randomly distributed allocation units.