Moving data from file on storage volume to alternate location to free space

• US 20070016618A1
• Filed: 07/14/2005
• Published: 01/18/2007
• Est. Priority Date: 07/14/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Suriyanarayanan, Guhan, Mohamed, Ahmed, Robert, Christophe, Havewala, Sarosh
• Granted Patent: US 7,506,003 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/1737 for reducing power consumption or coping with limited storage space, e.g. in mobile devices saving storage space on storage devices G06F3/0608; power saving in storage systems G06F3/0625
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

To reconstitute a ghosted file for use, a single ghosting filter on a computing device locates ghosting information in the metadata of the ghosted file and locates within the ghosting information an identification of a particular ghosting manager of the computing device, where the identified ghosting manager is responsible for the ghosted file. Thereafter, the ghosting filter communicates to the identified ghosting manager a request to obtain data of the ghosted file from a corresponding alternate location, and the identified ghosting manager does in fact obtain such requested data from such alternate location. Upon receiving the requested data of the ghosted file from the identified ghosting manager, then, the ghosting filter reconstitutes the received data to the ghosted file. The single ghosting filter is generic to all of the ghosting managers of the computing device.

Claims

1. A method in connection with a computing device having a storage volume, a file system managing the storage volume, and a plurality of files stored on the storage volume by the file system and accessed by such file system, each file being defined to include data and metadata relating to the data, at least a portion of the data of the file having been removed from the file and stored at one of a plurality of alternate locations such that the data does not occupy substantially any space on the volume and the file is in a reduced, ghosted form, the computing device further having for each of the plurality of alternate locations a corresponding ghosting manager, each ghosting manager for being employed to communicate with the alternate location corresponding thereto, the method for reconstituting a ghosted file for use and comprising a single ghosting filter on the computing device:

locating ghosting information in the metadata of the ghosted file;

locating within the ghosting information an identification of a particular ghosting manager of the computing device, the identified ghosting manager being responsible for the ghosted file;

communicating to the identified ghosting manager a request to obtain data of the ghosted file from the corresponding alternate location, whereby the identified ghosting manager does in fact obtain such requested data from such alternate location;

receiving the requested data of the ghosted file from the identified ghosting manager; and

reconstituting the received data to the ghosted file,

whereby the single ghosting filter is generic to all of the ghosting managers of the computing device.

2. The method of claim 1 comprising communicating to the identified ghosting manager a request to obtain a portion of the data of the ghosted file from the corresponding alternate location.

3. The method of claim 1 comprising communicating to the identified ghosting manager a request to obtain all of the data of the ghosted file from the corresponding alternate location.

4. The method of claim 1 wherein the computing device is a branch server and each alternate location is a hub server remote from the branch server, the hub server servicing a plurality of such branch servers.

5. The method of claim 1 wherein the metadata of the ghosted file as resident on the volume includes substantially all the metadata from the file prior to ghosting, and also contains the ghosting information for being employed to retrieve the data for the file from the alternate location.

6. The method of claim 1 wherein the file is defined to include data including primary data and secondary data, the primary data being larger than the secondary data, at least the primary data of the file having been removed from the file and stored at the alternate location.

7. A method in connection with a computing device having a storage volume, a file system managing the storage volume, and a plurality of files stored on the storage volume by the file system and accessed by such file system, each file being defined to include data and metadata relating to the data, at least a portion of the data of the file having been removed from the file and stored at one of a plurality of alternate locations such that the data does not occupy substantially any space on the volume and the file is in a reduced, ghosted form, the computing device further having for each of the plurality of alternate locations a corresponding ghosting manager, each ghosting manager for being employed to communicate with the alternate location corresponding thereto, the method for reconstituting a ghosted file for use and comprising:

locating ghosting information in the metadata of the ghosted file;

locating within the ghosting information an identification of a particular ghosting manager of the computing device, the identified ghosting manager being responsible for the ghosted file;

communicating to the identified ghosting manager a request to obtain data of the ghosted file from the corresponding alternate location, whereby the identified ghosting manager does in fact obtain such requested data from such alternate location;

receiving the requested data of the ghosted file from the identified ghosting manager; and

reconstituting the received data to the ghosted file.

8. The method of claim 7 comprising communicating to the identified ghosting manager a request to obtain a portion of the data of the ghosted file from the corresponding alternate location.

9. The method of claim 7 comprising communicating to the identified ghosting manager a request to obtain all of the data of the ghosted file from the corresponding alternate location.

10. The method of claim 7 wherein the computing device is a branch server and each alternate location is a hub server remote from the branch server, the hub server servicing a plurality of such branch servers.

11. The method of claim 7 wherein the metadata of the ghosted file as resident on the volume includes substantially all the metadata from the file prior to ghosting, and also contains the ghosting information for being employed to retrieve the data for the file from the alternate location.

12. The method of claim 7 wherein the file is defined to include data including primary data and secondary data, the primary data being larger than the secondary data, at least the primary data of the file having been removed from the file and stored at the alternate location.

13. A computing device having:

a storage volume;

a file system managing the storage volume; and

a plurality of files stored on the storage volume by the file system and accessed by such file system, each file being defined to include data and metadata relating to the data, at least a portion of the data of the file having been removed from the file and stored at one of a plurality of alternate locations such that the data does not occupy substantially any space on the volume and the file is in a reduced, ghosted form,

the computing device further having for each of the plurality of alternate locations a corresponding ghosting manager, each ghosting manager for being employed to communicate with the alternate location corresponding thereto, each ghosted file on the computing device having ghosting information in the metadata thereof, the ghosting information including an identification of a particular ghosting manager of the computing device, the identified ghosting manager being responsible for the ghosted file,

whereby each ghosted file may be reconstituted by locating within the ghosting information thereof an identification of a particular ghosting manager of the computing device, the identified ghosting manager being responsible for the ghosted file, and communicating to the identified ghosting manager a request to obtain data of the ghosted file from the corresponding alternate location, the identified ghosting manager in fact obtaining such requested data from such alternate location and the obtained data being reconstitute to the ghosted file.

14. The device of claim 13 wherein the computing device is a branch server and each alternate location is a hub server remote from the branch server, the hub server servicing a plurality of such branch servers.

15. The device of claim 13 wherein the metadata of the ghosted file as resident on the volume includes substantially all the metadata from the file prior to ghosting, and also contains the ghosting information for being employed to retrieve the data for the file from the alternate location.

16. The device of claim 13 wherein the file is defined to include data including primary data and secondary data, the primary data being larger than the secondary data, at least the primary data of the file having been removed from the file and stored at the alternate location.