Data repository and method for promoting network storage of data

• US 20050131961A1
• Filed: 10/14/2004
• Published: 06/16/2005
• Est. Priority Date: 02/18/2000
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Permabit Technology Corporation (International Business Machines Corporation)
• Inventors: Margolus, Norman H., Homsy, George E. II, Floyd, Jered J., Knight, Thomas F. Jr.
• Granted Patent: US 7,685,096 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/137 Hash-based content-based indexing of textual data G06F16/31
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/60 Protecting data
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/6272 by registering files or documents with a third party
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 21/645 using a third party
• CPC Class Codes: Y10S 707/959 Network
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A method for turning variable-length file path names into fixed-length object identifiers in a data repository, the method comprising, assigning a fixed-value identifier to a file system in the data repository, computing a first deterministic pseudo-random function that combines a first component of a plurality of file system pathname components associated with a file with the fixed-value identifier, computing a second determininstic pseudo-random function that combines a second component of the plurality of file system pathname components with the result of the first function, and using at least one of the computed deterministic pseudo-random functions to produce a fixed-length object identifier for the file.

Claims

1. A method for turning variable-length file path names into fixed-length object identifiers in a data repository, the method comprising,

assigning a fixed-value identifier to a file system in the data repository;

computing a first deterministic pseudo-random function that combines a first component of a plurality of file system pathname components associated with a file with the fixed-value identifier;

computing a second determininstic pseudo-random function that combines a second component of the plurality of file system pathname components with the result of the first function; and

using at least one of the computed deterministic pseudo-random functions to produce a fixed-length object identifier for the file.

2. The method of claim 1 further comprising computing a final deterministic pseudo-random function that combines the last component of the plurality of file system pathname components with the result of the penultimate deterministic pseudo-random function and using the final deterministic pseudo-random function to produce the fixed length object identifier for the file.

3. The method of claim 1 in which at least one deterministic pseudo-random function comprises a cryptographic hash function.

4. The method of claim 1 in which the fixed-value identifier assigned to the file system in the data repository is chosen randomly.

5. The method of claim 1 in which the value of the identifier depends on information descriptive of the file system or network identity information about a file server.

6. The method of claim 1 in which the pathname information is stored in the data repository.

7. The method of claim 6 in which a program which is a client of the data repository uses the object identifier for a directory object containing the name of a file in order to construct an object identifier for the file.

8. The method of claim 7 in which a credential, authorizing access to the file named within the directory object, contains information about the object identifier of the directory object, and wherein the credential contains no information about the object identifier of the file named within the directory object.

9. The method of claim 8 in which the credential is used to transmit access to the files contained in the directory from one client program to another.

10. The method of claim 1 in which a client program copies files from a source file system into the data repository using source path names to derive repository object identifiers.

11. The method of claim 1 in which the data repository uses a fingerprint of object content in order to identify and locate a block of content.

12. The method of claim 11 in which the fingerprint is a cryptographic hash of the block of content.

13. The method of claim 11 in which a block of content which is already stored within the repository is relied upon by a deposit of an object that contains the identical block of content, rather than storing a separate copy of the identical block of content.

14. The method of claim 1 wherein the fixed-value identifier comprises a name-randomizer value.