Distributive storage controller and method

• US 20040049700A1
• Filed: 03/06/2003
• Published: 03/11/2004
• Est. Priority Date: 09/11/2002
• Status: Active Grant

• Current Assignee: Fujifilm Business Innovation Corp. (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Yoshida, Takeo
• Granted Patent: US 7,337,331 B2
• Time in Patent Office: Days
• US Class Current: 713/201
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• 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 2221/2107 File encryption
• CPC Class Codes: H04L 63/04 for providing a confidential data exchange among entities communicating through data packet networks

Abstract

An inexpensive data storage technique utilizing available capacity in individual computer devices connected to a network is provided. When a backup client (BC) (14) of a user PC receives a backup instruction for a file from a user, the backup client (14) requests backup to a backup control server (20). The backup control server (20) divides and encrypts the file to be backed up into a plurality of encrypted pieces, transfers the encrypted pieces to user PCs (10), and stores the encrypted piece in the HDDs (12) of the user PCs (10). When the destributively backed up file is to be extracted, the user PC 10 obtains each encrypted piece from the user PCs 10 on which they are stored, and combines and decrypts the encrypted pieces to restore the original file.

Claims

1. A distributive storage controller for providing a data storage service to a plurality of computer devices connected to a network, the controller comprising:

a storage controller which, upon receiving a storage instruction of data from one of the computer devices, checks the status of a storage device of each of the computer devices, divides and encrypts the data into a plurality of encrypted pieces, selects, for each encrypted piece, a computer device on which the piece is to be stored from among the plurality of computer devices based on the result of the checking, transfers and stores the encrypted pieces to selected corresponding computer devices, and generates storage location information indicating which encrypted piece is stored in which computer device; and

an extraction controller which, upon receiving an extraction instruction of data from one of the computer devices, identifies each computer device to which each of the encrypted pieces for the data is stored referring to the storage location information, obtains each encrypted piece from the computer device, restores the original data based on the encrypted pieces, and provides the restored data to the computer device instructing the extraction.

2. A distributive storage controller according to claim 1, wherein

during the division and encryption, the storage controller removes a portion of each divided piece of data, generates the encrypted pieces from the segment remaining after the removal, and stores data of fragment which is removed from each piece to a predetermined storage location on the network, and

the extraction controller obtains the data of fragment from the predetermined storage location, integrates the group of encrypted pieces obtained from the computer devices and the data of fragment, and restores the original data.

3. A distributive storage controller according to claim 1, wherein

the storage controller has location information indicating the physical location of each of the computer devices and selects a computer devices as a storage location of each of the encrypted pieces based on the location information in such a manner that the storage locations are physically separated.

4. A distributive storage controller according to claim 1, wherein

the storage controller, upon receiving from one of the computer devices of a request for transferring the encrypted piece, checks the status of storage devices of the other computer devices, selects a computer device as a transfer destination to which the piece is to be stored from among the other computer devices based on the result of the checking, transfers the encrypted piece from the computer device requesting transfer to the transfer destination computer device, and corrects the storage location information of the data corresponding to the encrypted piece according to the transfer.

5. A distributive storage controller according to claim 1, wherein the distributive storage controller is incorporated into one of the plurality of computer devices.

6. A distributive storage controller according to claim 5, further comprising:

a local storage controller which, upon receiving a storage instruction of a file from a program executed on the computer device on which the distributive storage controller is incorporated, stores a predetermined portion of the file to the storage device of the computer device and issues a storage instruction for the remaining portion as the data to be stored to the storage controller; and

a local extraction controller which, upon receiving a read instruction of a file which has been stored by the local storage, controller from a program executed on the computer device on which the distributive storage controller is incorporated, reads a predetermined portion of the file from the storage device of the computer device, supplies the read portion to the program, issues an extraction instruction for the stored data corresponding to the remaining portion to the extraction controller, and supplies the stored data restored by the extraction controller in response to the extraction instruction to the program.

7. A distributive storage controller according to claim 6, wherein

while the local extraction controller is reading the predetermined portion from the storage device and supplying the portion to the program, the extraction controller restores the stored data corresponding to the remaining portion.

