System and method for reading and writing disks formatted for an operating system foreign to the host computer

• US 5,537,592 A
• Filed: 01/23/1995
• Issued: 07/16/1996
• Est. Priority Date: 05/08/1989
• Status: Expired due to Term

• Current Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Original Assignee: Alphatronix, Inc.
• Inventors: King, Dianne L., Whisler, John W.
• Primary Examiner(s): Heckler, Thomas M.
• Application Number:
  US08/376,455
• Time in Patent Office: 540 Days
• Field of Search: 395/200, 395/500, 395/600, 395/700
• US Class Current: 707/756
• CPC Class Codes: G06F 16/258 Data format conversion from or to a database
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: Y10S 707/956 Hierarchical

Abstract

The present invention provides an independent set of processes and data structures that allow data transfer between differently formatted disks of files specified by the user. The processes identify the file format of the disks, retrieve the files in the source file format, store the source files in a common format in memory that allows the directory hierarchy of the disks to be maintained, translates the files to the format of the destination file system disk, creates index information for the destination disk, and stores the files, directories and indexes on the destination disk in the destination file format. The user can then access and modify the files and transfer the modified files back to the foreign disk in the foreign file format using the same transfer processes. The common memory format is a data structure which is a two dimensional list with one dimension maintaining the directory hierarchy of the source disk and the second dimension maintaining the hierarchy of the destination disk. Data and directory rings are used to store file contents as they are transferred from one disk to the other and pagable windows storing the contents of index files on the source and destination disks are used to enhance transfer speed.

Claims

1. A file transfer method performed in a computer having an operating system, comprising the steps of:

reading files from a first disk having a first file format with a first file format definition including a first directory structure and a first file structure using;

a computer;

means for reading the first disk; and

a read process separate from and bypassing the operating system and with the read process controlling a reading operation of the first disk by the means for reading and which reading operation bypasses the operating system; and

writing the files to a second disk having a second file format with a second file format definition including a second directory structure and a second file structure using;

the computer;

means for writing the second disk and a write process separate from and bypassing the operating system and for transforming contents read from the first disk into the second file format and the write process controlling writing operations to the second disk by the means for writing and which writing operation bypasses the operating system.

2. A file transfer method performed in a computer having an operating system, comprising the steps of:

reading files from a first disk having a first file format using;

a computer;

means for reading the first disk; and

a read process separate from and bypassing the operating system and the read process controlling a reading operation of the first disk by the means for reading and which bypasses the operating system; and

writing the files to a second disk having a second file format using;

the computer;

means for writing the second disk and a write process separate from and bypassing the operating system and for transforming contents read from the first disk into the second file format and the write process controlling writing operations to the second disk by the means for writing and which bypasses the operating system and, further comprising asking a user to specify the first and second file formats and performing the transforming of the files from the first format to the second format responsive to the user specifying the first and second formats.

3. A file transfer method performed in a computer having an operating system, comprising the steps of:

reading files from a first disk having a first file format using;

a computer;

means for reading the first disk; and

a read process separate from and bypassing the operating system and the read process controlling a reading operation of the first disk by the means for reading and which read process bypasses the operating system; and

writing the files to a second disk having a second file format using;

the computer;

means for writing the second disk and a write process separate from and bypassing the operating system and for transforming contents read from the first disk into the second file format and the write process controlling writing operations to the second disk by the means for writing and which write process bypasses the operating system, and

wherein said reading step includes determining the first file format from contents of the first disk and said writing step includes determining the second file format from contents of the second disk and the reading and writing steps including the steps of reading and writing the files responsive to the determined first and second formats, respectively.

4. A method as recited in claim 3,

further comprising the steps, during said reading, of:

storing first disk file contents on a source file contents ring;

storing first disk directory contents on a source directory ring;

creating a two-dimensional list from the first directory contents having a first dimension coordinating a disk directory structure and having a second dimension coordinating a disk file structure; and

further comprising the steps, during said writing, of;

storing the contents of the source file contents ring on a destination file contents ring responsive to the two dimensional list used as a guide to maintaining correct directory order; and

storing second directory contents on a destination directory ring responsive to the two dimensional list used as a guide to maintaining correct directory order.

