Magnectic disk protection mechanism, computer system comprising protection mechanism, protection method for magnetic disk, and program for protection method

• US 20040125493A1
• Filed: 10/01/2003
• Published: 07/01/2004
• Est. Priority Date: 10/03/2002
• Status: Active Grant

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Ogawa, Mitsuru, Shimotono, Susumu, Tanaka, Akiyoshi, Noguchi, Tetsuya
• Granted Patent: US 7,042,663 B2
• Time in Patent Office: Days
• US Class Current: 360/75
• CPC Class Codes: G11B 19/04 Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
• CPC Class Codes: G11B 21/12 Raising and lowering; Back-spacing or forward-spacing along track; Returning to starting position otherwise than during transducing operation
• CPC Class Codes: G11B 5/5582 system adaptation for working during or after external perturbation, e.g. in the presence of a mechanical oscillation caused by a shock

Abstract

A magnetic disk device protection mechanism comprises a sensor that acquires information on changes in the environment of a magnetic disk device, a sensor driver, a shock manager that analyzes the information acquired by the sensor driver together with a history of the information to determine the status where the magnetic disk device is used to predict a shock, and an HDD filter driver that controls operations of the magnetic disk device including the escape of a magnetic head. The magnetic disk device can also comprise a diagnosis processing section that operates if a shock has occurred actually, to check whether or not the magnetic head could have completely escaped before the occurrence of this shock to carry out diagnosis as to whether or not a fault is occurring in the magnetic disk.

Claims

1. A magnetic disk protection mechanism, comprising:

an information acquisition mechanism for acquiring information about an environmental change of a magnetic disk device;

a shock prediction mechanism for analyzing the information acquired by said information acquisition mechanism together with a history thereof, and for determining a status of where said magnetic disk device is used, so as to perform a shock prediction; and

a control mechanism for controlling operations of said magnetic disk device including a magnetic head escape operation based on a prediction result by said shock prediction mechanism.

2. The magnetic disk protection mechanism according to claim 1, wherein if a variation in the status where said magnetic disk device is used falls within a specified range for a specified period, said shock prediction mechanism does not predict that a shock will be caused by the variation in the status.

3. The magnetic disk protection mechanism according to claim 1, wherein if the status of where said magnetic disk device is used varies in a predetermined pattern, said shock prediction mechanism predicts that a shock will be caused by the variation in the status.

4. The magnetic disk protection mechanism according to claim 1, wherein said shock prediction mechanism predicts a shock with reference to a history of input operations provided by a predetermined input device.

5. The magnetic disk protection mechanism according to claim 1, wherein said information acquiring mechanism acquires information on acceleration of said magnetic disk device, and said shock prediction mechanism recognizes the status where the magnetic disk device is used based on the acceleration information acquired by said information acquiring mechanism.

6. The magnetic disk protection mechanism according to claim 1, wherein if said shock prediction mechanism determines that said magnetic disk device is stable, the shock prediction mechanism notifies said control mechanism that said magnetic disk device is stable, and said control mechanism returns said escaping magnetic head in response to said notification.

7. The magnetic disk protection mechanism according to claim 6, wherein said shock prediction mechanism adaptively determines whether or not said magnetic disk device is stable, based on a history of the information acquired by said information acquiring mechanism before a shock is predicted to occur.

8. The magnetic disk protection mechanism according to claim 1, wherein if said magnetic head has escaped, said control mechanism holds a new access request to the magnetic disk device in an internal queue instead of realizing the access request until said shock prediction mechanism determines that said magnetic disk device is stable.

9. A magnetic disk protection mechanism, comprising:

a status determination mechanism for determining a status of where said magnetic disk device is used; and

a control mechanism for controlling operations of said magnetic disk device including a magnetic head escape operation based on a determination result by said status determination mechanism,

wherein, when said status determination mechanism determines that there is a high probability of excessive shock to said magnetic disk device, said control mechanism divides an access request to said magnetic disk device into access requests with a small data size per access and transmits the access request to said magnetic disk device.

10. The magnetic disk protection mechanism according to claim 9, wherein if said magnetic head escapes before at least some of said access requests obtained by the division are realized, said control mechanism saves the access requests that have not been realized yet and realizes these requests after returning said magnetic head.

11. The magnetic disk protection mechanism according to claim 9, wherein, instead of said control mechanism dividing an access request to said magnetic disk device into access requests with a small data size per access and transmitting the access request to said magnetic disk device, said control mechanism invalidates a write cache function that performs an access to a magnetic disk in said magnetic disk device when said status determination mechanism determines that there is a high probability of excessive shock to said magnetic disk device.

12. The magnetic disk protection mechanism according to claim 11, wherein, instead of said control mechanism invalidating a write cache function that performs an access to a magnetic disk in said magnetic disk device, for each data writing in a cache memory, said control mechanism writes said data to a magnetic disk so as to empty said cache memory.

13. A magnetic disk protection mechanism, comprising:

a shock prediction mechanism for predicting a possible shock to a magnetic disk device, based on a variation in at least one physical parameter of an environment of the magnetic disk device;

a control mechanism for controlling operations of said magnetic disk device including a magnetic head escape operation based on a prediction result by said shock prediction mechanism; and

a diagnosis mechanism for operating if a shock actually occurs after said control mechanism has started causing a magnetic head to escape, to determine whether or not the magnetic head has escaped before the occurrence of the shock.