8. A computer device connected to a network, the computer device comprising;

a response module for returning a response including information on available capacity of a storage device of the computer device in response to a status inquiry received from a requesting device via the network;

a storage module for storing data transmitted from the requesting device via the network to the storage device; and

a data provider which, in response to a data extraction request sent from the requesting device via the network, reads data related to the extraction request from the storage device and transmits the data to the requesting device.

9. A computer device according to claim 8, further comprising

a storage monitor for monitoring the available capacity of the storage device, determining whether or not the available capacity is sufficient, and issuing a transfer request for stored encrypted piece to the requesting device when determining that the available capacity of the storage device is insufficient.

10. A distributive storage system comprising:

a plurality of computer devices connected to a network;

a storage controller which is connected to the network and which, upon receiving a storage instruction of data from a client device, checks the status of a storage device of each of the computer devices, divides and encrypts the data into a plurality of encrypted pieces, selects, for each encrypted piece, a computer device to which the piece is to be stored from among the plurality of computer devices based on the result of the checking, transfers and stores each of the encrypted pieces to the selected corresponding computer device, and generates storage location information indicating which encrypted piece is stored in which computer device; and

an extraction controller which is connected to the network and which, upon receiving an extraction instruction of data from a client device, identifies computer devices to which the encrypted pieces of the data are stored by referring to the storage location information, obtains each encrypted piece from the corresponding computer device, restores the original data based on the encrypted pieces, and supplies the restored data to the client device.

11. A system according to claim 10, wherein

each of the computer devices comprises a power supply controller for supplying power to in response to an activation instruction via the network;

and

the extraction controller comprises an activation controller for transmitting an activation instruction, when there is a computer device in which the power is switched off from among the computer devices identified from the storage location information, to the power supply controller of each of the computer devices in which the power is switched off.

12. A system according to claim 10, wherein

the computer device monitors the available capacity of the storage device, determines whether or not the available capacity is sufficient, and, when determining that the available capacity is insufficient, issues a transfer request for the stored encrypted piece to the storage controller;

and

the storage controller, upon receiving a transfer request of the encrypted piece from the computer device, checks the status of the storage device of each of the other computer devices, selects a computer device as a transfer destination to which the piece is to be stored from among the other computer devices based on the results of the checking process, transfers the encrypted piece from the computer device issuing the transfer request to the transfer destination computer device, and corrects the storage location information of the data corresponding to the encrypted piece according to the transfer.

13. A system according to claim 10, wherein

the storage controller and the extraction controller are incorporated into at least one of the plurality of computer devices.

14. A method for controlling a distributive storage which provides a data storage service to a plurality of computer devices connected to a network, the method comprising the steps of:

(a) upon reception of a storage instruction of data, checking the status of a storage device of each of the computer devices, dividing and encrypting the data into a plurality of encrypted pieces, selecting, for each encrypted piece, a computer device on which the piece is to be stored from among the plurality of computer devices based on the result of the checking process, transferring and storing each encrypted piece to the selected corresponding computer device, and generating storage location information indicating which encrypted piece is stored in which computer device; and

(b) upon reception of an extraction instruction of data, identifying computer devices to which the encrypted pieces corresponding to the data are stored by referring to the storage location information, obtaining the encrypted piece from each of the computer devices, and restoring the original data based on the encrypted pieces.

15. A method according to claim 14, wherein

the step (a) comprises, in the dividing and encrypting process, substeps of removing a portion of each piece obtained by dividing the data, generating the encrypted pieces from the segments remaining after the removal process, and storing data of the fragments removed from the pieces to a predetermined storage location on the network, and

the step (b) comprises substeps of obtaining the data of the fragments from the predetermined storage location and restoring the original data after integrating the group of encrypted pieces obtained from the computer devices and the data of the fragments.

16. A method according to claim 14, wherein

the step (a) comprises a substep of selecting, based on location information indicating the physical locations of the computer devices, computer devices as the storage locations for the encrypted pieces so that the storage destination computer devices are physically separated.