5. A method as recited in claim 4, further comprising creating and writing headers for files and directories for the second disk.

6. A method as recited in claim 5, further comprising moving file contents stored on the source file contents ring to the destination file contents ring and translating the file contents from the first format to the second format during the moving.

7. A method as recited in claim 6, further comprising controlling access to the rings and list.

8. A method as recited in claim 4, wherein said destination and source file contents rings are the same ring.

9. A file transfer method performed in a computer having an operating system, comprising the steps of:

determining a first file format from contents of a first disk;

determining a second file format from contents of a second disk;

reading files from the first disk, the files having the first file format using the;

computer;

disk reading means for reading the first disk; and

a read process separate from and bypassing the operating system and the read process controlling reading operations of the first disk by the disk reading means and which read process bypasses the operating system;

storing first disk file contents of the files obtained during reading on a source file contents ring;

storing first disk directory contents of the files obtained during reading on a source directory ring;

creating a two-dimensional list from the directory contents having a first dimension coordinating a first directory structure of the first disk and having a second dimension coordinating a second directory structure of the second disk;

storing second directory contents for the second file contents on a destination directory ring based on the second directory structure of the two dimensional list for maintaining correct directory order;

transferring the contents of the source file contents ring to a destination file contents ring;

creating headers for the files and directories for the second disk;

writing the files from the destination field contents ring, directories from the destination directory ring and the headers to the second disk having the second file format using;

the computer;

disk writing means for writing the second disk; and

a write process separate from and bypassing the operating system and the write process controlling writing operations to the second disk by the disk writing means which write process bypasses the operating system; and

controlling access to the rings and the list.

10. A file structure display method using a computer having an operating system, comprising:

reading disk contents using a disk reading means having a read process separate from and bypassing the operating system,

transforming, using a transforming means for taking the disk contents in a first file format with a first file format definition including a first directory structure and a first file structure and converting the contents into a second format with a second file format definition including a second directory structure and a second file structure, and

displaying, using a display means for displaying, file and directory names from a disk having files with file names stored in the first file format using the computer having the operating system which displays using the second file format.

11. A method as recited in claim 10, wherein said reading and displaying step includes echoing a file name and directory path to a user screen when a file or directory name from the disk is obtained.

12. A file display method using a computer having an operating system, comprising:

reading a file having contents from a disk using a disk reading means having a read process separate from and via bypassing the operating system, with the file contents having a first file format with a first file format definition including a first directory structure and a first file structure;

transforming, separate from and via bypassing the operating system, the file contents from the first file format to a second file format with a second file format definition including a second directory structure and a second file structure using the computer by maintaining a directory hierarchy of the first disk in the second format and converting record formats; and

displaying the file contents having the second file format used by the computer using a display means for displaying.

13. A method as recited in claim 12, wherein file contents are transformed before display.

14. A file format transform apparatus, comprising:

a disk drive having a disk; and

a computer having an operating system, connected to said drive and comprising transform means, separate from and bypassing the operating system, for transforming files on the disk from a first file format having a first file format definition including a first directory structure and a first file structure to a second file format having a second file format definition including a second directory structure and a second file structure by reading disk contents, transforming from the first file format to the second file format and writing format transformed contents onto the disk.

15. A file format transform apparatus, comprising:

a disk drive for accessing first and second disks; and

a computer having an operating system, connected to said drive and comprising transform means, separate from and bypassing the operating system, for transforming files on the first disk from a first file format to a second file format by reading first disk contents, transforming from the first file format to the second file format and writing format transformed contents onto the second disk and said transform means comprising;

means for determining, prior to the reading and during the transforming, the first file format from contents of the first disk; and

means for determining, prior to the writing and during the transforming, the second file format from contents of the second disk.

