Method and apparatus for erasing data when a problem is identified

• US 6,301,670 B1
• Filed: 10/06/1998
• Issued: 10/09/2001
• Est. Priority Date: 10/06/1998
• Status: Expired due to Term

• Current Assignee: Ricoh Americas Corporation (Ricoh Company Limited)
• Original Assignee: Ricoh Company Limited, Ricoh Corporation (Ricoh Company Limited)
• Inventors: Motoyama, Tetsuro, Yachida, Masuyoshi
• Primary Examiner(s): Wiley, David
• Assistant Examiner(s): JEAN, FRANTZ B
• Application Number:
  US09/167,184
• Time in Patent Office: 1,099 Days
• Field of Search: 707/203, 707/205, 711/162, 713/300, 704/6, 704/7, 704/8
• US Class Current: 713/300
• CPC Class Codes: G06F 21/80 in storage media based on magnetic or optical technology, e.g. disks with sectors preventing unauthorised reproduction or copying of disc-type recordable media G11B20/00
• CPC Class Codes: G11C 29/74 using duplex memories, i.e. using dual copies
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

An approach for storing and maintaining data involves determining whether a first non-volatile storage has failed or otherwise encountered a problem. If so, then the data on the first non-volatile storage is deleted by overwriting the data on the first non-volatile storage with a predetermined value so that the data cannot be recovered. The first non-volatile storage is registered with a registration authority to provide authentication of the data maintained on the first non-volatile storage. A duplicate copy of the data is stored on a second non-volatile storage and if a determination is made that the first non-volatile storage has experienced a problem, then the duplicate copy of the data on the second non-volatile storage becomes active.

Claims

1. A method for storing and maintaining data, the method comprising the steps of:

storing data on a first non-volatile storage device in a manner that allows modification of the set of data only in response to a failure of the first non-volatile storage device;

storing a copy of the data on a second non-volatile storage in a manner that allows modification of the copy of the set of data only in response to a failure of the second non-volatile storage device; and

in response to a failure of the first non-volatile storage device, deleting the data from the first non-volatile storage device by overwriting the data on the first non-volatile storage device with a specified value, and

prohibiting writing any data to or reading any data from the first non-volatile storage device.

2. A method as recited in claim 1, wherein the step of overwriting the data on the first non-volatile storage device with the specified value includes the step of overwriting the data on the first non-volatile storage device with the value 00H.

3. A method as recited in claim 2, further including the step of deleting a file directory entry associated with the data.

4. A method as recited in claim 1, further including the step of in response to a power failure of the first non-volatile storage device, providing power to the first non-volatile storage device from a backup power supply.

5. A method as recited in claim 4, further including the step of after power has been restored to the storage unit, allowing data to be written to and read from the storage unit.

6. A data storage unit for storing and maintaining data, the data storage unit comprising:

a first non-volatile storage device; and

a processing unit communicatively coupled to the first non-volatile storage device, wherein

the processing unit is configured to store data on the first non-volatile storage device,

store a copy of the data on a second non-volatile storage device, and

determine whether a failure of the first non-volatile storage device has occurred and if so, delete the data on the first non-volatile storage device by overwriting the data on the first non-volatile storage device with a predetermined value, and prohibit writing data to or reading data from the first non-volatile storage device.

9. A data storage unit as recited in claim 6, wherein the processing unit is further configured to in response to a power failure of the first non-volatile storage device, provide power to the first non-volatile storage device from a backup power supply.

10. A data storage unit as recited in claim 9, wherein the processing unit is further configured to after power has been restored to the storage unit, allowing data to be written to and read from the storage unit.

7. A data storage unit for storing and maintaining data, the data storage unit comprising:

a first non-volatile storage device; and

a processing unit communicatively coupled to the first non-volatile storage device, wherein

the processing unit is configured to store data on the first non-volatile storage device in a manner that allows modification of the data only in response to a failure of the first non-volatile storage device,

store a copy of the data on a second non-volatile storage device in a manner that allows modification of the copy of the data only in response to a failure of the second non-volatile storage device, and

determine whether a failure of the first non-volatile storage device has occurred and if so, delete the data on the first non-volatile storage device by overwriting the data on the first non-volatile storage device with a specified value, and prohibit writing any data to or reading any data from the first non-volatile storage device.

8. A data storage unit as recited in claim 7, wherein the processing unit is further configured to delete a file directory entry associated with the data.

11. A computer-readable medium carrying one or more sequences of one or more instructions for storing and maintaining data, the one or more sequences of one or more instructions including instructions which, when executed by one or more processors, cause the one or more processors to perfonn the steps of:

storing data on a first non-volatile storage device in a manner that allows modification of the set of data only in response to a failure of the first non-volatile storage device;

storing a copy of the data on a second non-volatile storage in a manner that allows modification of the copy of the set of data only in response to a failure of the second non-volatile storage device; and

in response to a failure of the first non-volatile storage device,

deleting the data from the first non-volatile storage device by overwriting the data on the first non-volatile storage device with a specified value, and

prohibiting writing any data to or reading any data from the first non-volatile storage device.

12. A computer-readable medium as recited in claim 11, wherein the step of overwriting the data on the first non-volatile storage device with the specified value includes the step of overwriting the data on the first non-volatile storage device with the value 00H.

13. A computer-readable medium as recited in claim 12, further including the step of deleting a file directory entry associated with the data.

14. A computer-readable medium as recited in claim 11, further including the step of in response to a power failure of the first non-volatile storage device, performing the steps of providing power to the first non-volatile storage device from a backup power supply.

15. A computer-readable medium as recited in claim 14, further including the step of after power has been restored to the storage unit, allowing data to be written to and read from the storage unit.