Monitoring of residual encrypted data to improve erase performance on a magnetic medium

Patent metadata

Field	Value
Publication number	US-9904488-B2
Application number	US-201615213198-A
Country	US
Kind code	B2
Filing date	Jul 18, 2016
Priority date	Jul 17, 2012
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

In one embodiment, a product includes a magnetic medium having written thereon data in a data track. The data includes encrypted data written over unencrypted data. An indicator of a physical position on the magnetic medium that corresponds to an end of the encrypted data is stored on the product. A product according to another embodiment includes a magnetic medium having written thereon data in a data track. The data includes encrypted data written over unencrypted data. A portion of the unencrypted data is located before the encrypted data on the medium. An indicator of a physical position on the magnetic medium that corresponds to a beginning of the encrypted data is stored on the product.

First claim

What is claimed is:

1. A product, comprising:
a magnetic medium having written thereon data in a data track,
wherein the data includes encrypted data written over unencrypted data,
wherein an indicator of a physical position on the magnetic medium that corresponds to an end of the encrypted data is stored on the product,
wherein the unencrypted data is obscured after the physical position,
wherein the obscured unencrypted data is followed by unobscured unencrypted data on the magnetic medium, wherein the obscured unencrypted data is characterized by being overwritten, wherein a second indicator of a physical position on the magnetic medium that corresponds to an end of the obscured unencrypted data is stored on the product.

2. The product as recited in claim 1 , wherein the indicator is stored on the magnetic medium.

3. The product as recited in claim 1 , wherein the indicator is stored in a nonvolatile memory coupled to the magnetic medium.

4. The product as recited in claim 1 , wherein the encrypted data is not obscured.

5. The product as recited in claim 1 , wherein the magnetic medium is a magnetic recording tape.

6. The product as recited in claim 1 , wherein the unencrypted data, located after the physical position on the magnetic medium that corresponds to the end of the encrypted data, is obscured.

7. The product as recited in claim 6 , wherein the unencrypted data located after the physical position is obscured.

8. The product as recited in claim 6 , wherein a portion of the unencrypted data is located before the encrypted data on the magnetic medium, wherein a second indicator of a physical position on the magnetic medium that corresponds to a beginning of the encrypted data is stored on the product.

9. The product as recited in claim 8 , wherein the unencrypted data, located before the physical position on the magnetic medium that corresponds to the beginning of the encrypted data, is obscured.

10. The product as recited in claim 9 , wherein the encrypted data is not obscured.

11. The product as recited in claim 10 , wherein the unencrypted data, located after the physical position on the magnetic medium that corresponds to the end of the encrypted data is stored on the product, is obscured.

12. The product as recited in claim 6 , wherein the obscured unencrypted data is followed by unobscured unencrypted data on the magnetic medium, wherein a second indicator of a physical position on the magnetic medium that corresponds to an end of the obscured unencrypted data is stored on the product.

13. A product, comprising:
a magnetic medium having written thereon data in a data track,
wherein the data includes encrypted data written over unencrypted data,
wherein an indicator of a physical position on the magnetic medium that corresponds to an end of the encrypted data is stored on the product,
wherein the unencrypted data is obscured after the physical position,
wherein the obscured unencrypted data is followed by unobscured unencrypted data on the magnetic medium, wherein a second indicator of a physical position on the magnetic medium that corresponds to an end of the obscured unencrypted data is stored on the product,
wherein the encrypted data is residual encrypted data, wherein new encrypted data is written over a portion of the residual encrypted data.

14. The product as recited in claim 13 , wherein the residual encrypted data is not obscured.

15. A product, comprising:
a magnetic medium having written thereon data in a data track,
wherein the data includes encrypted data written over unencrypted data,
wherein a portion of the unencrypted data is located before the encrypted data on the magnetic medium, wherein an indicator of a physical position on the magnetic medium that corresponds to a beginning of the encrypted data is stored on the product;
the magnetic medium having unencrypted data located after a physical position on the magnetic medium that corresponds to an end of the encrypted data, wherein the unencrypted data located after the physical position on the magnetic medium that corresponds to the end of the encrypted data is obscured, wherein the obscured unencrypted data is followed by unobscured unencrypted data on the magnetic medium, wherein a second indicator of a physical position on the magnetic medium that corresponds to an end of the obscured unencrypted data is stored on the product.

16. The product as recited in claim 15 , wherein the indicators are stored on the magnetic medium.

17. The product as recited in claim 15 , wherein the indicators are stored in a nonvolatile memory coupled to the magnetic medium.

18. The product as recited in claim 15 , wherein the unencrypted data, located before the physical position on the magnetic medium that corresponds to the beginning of the encrypted data, is obscured.

19. The product as recited in claim 18 , wherein the encrypted data is not obscured.

Assignees

• IBM

Inventors

• Dawson Erika M
• Fry Scott M
• Greco Paul M
• Johnson Gavin S
• Lyman Joel K
• Lynds Jon A
• Smith Cory G

Classifications

• G11B20/10

  Digital recording or reproducing · CPC title

• G06F3/0604

  Improving or facilitating administration, e.g. storage management · CPC title

• G11B27/322

  used signal is digitally coded · CPC title

• G11B5/09

  Digital recording · CPC title

• G11B5/00821

  using stationary heads · CPC title