Method and system of converting data from a source file system to a target file system

• US 5,742,818 A
• Filed: 12/15/1995
• Issued: 04/21/1998
• Est. Priority Date: 12/15/1995
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Shoroff, Srikanth, Milewski, Bartosz Boleslaw
• Primary Examiner(s): Lintz, Paul R.
• Application Number:
  US08/573,479
• Time in Patent Office: 858 Days
• Field of Search: 395/616, 395/712
• US Class Current: 1/1
• CPC Class Codes: G06F 16/116 Details of conversion of file system types or formats
• CPC Class Codes: G06F 16/1794 Details of file format conversion
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A method for converting a source file system to a target file system while maintaining data integrity is disclosed. Calls to the target file system are used to convert the files in the source file system to files in the target file system. After creating a minimal target file system by placing data structures for the target file system on the disk, the data structures, directories and file data for the source file system are stored in a new file on the target file system. Data associated with the files from the source file system are passed out of the new file and provided to the target file system to create files on the target file system, thereby completing the conversion.

Claims

1. A method of converting a source file system containing meta data and data files to a target file system while maintaining the data integrity of the data files, comprising the steps of:

creating target file system meta information;

saving the data files and meta data of the source file system in one or more target files in the target file system;

parsing data associated with files of the source file system out of the one or more target files; and

providing the parsed data to the target file system with instructions to the target file system to save the parsed data as files in the target file system.

2. The method as described in claim 1 wherein the target file system meta information is placed in the free space of the source file system.

3. The method as described in claim 1 further comprising the step of compacting the data files on the source file system prior to the step of saving the data files and meta data of the source file system in one or more target files in the target file system.

4. The method as described in claim 1 further comprising the step of compacting the one or more target files during the conversion to free additional space in the target file system.

5. The method as described in claim 1 wherein the instructions to the target file system to save the parsed data as files in the target file system includes the instructions to create new target files using the parsed data.

6. The method as described in claim 1 wherein the instructions to the target file system to save the parsed data as files in the target file system includes the instruction to create pointers to the parsed data located within the one or more target files, thereby obviating the need to copy the data from the one or more target files to a new target file.

7. The method as described in claim 6 wherein the pointers in the target file system are created based on the file location and file size of the file associated with the parsed data.

8. The method as described in claim 1 wherein the instructions to the target file system comprise target file system calls.

9. A method of converting a source file system containing meta data and data files to a target file system while maintaining the data integrity of the data files, comprising the steps of:

creating target file system meta information;

creating a file in the target file system, the file corresponding to data of the source file system, by using calls in the target file system to copy the data of the source file system to the target file system; and

using a primary copy and a backup copy of the source file system meta information for error prevention.

10. The method as described in claim 9 wherein the primary copy is updated as the data of the source file system is copied to the target file system.

11. The method as described in claim 10 wherein the backup copy is used in the event of a failure while updating the primary copy.

12. A method of converting a source file system containing meta data and data files to a target file system while maintaining the data integrity of the data files, comprising the steps of:

creating target file system meta information;

executing commands of the target file system to convert the source file system to the target file system; and

deleting source file system meta information.

13. The method as described in claim 12 wherein the target file system commands include creating files in the target file system using the data from the source file system.

14. The method as described in claim 13 wherein the data from the source file system is copied and then saved by the target file system.

15. The method as described in claim 13 wherein the location of the data from the source file system is provided to the target file system to update the target file system meta information.

16. A file conversion utility for converting a source file system containing meta data and data files to a target file system while maintaining the data integrity of the data files, said file conversion utility comprising:

means for creating target file system meta information;

means for saving the data files and meta data of the source file system in one or more target files in the target file system;

means for parsing data associated with files of the source file system out of the one or more target files; and

means for providing the parsed data to the target file system with instructions to the target file system to save the parsed data as files in target file system.