METHOD AND A STORAGE SERVER FOR DATA REDUNDANCY

• US 20120173925A1
• Filed: 09/15/2010
• Published: 07/05/2012
• Est. Priority Date: 09/16/2009
• Status: Active Grant

• Current Assignee: Varaani Works Oy
• Original Assignee: Varaani Works Oy
• Inventors: Lahdensivu, Kimmo
• Granted Patent: US 8,954,793 B2
• Time in Patent Office: Days
• US Class Current: 714/15
• CPC Class Codes: G06F 11/1008 in individual solid state devices G06F11/1004 takes precedence
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A method and a storage server for backing up data involves mass storage devices of users of the service that connect to the storage server of the service provider over a public data network. The customers store the data with their terminals. The data is stored to the file system of the mass storage device which encrypts the stored data and transfers the data in encrypted form over the public data network to the storage server. The storage server calculates error correction data from the encrypted data. The error correction data is stored in the mass memory of the storage server. When recovering the stored data of the users, the storage server requests the stored data of all the users whose data was used for the error correction data calculation over the public data network to be used for the recovery calculation.

Claims

1. A method for data redundancy using a data network (1) to transfer the data to be backed up to a remote service (2), comprising of the data to be backed up (3.1) and the stored information of other users of the service (5) that are used to calculate error correction data (2.3) that is used to recover the original stored information (3.1) by calculating the original backed up data from the other users'"'"' data (5) and the error correction data (2.3).

2. The method of claim 1, wherein the error correction data (2.3) is stored in the storage server (2) of the service provider.

3. The method of claim 1, wherein the error correction data (2.3) is stored in the mass storage devices (5) of such users that are not part of the group, whose stored data was used to calculate the error correction data.

4. The methods of any claims 1-3, wherein the data to be backed up (3.1) is encrypted (3.3) before transfer to the service, the error correction data (2.3) is calculated from the encrypted data and the data is recovered to encrypted form.

5. The methods of any claims 1-4, wherein an error correction algorithm that enables recovery of the stored information, even if more than one data set used for the calculation is missing, is used for the error correction data calculation (2.1).

6. The methods of any claims 1-5, wherein the data to be backed up is split into pieces, each having the related error correction data (2.3) calculated with the stored data (5) of different users of the service.

7. The method of claim 6, wherein the error correction data (2.3) for a specific portion the data to be backed up (3.1) is calculated (2.1) with the stored data of the users, whose data is not used for calculating error correction data (2.3) for any other portion of the same user.

8. The methods of any claims 1-7, wherein the error correction data (2.3) is calculated again when the stored data (3.1) changes using a method where the new error correction data (2.3) can be calculated based on the changed data and the prior error correction data.

9. The method of claim 8, wherein the data is stored to a file system (3.2), the state of the file system (3.2) can be saved at any moment of time, the state can be recovered later and the difference between the saved state and the later state can be used to identify the changes in the stored data.

10. The methods of any claims 8-9, wherein the file system (3.2) is in a mass storage device (3) that has moving components that produce noise, the changed data is copied to a silicon-based memory (3.4) in the same device from where the changed data is transferred to the service (2).

11. The methods of any claims 1-10, wherein the users, whose data belongs to the same group used for calculating the error correction data (2.3), are selected based on the risk analysis of the user, the characteristics of the mass storage device (3) or characteristics of the network connection of the user.

12. The method of claim 11, wherein the user is attached to the service (2) so that the data to be backed up (3.1) is copied to the service (2) and the usage information of the user is used for creating the risk analysis.

13. The methods of any claims 1-10, wherein the size of the group used for error correction data calculation (2.1) is determined based on the risk analysis of the user, the characteristics of the mass storage device (3) used for storing the data, the characteristics of the data network connection of the user, the type of the stored data (3.1) or the user selected service level.

14. The methods of any claims 1-13, wherein the stored data (3.1) of the user is unavailable for specified time period, the data recovery (2.4) is initiated automatically by the service (2).

15. The method of claim 14, wherein the stored data (3.1) of the user is unavailable for specified time period, the user'"'"'s data is removed from the group used for calculating the error correction data (2.1).

16. The methods of any claims 1-15, wherein the stored data (3.1) metadata is copied to the service (2) separately and the metadata is used to prioritise the recovery order of the recovered data.

17. The methods of any claims 1-16, wherein a checksum is calculated from the stored data that is used for the error correction data calculation (2.1). The checksum is used to verify that the changed data sent by the user'"'"'s mass storage device (3) represents the change relative to the same data that was used to calculate the error correction data used for the previous calculation.

18. A storage server for backing up data using a data network (1) to transfer the data to be backed up from the customers'"'"' mass storage devices (3, 5) comprising of the data to be backed up (3.1) and the stored information of other users of the service (5) that are used to calculate error correction data (2.3) that is used to recover the original stored information (3.1) by calculating the original backed up data from the other users'"'"' data (5) and the error correction data (2.3).

19. A storage server of claim 18, wherein the error correction data (2.3) is stored in the storage server (2) of the service provider.

20. A storage server of any claims 18-19, wherein the data to be backed up is split into pieces, each having the related error correction data (2.3) calculated with the stored data (5) of different users of the service.

21. A storage server of claim 20, wherein the error correction data (2.3) for a specific portion the data to be backed up (3.1) is calculated (2.1) with the stored data of the users, whose data is not used for calculating error correction data (2.3) for any other portion of the same user.