File portion logging and arching by means of an auxilary database

• US 5,617,566 A
• Filed: 12/15/1994
• Issued: 04/01/1997
• Est. Priority Date: 12/10/1993
• Status: Expired due to Term

• Current Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Original Assignee: Cheyenne Advanced Technology Limited
• Inventors: Malcolm, Peter B.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Lintz, Paul R.
• Application Number:
  US08/356,478
• Time in Patent Office: 838 Days
• Field of Search: 395/600, 395/575, 395/800, 395/444, 395/460
• US Class Current: 707/662
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 2201/80 Database-specific techniques
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

In a hierarchical storage management system, files are automatically archived when they have not been accessed for a specified period. With large database files, the file cannot be archived, even though only a small number of records has been used. In this invention an auxiliary database is maintained indicating which data blocks have been accessed and on what dates. Non-accessed blocks and then be archived and deleted from the disk file to reduce storage requirements.

Claims

1. A method of accessing data stored in a computer system that includes a random access memory, a central processing unit, and mass storage means, the method comprising the steps of:

providing instructions stored in said random access memory to said central processing unit to cause said processing unit to seek to access data stored in said mass storage means by generating a write request or a read request;

said central processing unit commanding the following operations;

identifying a file to which access is required;

identifying from said write request or read request file portion locations in said file to which access is necessary;

building an auxiliary database which identifies said file portion locations to which access is to be made and the date or date/time at which access is made; and

accessing said file portions.

2. A method as claimed in claim 1, in which said computer system comprises a file allocation table which defines the locations of file portions on said mass storage means, the method further comprising the step of checking said file allocation table to determine whether said file portions are on said mass storage device.

3. A method as claimed in claim 2, in which said computer system comprises secondary storage means for storing archived files, the method further comprising, when said checking step determines that said file portions are not on said mass storage device, the step of retrieving said file portions from said secondary storage means.

4. A method as claimed in claim 2, in which said file portions are blocks corresponding to the elemental blocks identified in said file allocation table.

5. A method as claimed in claim 1, in which said auxiliary database further defines whether said access is a write access or a read access.

6. A method of archiving data stored in a computer system that includes a random access memory, a central processing unit, mass storage means, and secondary storage means, the method comprising the steps of:

providing instructions stored in said random access memory to said central processing unit to cause said central processing unit to archive selected data stored in said mass storage means onto said secondary storage means to release space on said mass storage means;

said central processing unit commanding the following operations;

providing in relation to a file to be archived an auxiliary database which identifies file portion locations in said file to which access has been made and the date or date/time at which accesses were made;

identifying from said auxiliary database file portion locations that have been accessed since a specified date and file portion locations that have not been accessed since said specified date;

archiving to said secondary storage means at least some file portions identified in said auxiliary database by file portion locations that have not been accessed since said specified date; and

deleting from said mass storage means file portions that have not been accessed since said specified date, while retaining on said mass storage means file portions that have been accessed since said specified date.

7. A method as claimed in claim 6, in which said archiving and deleting steps comprise archiving and deleting those file portions that have not been accessed since said specified date and have already been backed up a predetermined number of times.

8. A method as claimed in claim 6, in which said computer system comprises a file allocation table which defines the locations of file portions on said mass storage means, and in which the deleting step comprises amending said file allocation table.

9. A method as claimed in claim 8, in which said file portions are blocks corresponding to the elemental blocks identified in said file allocation table.

10. A method of accessing data stored in a computer system that includes a random access memory, a central processing unit, and mass storage means, the method comprising the steps of:

providing instructions stored in said random access memory to said central processing unit to cause said processing unit to seek to access data stored in said mass storage means by generating a read request;

said central processing unit commanding the following operations;

identifying a file to which read access is required;

identifying file portions in said file to which access is necessary;

building an auxiliary database which identifies said file portions to which access is to be made by at least file portion location, and not including the file portion itself; and

accessing said file portions.

11. A method as claimed in claim 10, in which said computer system comprises a file allocation table which defines the locations of file portions on said mass storage means, the method further comprising the step of checking said file allocation table to determine whether said file portions are on said mass storage device.

12. A method as claimed in claim 11, in which said computer system comprises secondary storage means for storing archived files, the method further comprising, when said checking step determines that said file portions are not on said mass storage device, the step of retrieving said file portions from said secondary storage means.

13. A method as claimed in claim 11, in which said file portions are blocks corresponding to the elemental blocks identified in said file allocation table.

14. A method of archiving data stored in a computer system that includes a random access memory, a central processing unit, mass storage means, and secondary storage means, the method comprising the steps of:

providing instructions stored in said random access memory to said central processing unit to cause said central processing unit to archive selected data stored in said mass storage means onto said secondary storage means to release space on said mass storage means;

said central processing unit commanding the following operations;

providing in relation to a file to be archived an auxiliary database which identifies file portion locations in said file to which access has been made;

identifying from said auxiliary database file portion locations that have been accessed;

archiving to said secondary storage means at least some file portions that have not been accessed; and

deleting from said mass storage means file portions that have not been accessed, while retaining on said mass storage means file portions that have been accessed.

