FILE INDEX, METADATA STORAGE, AND FILE SYSTEM MANAGEMENT FOR MAGNETIC TAPE

• US 20110238716A1
• Filed: 03/25/2010
• Published: 09/29/2011
• Est. Priority Date: 03/25/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Richter, Rainer, Amir, Arnon, Pease, David A.
• Granted Patent: US 9,430,155 B2
• Time in Patent Office: Days
• US Class Current: 707/823
• CPC Class Codes: G06F 16/1727 Details of free space management performed by the file system saving storage space on storage systems G06F3/0608; management of blocks in storage devices G06F3/064
• CPC Class Codes: G06F 16/1873 Versioning file systems, temporal file systems, e.g. file system supporting different historic versions of files
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G06F 3/0682 Tape device
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox
• CPC Class Codes: G11B 27/032 on tapes G11B27/036, G11B27/038 take precedence

Abstract

In one embodiment, a method for writing data to a magnetic recording tape includes writing a plurality of files to a first partition of a magnetic recording tape using a tape drive, and writing an index to a second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape.

Claims

1. A method for writing data to a magnetic recording tape, the method comprising:

writing a plurality of files to a first partition of a magnetic recording tape using a tape drive; and

writing an index to a second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape.

2. The method of claim 1, wherein the information about the plurality of files includes additional file system attributes of the plurality of files.

3. The method of claim 2, wherein at least some of the attributes are settable by a user.

4. The method of claim 3, wherein the attributes include extended attributes that are definable and settable by a user.

5. The method of claim 1, further comprising writing a plurality of files to a third partition of a magnetic recording tape using a tape drive, and writing an index to the second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first and third partitions.

6. The method of claim 1, wherein the index includes a hierarchical directory and structure of references to the plurality of files.

7. The method of claim 1, further comprising storing a redundant copy of the index in the second partition.

8. The method of claim 1, further comprising storing a redundant copy of the index in the first partition.

9. The method of claim 1, further comprising writing an updated version of the index to the second partition upon updating at least one of the plurality of files, the updating the at least one of the plurality of files including appending data to the plurality of files in the first partition.

10. The method of claim 9, further comprising storing a version of the index in the second partition as the index existed prior to the updating thereof, and accessing the version of the index as it existed prior to the updating thereof for retrieving one of the files or portion thereof that is not present in the updated index.

11. The method of claim 10, further comprising rolling back a last update of the file content in the first data partition and changes to the index in the second data partition if the storing of at least one of the file content and index was interrupted.

12. The method of claim 1, wherein the partitions are physically separate and independently addressable on the magnetic recording tape.

13. The method of claim 1, further comprising at least one of saving and caching a copy of the index on a secondary storage system.

14. A computer program product for writing data to a magnetic recording tape, the computer program product comprising:

a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising;

computer readable program code configured to write a plurality of files to a first partition of a magnetic recording tape using a tape drive; and

computer readable program code configured to write an index to a second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape.

15. A method, comprising:

storing file content in a first data partition of a magnetic recording tape using a tape drive;

storing an index in a second data partition of the magnetic recording tape using the tape drive, the index comprising file content indexing information; and

retrieving a desired portion of file content stored in the first data partition by providing direct access to arbitrary locations of the file content using the indexing information.

16. A method for formatting a tape, comprising:

formatting a first partition and a second partition on a tape using a tape drive; and

writing an initial index to the second partition.

17. The method of claim 16, further comprising creating a plurality of copies of the initial index and storing the copies in one of the partitions.

18. The method of claim 16, further comprising creating a plurality of label blocks at the beginning of at least one of the partitions.

19. A method, comprising:

storing file content in a first data partition of a magnetic recording tape using a tape drive;

storing an index in a second data partition of the magnetic recording tape using the tape drive, the index comprising file content indexing information; and

updating the file content stored in the first data partition by appending new content to the file content and updating the index stored in the second data partition by writing an updated version of the index.

20. The method of claim 19, wherein the new content is appended at an end of the file content in the first data partition, and wherein the index is updated to reflect the updating by modifying an extents list of the file content by removing portions of extents deleted by the file modification and adding new extents to the extents list.

21. The method of claim 19, further comprising rolling back a last update of the file content in the first data partition and changes to the index in the second data partition if the storing of at least one of the file content and index was interrupted.

22. The method of claim 19, wherein the index includes a hierarchical directory structure, wherein the hierarchical directory structure includes references to the file content organized in a plurality of directories;

and further comprising outputting the hierarchical directory structure for display.

23. The method of claim 19, further comprising storing metadata of the file content stored in the first data partition in the second data partition, wherein the metadata is selected from a group consisting of standard file attributes, extended file attributes, metadata files, previews, and search indices.

24. The method of claim 19, wherein the indexing information of file content that has been updated is deleted from the index without rewriting the first partition;

and further comprising generating and storing a search index in the second data partition by analyzing and indexing the file content stored in the first data partition, wherein the search index allows access when loading the magnetic recording tape, wherein the search index is updated when data is appended to the file content stored on the first data partition.

25. A method for reading data from a magnetic recording tape having at least two partitions, the method comprising:

reading an index stored on a first partition of a magnetic recording tape using a tape drive;

finding locations of a plurality of file portions on the magnetic recording tape using the index; and

reading the file portions from a second partition of the magnetic tape using the tape drive.