Redundancy for storage data structures

• US 20080010580A1
• Filed: 06/27/2005
• Published: 01/10/2008
• Est. Priority Date: 06/27/2005
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Anderson, David, Yang, Xueshi, Iren, Sami
• Granted Patent: US 7,533,330 B2
• Time in Patent Office: Days
• US Class Current: 714/763
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence
• CPC Class Codes: G11B 2220/2516 Hard disks

Abstract

A storage device comprising has a storage medium, a read-write mechanism, an object-based file system interface, and a controller. The read-write mechanism is adapted to read and to write data from and to the storage medium. The object-based file system interface within the storage device is adapted to organize and access data on the storage medium as objects and to access attributes of each data object. The controller is adapted to generate redundancy data for each data object to be stored on the storage medium according to the associated attributes and to store the data object and its associated redundancy data on the storage medium.

Claims

1. A storage device comprising:

a storage medium;

a read write mechanism adapted to read and write data objects from and to the storage medium;

an object-based file system interface within the storage device adapted to organize and access data on the storage medium as objects, the object-based file system interface adapted to access attributes associated with each data object; and

a controller adapted to control access to the storage medium through the read-write mechanism, the controller adapted to generate redundancy data for each data object to be stored on the storage medium according to the associated attributes and to store the data object and its associated redundancy data on the storage medium.

2. The storage device of claim 1 wherein the controller is adapted to apply a redundancy algorithm to each data object to generate its associated redundancy data.

3. The storage device of claim 1 wherein the controller further comprises:

a memory adapted to temporarily store changes to a stored data object when the stored data object is changed, wherein the controller is adapted to generate associated redundancy data based on changes to the data object.

4. The storage device of claim 1 wherein, each time a particular data object is accessed, the controller accesses the associated redundancy data for the particular data object, the controller adapted to use the accessed redundancy data to recover the data object if an error is detected.

5. The object-based storage device of claim 1 wherein the controller is adapted to apply different redundancy algorithms to a particular object and its sub-fields for a desired level of protection according to the associated attributes of the particular object.

6. The object-based storage device of claim 1 wherein the controller is adapted to select a redundancy algorithm from a plurality of redundancy algorithms and to generate the redundancy data according to the selected redundancy algorithm.

7. A storage device comprising:

a storage medium;

an object-based file system interface within the storage device adapted to access attributes of each data object and to derive information about contents of each data object from the accessed attributes, the object-based file system adapted to allocate space on the storage medium for data objects to be stored based on the derived information;

a read-write mechanism coupled to the storage medium adapted to read and write data objects from and to the allocated space on the storage medium; and

a controller adapted to determine a desired level of error protection for each data object based on the accessed attributes and to generate redundancy data for each data object to be stored on the storage medium according to the desired level of error protection.

8. The storage device of claim 7 wherein the data object and its associated redundancy data are stored on the storage medium as separate entities.

9. The storage device of claim 7 wherein the data object and its associated redundancy data are stored on the storage medium in one data structure.

10. The storage device of claim 7 further comprising:

a memory coupled to the controller and adapted to store a plurality of redundancy algorithms;

wherein the controller is adapted to select a redundancy algorithm from the plurality of redundancy algorithms based on the desired level of protection and to apply the selected redundancy algorithm to generate the associated redundancy data.

11. The storage device of claim 10 wherein the controller is adapted to select different redundancy algorithms with different levels of data protection for data objects and their sub-fields according to a desired level of protection.

12. The storage device of claim 7 wherein each time a data object is accessed, the controller is adapted to access and update its associated redundancy data.

13. The storage device of claim 7 wherein the storage device comprises a RAID storage system and wherein the associated redundancy data is stored across multiple discs of the RAID storage system.

14. A method for providing redundant protection for data objects stored on a storage device, the method comprising:

accessing attributes of each data object to be stored on a storage medium of the object-based storage device using an object-based file system interface within the storage device;

generating redundancy data from the data object according to a desired level of error protection and reliability based on the accessed attributes of the data object;

allocating space for the data object and for the generated redundancy data on the storage medium using the object-based file system interface; and

writing the data object and the generated redundancy data to the allocated space on the storage medium using a read-write mechanism of the storage device.

15. The method of claim 14 further comprising:

accessing the redundancy data each time the data object is accessed.

16. The method of claim 14 wherein before the step of generating, the method further comprises:

determining a desired level of protection for the data object based on the accessed attributes of the data object; and

selecting a redundancy algorithm from a plurality of redundancy algorithms based on the desired level of protection.

17. The method of claim 14 wherein if the stored data object is later retrieved and modified, the method further comprising:

calculating modified redundancy data for the modified data object; and

storing the modified data object and the modified redundancy data on the storage medium.

18. The method of claim 14 wherein the step of generating comprises:

applying selected redundancy algorithms for desired error protection and reliability to the data object and its sub-elements according to the attributes of the data object.

19. The method of claim 14 wherein the data object and its associated redundancy data are written as separate entities or as one file structure.

20. The method of claim 14 wherein the redundancy data provides a level of protection based on the logical boundary of each data object.