15. A method as claimed in claim 14, in which said archiving and deleting steps comprise archiving and deleting those file portions that have not been accessed and have already been backed up a predetermined number of times.

16. A method as claimed in claim 14, in which said computer system comprises a file allocation table which defines the locations of file portions on said mass storage means, and in which the deleting step comprises amending said file allocation table.

17. A method as claimed in claim 16, in which said file portions are blocks corresponding to the elemental blocks identified in said file allocation table.

18. In a computer system that includes a random access memory, a central processing unit, and mass storage means, apparatus for accessing data stored in said computer system, said apparatus comprising:

means for providing instructions stored in said random access memory to said central processing unit to cause said processing unit to seek to access data stored in said mass storage means by generating a write request or a read request;

means for identifying a file to which access is required;

means for identifying file portion locations in said file to which access is necessary;

means for building an auxiliary database which identifies said file portion locations to which access is to be made and the date or date/time at which access is made; and

means for accessing said file portions.

19. The apparatus as claimed in claim 18, in which said computer system comprises a file allocation table which defines the locations of file portions on said mass storage means, the apparatus further comprising means for checking said file allocation table to determine whether said file portions are on said mass storage device.

20. The apparatus as claimed in claim 19, in which said computer system comprises secondary storage means for storing archived files, and means for retrieving said file portions from said secondary storage means when said checking step determines that said file portions are not on said mass storage device.

21. The apparatus as claimed in claim 19, in which said file portions are blocks corresponding to the elemental blocks identified in said file allocation table.

22. The apparatus as claimed in claim 18, in which said auxiliary database further defines whether said access is a write access or a read access.

23. In a computer system that includes a random access memory, a central processing unit, mass storage means, and secondary storage means, apparatus for archiving data stored in said computer system, said apparatus comprising:

means for providing instructions stored in said random access memory to said central processing unit to cause said central processing unit to archive selected data stored in said mass storage means onto said secondary storage means to release space on said mass storage means;

means for providing in relation to a file to be archived an auxiliary database which identifies file portion locations in said file to which access has been made and the date or date/time at which accesses was made;

means for identifying from said auxiliary database file portion locations that have been accessed since a specified date and file portion locations that have not been accessed since said specified date;

means for archiving to said secondary storage means at least some file portions that have not been accessed since said specified date; and

means for deleting from said mass storage means file portions that have not been accessed since said specified date, while retaining on said mass storage means file portions that have been accessed since said specified date.

24. The apparatus as claimed in claim 23, in which said archiving means and said deleting means comprise means for archiving and deleting those file portions that have not been accessed since said specified date and have already been backed up a predetermined number of times.

25. The apparatus as claimed in claim 23, in which said computer system comprises a file allocation table which defines the locations of file portions on said mass storage means, and in which the deleting means comprises means for amending said file allocation table.

26. The apparatus as claimed in claim 25, in which said file portions are blocks corresponding to the elemental blocks identified in said file allocation table.

27. In a computer system that includes a random access memory, a central processing unit, and mass storage means, apparatus for archiving data stored in said computer system, said apparatus comprising:

means for providing instructions stored in said random access memory to said central processing unit to cause said processing unit to seek to access data stored in said mass storage means by generating a read request;

means for identifying a file to which read access is required;

means for identifying file portion locations in said file to which access is necessary;

means for building an auxiliary database which identifies said file portion locations to which access is to be made; and

means for accessing said file portions.

28. The apparatus as claimed in claim 27, in which said computer system comprises a file allocation table which defines the locations of file portions on said mass storage means, the apparatus further comprising means for checking said file allocation table to determine whether said file portions are on said mass storage device.

29. The apparatus as claimed in claim 28, in which said computer system comprises secondary storage means for storing archived files, and means for retrieving said file portions from said secondary storage means when said checking step determines that said file portions are not on said mass storage device.

30. The apparatus as claimed in claim 28, in which said file portions are blocks corresponding to the elemental blocks identified in said file allocation table.

31. In a computer system that includes a random access memory, a central processing unit, mass storage means, and secondary storage means, apparatus for archiving data stored in said computer system, said apparatus comprising:

means for providing instructions stored in said random access memory to said central processing unit to cause said central processing unit to archive selected data stored in said mass storage means onto said secondary storage means to release space on said mass storage means;

means for providing in relation to a file to be archived an auxiliary database which identifies file portion locations in said file to which access has been made;

means for identifying from said auxiliary database file portion locations that have been accessed;

means for archiving to said secondary storage means at least some file portions that have not been accessed; and

means for deleting from said mass storage means file portions that have not been accessed, while retaining on said mass storage means file portions that have been accessed.

32. The apparatus as claimed in claim 31, in which said archiving and deleting means comprise means for archiving and deleting those file portions that have not been accessed and have already been backed up a predetermined number of times.

33. The apparatus as claimed in claim 31, in which said computer system comprises a file allocation table which defines the locations of file portions on said mass storage means, and in which the deleting means comprises means for amending said file allocation table.

34. The apparatus as claimed in claim 33, in which said file portions are blocks corresponding to the elemental blocks identified in said file allocation table.