14. The magnetic disk protection mechanism according to claim 13, wherein said diagnosis mechanism makes said determination by comparing a pre-shock period, that is a time from a start of an escape operation of the magnetic head until the occurrence of a shock, with an already measured and restored escape time required for the escape operation of the magnetic head.

15. The magnetic disk protection mechanism according to claim 14, wherein if the magnetic head has already escaped before the magnetic head starts an escape operation under the control of said control mechanism, said diagnosis mechanism does not compare said pre-shock period with said escape time but determines that the magnetic head has completely escaped before the occurrence of said shock.

16. The magnetic disk protection mechanism according to claim 15, wherein if said control mechanism issues a request command requesting performance of an escape operation under the control of said control mechanism and then within a specified time, acquires a notification indicating that the command has been completed, then said diagnosis mechanism determines that the magnetic head had already escaped when the magnetic head started an escape operation.

17. A computer system comprising a magnetic disk device, said computer system further comprising:

an acceleration sensor for detecting an acceleration of a housing coupled to said magnetic disk device;

a shock manager for analyzing acceleration information acquired by said acceleration sensor and a history thereof, to predict a probability of shock to said magnetic disk device; and

a driver for controlling said magnetic disk device operation including a disk head escape operation based on a prediction result by said shock manager.

18. The computer system according to claim 17, further comprising a diagnosis processing section for operating if a shock actually occurs after said driver has started causing a magnetic head to escape, to determine whether or not the the magnetic head has escaped before the occurrence of the shock.

19. The computer system according to claim 18, wherein if said diagnosis processing section determines that a shock occurred before the magnetic head escape was completed, said diagnosis processing section provides a user notification warning a user that a fault may have occurred in the magnetic disk device.

20. A computer system comprising a magnetic disk device, said computer system further comprising:

a shock manager for determining a status where a housing of said shock manager is used to predict a shock to said magnetic disk device; and

a driver for dividing an access request to said magnetic disk device into access requests with a small data size per access and for transmitting to said magnetic disk device when said shock manager finds a high possibility of excessive shock to said magnetic disk device.

21. The computer system according to claim 20, wherein the driver, instead of dividing an access request to said magnetic disk device into access requests with a small data size per access and for transmitting to said magnetic disk device, invalidates a write cache function that performs an access to a magnetic disk of said magnetic disk device when said shock manager finds a high possibility of excessive shock to said magnetic disk device.

22. A magnetic disk protection method of protecting a magnetic disk by using a sensor to determine a status where a magnetic disk device is used and by having a magnetic head escape depending on a determination result, said magnetic disk protection method comprising:

accumulating information histories acquired by said sensor,

analyzing the accumulated histories and the latest said information to recognize a change pattern of said magnetic disk device status, and

based on a content of said change of said magnetic disk device status, executing a magnetic head escape operation when a shock to said magnetic disk device is predicted.

23. A magnetic disk protection method of protecting a magnetic disk by using a sensor to determine a status where a magnetic disk device is used and by having a magnetic head escape depending on a determination result, said magnetic disk protection method comprising:

based on an output by said sensor, determining a status of where said magnetic disk device is used;

controlling operations of division of an access request to said magnetic disk device into access requests with a small data size per access and of transmission to said magnetic disk device when a high possibility of excessive shock to said magnetic disk device is predicted; and

executing a magnetic head escape operation when a shock to said magnetic disk device is found.

24. The method according to claim 23, wherein instead of controlling operations of division of an access request to said magnetic disk device into access requests with a small data size per access and of transmission to said magnetic disk device, operations to invalidate a write cache function that performs an access to a magnetic disk in said magnetic disk device are controlled when a high possibility of excessive shock to said magnetic disk device is found.

25. The method according to claim 23, wherein instead of controlling operations of division of an access request to said magnetic disk device into access requests with a small data size per access and of transmission to said magnetic disk device, for each data writing in a cache memory, controlling an operation of writing of data to a magnetic disk so as to empty said cache memory when a high possibility of excessive shock to said magnetic disk device is found.

26. A magnetic disk prediction method of protecting a magnetic disk by using a sensor to determine a status of where said magnetic disk device is used and by having a magnetic head escape depending on a determination result, said magnetic disk prediction method comprising:

based on a variation in an environment of the magnetic disk device, predicting a possible shock to the magnetic disk device;

based on a result of said prediction, controlling operations of said magnetic disk device including a magnetic head escape operation; and

if a shock actually occurs after a magnetic head has started escaping, determining whether or not the magnetic head escape has been completed before the occurrence of the shock, by comparing a pre-shock period, that is a time from a start of an escape operation of the magnetic head until the occurrence of a shock, with an already measured and restored escape time required for the escape operation of the magnetic head.

27. The method according to claim 26, wherein in the step of determining whether or not the magnetic head escape has been completed before the occurrence of said shock, if the magnetic head has already escaped before the magnetic head starts an escape operation, the comparison of said pre-shock period with said escape time is not carried out but it is determined that the magnetic head has completely escaped before the occurrence of said shock.

28. A program for controlling a computer to implement a magnetic disk device protection mechanism, comprising:

code for acquiring information on an environmental change toward a magnetic disk device and storing the information in a predetermined storage mechanism;

code for analyzing said acquired information and a history of the information accumulated in said storage mechanism, and for determining a status of where said magnetic disk device is used, so as to perform a shock prediction; and

code for controlling operations of said magnetic disk device including a magnetic head escape operation based on a result of said shock prediction.