17. A method according to claim 14, further comprising the step of:

upon receiving a transfer request for the encrypted piece from any of the computer devices, checking the status of the storage device of each of the other computer devices, selecting a compute device as a transfer destination to which the piece is to be stored from among the other computer devices based on the result of the checking process, transferring the encrypted piece from the computer device issuing the transfer request to the transfer destination computer device, and correcting the storage location information for the data corresponding to the encrypted piece according to the transfer.

18. A method for controlling a computer device which is connected to a network and provided for a distributive storage service of data, the method comprising the steps of:

returning a response including information of the available capacity of a storage device in the computer device in response to a status inquiry sent from a requesting device via the network;

storing data transmitted from the requesting device via the network to the storage device; and

in response to a data extraction request sent from the requesting device via the network, reading the data related to the extraction request from the storage device and transmitting the data to the requesting device.

19. A method according to claim 18, further comprising the step of:

monitoring the available capacity of the storage device, determining whether or not the available capacity is sufficient, and, upon determining that available capacity of the storage device is insufficient, issuing a transfer request of the stored encrypted piece to the requesting device.

20. A method for controlling a distributive storage system comprising a plurality of computer devices, a storage controller, and an extraction controller all of which are connected to a network, the method comprising the steps of:

(a) when the storage controller receives a storage instruction of data from a client device, checking the status of a storage device of each of the computer devices, dividing and encrypting the data into a plurality of encrypted pieces, selecting, for each encrypted piece, a computer device to which the piece is to be stored from among the plurality of computer devices based on the result of the checking process, transferring and storing the encrypted piece to the selected corresponding computer device, and generating storage location information indicating which encrypted piece is stored in which computer device; and

(b) when the extraction controller receives an extraction instruction of data from a client device, identifying computer devices to which the encrypted pieces corresponding to the data are stored by referring to the storage location information, obtaining each of the encrypted pieces from each computer device, restoring the original data based on the encrypted pieces, and supplying the restored data to the client device.

21. A method according to claim 20, wherein

when it is determined that the power of any of the computer devices from among the computer devices identified from the storage location information has is switched off, the extraction controller transmits an activation instruction to the computer device.

22. A method according to claim 20, wherein

the computer device monitors the available capacity of the storage device, determines whether or not the available capacity is sufficient, and upon determining that the available capacity of the storage device is insufficient, issues a transfer request for the stored encrypted piece to the storage controller;

the storage controller, upon receiving the transfer request for the encrypted piece from the computer device, checks the status of the storage device of each of the other computer devices, selects a computer device as a transfer destination to which the piece is to be stored from among the other computer devices based on the result of the checking process, transfers the encrypted piece from the computer device issuing the transfer request to the transfer destination computer device, and corrects the storage location information of the data corresponding to the encrypted piece according to the transfer.

23. A computer readable recording medium which records a program which, when executed, causes a computer system connected to a network to execute:

a storage control step of, when receiving a storage instruction of data, checking the status of a storage device of each of a predetermined plurality of computer devices on the network, dividing and encrypting the data into a plurality of encrypted pieces, selecting, for each encrypted piece, a computer device to which the piece is to be stored from among the plurality of computer devices based on the result of the checking process, transferring and storing the encrypted piece to the selected corresponding computer device, and generating storage location information indicating which encrypted piece is stored to which computer device; and

an extraction control step of, when receiving an extraction instruction for data, identifying computer devices to which the encrypted pieces for the data are stored by referring to the storage location information, obtaining the encrypted pieces from the computer devices, and restoring the original data based on the encrypted pieces.

24. A computer readable recording medium which records a program which, when executed, causes a computer system connected to a network to execute the steps of:

returning a response including information on the available capacity of a storage device within its own device in response to a status inquiry sent from a requesting device via the network;

storing data transmitted from the requesting device via the network to the storage device; and

in response to an extraction request of data sent from the requesting device via the network, reading the data related to the extraction request from the storage device and transmitting the data to the requesting device.