16. An apparatus as recited in claim 15, wherein said transform means further comprises:

means for storing, during the transforming, first disk directory contents on a source directory ring;

means for storing, during the transforming, first file contents on a source file ring;

means for creating, during the transforming, a two-dimensional list from the directory contents having a first dimension coordinating a first directory structure of the first disk and having a second dimension coordinating a second directory structure of the second disk;

means for designating, during the transforming, the contents of the source file ring as a destination file contents ring; and

means for storing, during the transforming, second directory contents on a destination directory ring responsive to the two-dimensional list for maintaining correct directory order.

17. An apparatus as recited in claim 16, wherein said transform means further comprises means for creating headers for files and directories of the second disk.

18. An apparatus as recited in claim 17, wherein said apparatus has a destination file contents ring and said transform means further comprises means for moving the file contents from the source file contents ring to the destination file contents ring and translating the file contents from the first format to the second format during the moving.

19. An apparatus as recited in claim 18, wherein said transform means further comprises means for controlling, during the transforming, access to the rings and the list.

20. An apparatus as recited in claim 18, wherein said process control means selectively activates said means responsive to the file format of the first and second disks.

21. A file format transform apparatus, comprising:

a disk drive having a disk; and

a computer having an operating system, connected to said disk drive and comprising transform means, separate from and bypassing the operating system, for transforming files on the disk from a first file format to a second file format by reading disk contents, transforming from the first file format to the second file format and writing format transformed contents onto the disk, and said transform means comprises;

source file look-up means for determining the location of files on the first disk;

source directory location means for determining the location of directories of the files on the first disk;

source block reading means for reading blocks from the first disk and storing files of the blocks on the source data ring and directories of the files on a source directory ring;

source directory search means for creating file and directory entries in a file description listing from the directories on the source directory ring;

translate means for translating the files on the source data ring from the first file format into the second file format and storing the files on a destination data ring;

destination directory location means for locating directories on a second disk;

header build means for building headers for files and directories listed on the file description list;

destination directory build means for building directories from the entries on the file description list and directories on the second disk and storing the directories on a destination directory out ring;

destination block write means for writing files from the destination data ring, directories from the out ring and headers onto the second disk in the second file format;

destination directory create means for creating directories on the second disk;

buffer control means for controlling access to the list and rings; and

process control means for controlling execution sequence of the above-listed means.

22. A file transfer system, comprising:

file storage means for storing files; and

a computer connected to said file storage means and transferring files within said storage means responsive to a two-dimensional file description list storing file and directory build order for the files of said file storage means and for maintaining correct directory order during the transferring, and said file storage means including a destination disk and said computer further including;

a source data ring storing files during the transferring and listed in said list;

a source directory ring storing directories during the transferring and listed in said list; and

a directory out ring storing directories during the transferring and listed in said list and from the said destination disk.

23. A system as recited in claim 22, said computer further including a destination data ring storing files during the transferring and listed in said list.

24. A system as recited in claim 23, said computer further including:

a source location window storing location information for the files during the transferring and listed in said list; and

a destination location window storing location information for the files listed in said list and files from said destination disk during the transferring.

25. A system as recited in claim 24, further comprising:

an allocation control list window storing indicators of allocated space on said destination disk during the transferring; and

an index control list window storing indicators of indexes allocated on said destination disk during the transferring.

26. A disk file transfer system, comprising:

file storage means for storing files and comprising a source disk and a destination disk; and

a computer connected to said file storage means and including;

a two-dimensional file description list storing file and directory entries in source disk directory structure hierarchical order and destination disk directory build order during a transfer;

a source data ring storing files listed in said list from the source disk during the transfer;

a source directory ring storing directories listed in said list from the source disk during the transfer;

a destination data out ring storing translated contents of said source data ring during the transfer;

a directory out ring storing directories listed in said list and from a destination disk during the transfer;

a source location window storing source disk location information for the files listed in said list during the transfer;

a destination location window storing location information for the files listed in said list and files from the destination disk during the transfer;

an allocation control list window storing indicators of allocated space on the destination disk during the transfer; and

an index control list window storing indicators of indexes allocated on the destination disk during the transfer.