SECURELY DELETING DATA IN A TRANSACTIONALLY CONSISTENT MANNER

• US 20080177802A1
• Filed: 01/23/2007
• Published: 07/24/2008
• Est. Priority Date: 01/23/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Haye, Mark A., Anglin, Matthew J., Cannon, David M.
• Granted Patent: US 8,352,448 B2
• Time in Patent Office: Days
• US Class Current: 707/202
• CPC Class Codes: G06F 11/1441 Resetting or repowering
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1474 in transactions G06F16/20 takes precedence
• CPC Class Codes: G06F 21/1088 by using transactions with atomicity, consistency, or isolation and durability [ACID] properties
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen
• CPC Class Codes: G06F 9/466 Transaction processing

Abstract

A process is disclosed by which data is securely deleted in a transactionally consistent manner. This may be accomplished by committing a preparation transaction for a data object within a system managing the data object in order to return the system to an initial condition if necessary, attempting to commit an execution transaction with the data object only after committing the preparation transaction, and securely deleting any portion of the data object necessary to return the system to the initial condition if committing the execution transaction fails and to change the system to a completed condition only if committing the execution transaction succeeds. In a delete or move transaction an existing backup object may be assigned a new logically deleted state such that if the delete or move transaction fails, the data will be made accessible again.

Claims

1. A computer program embodied on a computer readable medium, comprising:

program instructions for committing a preparation transaction for a data object within a system managing the data object in order to return the system to an initial condition if necessary;

program instructions for committing an execution transaction with the data object only after committing the preparation transaction; and

program instructions for securely deleting any portion of the data object necessary to return the system to the initial condition if committing the execution transaction fails and to change the system to a completed condition only if committing the execution transaction succeeds.

2. The computer program of claim 1, wherein no portion of the data object is written by the preparation transaction.

3. The computer program of claim 1, wherein the system is managed with the preparation transaction and the execution transaction committed to a database comprising one or more records associated with the data object including one or more storage locations for the data object.

4. The computer program of claim 3, wherein the one or more records associated with the data object include a state for the data object.

5. The computer program of claim 1, wherein the preparation transaction comprises allocating a storage location for the data object and the execution transaction comprises writing the data object into the storage location to insert the data object into the system;

and

wherein returning the system to the initial condition comprises securely deleting any portion of the data object written to the storage location and changing the system to a completed condition comprises successfully writing the data object to the storage location.

6. The computer program of claim 1, wherein the preparation transaction comprises assigning a logically deleted state to the data object existing at a storage location in the system and the execution transaction comprises deleting the data object in the system;

and

wherein returning the system to the initial condition comprises removing the logically deleted state from the data object at the storage location to make the data object accessible and changing the system to the completed condition comprises successfully securely deleting the data object at the storage location.

7. The computer program of claim 1, wherein the preparation transaction comprises assigning a logically deleted state to the data object existing at a first storage location in the system and allocating a second storage location in the system for the data object and the execution transaction comprises deleting the data object at the first storage location in the system and writing the data object to the second storage location in the system;

and

wherein returning the system to the initial condition comprises removing the logically deleted state from the data object at the first storage location to make the data object accessible and securely deleting any portion of the data object written to the second storage location and changing the system to the completed condition comprises successfully securely deleting the data object at the first storage location and successfully writing the data object to the second storage location.

8. A method, comprising the steps of:

committing a preparation transaction for a data object within a system managing the data object in order to return the system to an initial condition if necessary;

attempting to commit an execution transaction with the data object only after committing the preparation transaction; and

securely deleting any portion of the data object necessary to return the system to the initial condition if committing the execution transaction fails and to change the system to a completed condition only if committing the execution transaction succeeds.

9. The method of claim 8, wherein no portion of the data object is written by the preparation transaction.

10. The method of claim 8, wherein the system condition is managed with the preparation transaction and the execution transaction committed to a database comprising one or more records associated with the data object including one or more storage locations for the data object.

11. The method of claim 10, wherein the one or more records associated with the data object include a state for the data object.

12. The method of claim 8, wherein the preparation transaction comprises allocating a storage location for the data object and the execution transaction comprises writing the data object into the storage location to insert the data object into the system;

and

wherein returning the system to the initial condition comprises securely deleting any portion of the data object written to the storage location and changing the system to a completed condition comprises successfully writing the data object to the storage location.

13. The method of claim 8, wherein the preparation transaction comprises assigning a logically deleted state to the data object existing at a storage location in the system and the execution transaction comprises deleting the data object in the system;

and

wherein returning the system to the initial condition comprises removing the logically deleted state from the data object at the storage location to make the data object accessible and changing the system to the completed condition comprises successfully securely deleting the data object at the storage location.

14. The method of claim 8, wherein the preparation transaction comprises assigning a logically deleted state to the data object existing at a first storage location in the system and allocating a second storage location in the system for the data object and the execution transaction comprises deleting the data object at the first storage location in the system and writing the data object to the second storage location in the system;

and

wherein returning the system to the initial condition comprises removing the logically deleted state from the data object at the first storage location to make the data object accessible and securely deleting any portion of the data object written to the second storage location and changing the system to the completed condition comprises successfully securely deleting the data object at the first storage location and successfully writing the data object to the second storage location.

15. A system, comprising:

a data storage for storing a data object from a client;

a system manager managing storage of the data object from the client by committing a preparation transaction for the data object in order to return the system to an initial condition if necessary, attempting to commit an execution transaction with the data object only after committing the preparation transaction, and securely deleting any portion of the data object necessary to return the system to the initial condition if committing the execution transaction fails and to change the system to a completed condition only if committing the execution transaction succeeds.

16. The system of claim 15, wherein the system comprises a data backup system, the data object comprises a backup object stored, and the data storage comprises a backup repository.

17. The system of claim 15, wherein the system operates over distributed computer system of networked devices.

18. The system of claim 15, wherein the system comprises a distributed data backup system operating over a distributed computer system of networked devices, the data object comprises a backup object, and the data storage comprises a backup repository of the distributed data backup system.

19. The system of claim 15, wherein no portion of the data object is written by the preparation transaction.

20. The system of claim 15, wherein the system condition is managed with the preparation transaction and the execution transaction committed to a database comprising one or more records associated with the data object including one or more storage locations for the data object.