JP5692577B2 - Magnetic disk apparatus and self-diagnosis method - Google Patents

Description

  The present invention relates to a magnetic disk device and a self-diagnosis method.

  In general, a magnetic layer film is formed on a surface of a medium (hereinafter referred to as a disk) built in a magnetic disk device, and a magnetic head has a magnetization pattern (arrangement of N pole and S pole) corresponding to data on this layer. Record. On the other hand, in order to read the recorded data, the magnetic field is detected from the magnetization pattern recorded on the magnetic layer film by the magnetic head, and the data is reproduced.

  The magnetic disk device having such a structure is required to have a large capacity as the amount of information increases. In recent years, the distance between the magnetic head and the disk (the flying height of the magnetic head) is made as close as possible (for example, several The capacity (high recording density) is increased by finely recording N-pole and S-pole magnetic signals on the disk. With such an increase in capacity (high recording density), if a disk or magnetic head is out of order, it is required to detect it early.

  In order to solve such problems, recent magnetic disk devices measure and record characteristic data such as the read error rate, the number of power on / off times, and the temperature of the magnetic disk device during operation after shipment. A smart (Self-Monitoring Analysis and Reporting Technology System = SMART) function that monitors the disk device status, predicts a failure, and generates an alert is installed in advance.

  For example, in Patent Document 1, as an example of the smart function, a storage device in which an inspection area is provided on a disk is disclosed in order to perform a self-test of residual magnetization of a magnetic head that causes a malfunction during writing.

JP 2007-012149 A

  The smart function as described above measures and records characteristic data of the magnetic head used for accessing the disk. Therefore, when a magnetic disk device equipped with a smart function has a plurality of magnetic heads, a magnetic head that is not accessing the disk cannot be monitored, and the failure cannot be predicted or detected.

  Therefore, the present invention intends to propose a magnetic disk device and a self-diagnosis method capable of accurately predicting and detecting failures of all magnetic heads even when a plurality of magnetic heads are provided.

  In order to solve this problem, a magnetic disk device of the present invention includes a magnetic head, a disk having a magnetic head inspection area, and magnetic head inspection means, and the magnetic head inspection area is used for inspecting a magnetic head. A read or write area for reading or writing a pattern, a storage area for storing the characteristic value of the magnetic head measured at the time of shipment, and an inspection at the time of normal use when the inspection result at the time of normal use is different from the inspection result at the time of shipment The magnetic head inspection means performs a read or write operation on the read or write area, and stores the characteristic value of the magnetic head obtained as a result of the execution and the storage area. The characteristic value of the magnetic head at the time of shipment is compared, and when the two are different, the obtained characteristic value of the magnetic head is recorded in the recording area.

  The present invention is also a self-diagnosis method of a magnetic disk device comprising a magnetic head, a disk having a magnetic head inspection area, and a magnetic head inspection means, wherein the magnetic head inspection area is a magnetic head inspection area. Read or write area for reading or writing a pattern, a storage area for storing the characteristic value of the magnetic head measured at the time of shipment, and the normal use when the inspection result at the time of normal use is different from the inspection result at the time of shipment. The magnetic head inspection means includes a step of executing a read or write operation on the read or write area, a characteristic value of the magnetic head obtained as a result of the execution, and a storage area. The step of comparing the characteristic value of the magnetic head stored at the time of shipment and the characteristic value of the magnetic head obtained when both are different, It executes a step of recording the recording area.

  According to the present invention, even when a plurality of magnetic heads are provided, failure of all the magnetic heads can be predicted and detected with high accuracy.

1 is a block diagram showing a configuration of a magnetic disk device 1 according to the present embodiment. It is the schematic which showed the structure of the disk 2 by this Embodiment. 4 is a block diagram showing a configuration of an inspection area 5. FIG. 3 is a flowchart for inspecting a failure of a magnetic head 3 by a magnetic head inspection unit. 6 is an explanatory diagram showing an example of a configuration of data recorded in a result recording area 55. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the following embodiments are exemplifications for explaining the present invention, and are not intended to limit the present invention only to the embodiments. Furthermore, the present invention can be variously modified without departing from the gist thereof.

(1) Configuration of Magnetic Disk Device FIG. 1 is a block diagram showing the configuration of the magnetic disk device 1. The magnetic disk device 1 includes a controller 10 having a CPU (not shown) and a memory (not shown) connected to a bus, a disk 2, a plurality of magnetic heads 3, and each magnetic head 3 being moved on the disk 2. The configuration includes hardware such as an actuator (not shown), a plurality of arms 6 to which the magnetic heads 3 are respectively attached, and a motor 7 that rotates the disk 2.

  Further, the magnetic disk device 1 includes, as general functions, a data write instruction or data read instruction means 11, a recording management means 12 for recording and managing the state of the magnetic disk apparatus 1 in smart information, and the like. In addition, the magnetic head inspection means 13 that inspects the state of the magnetic head 3 using the magnetic head inspection areas 51 to 55 of the disk 2 and reflects the characteristic value of the magnetic head 3 in the smart information, and the magnetic head Alert means 14 for setting an alert based on the smart information reflecting the characteristic value 3. These functions can be realized mainly by the CPU executing a program stored in the memory and controlling each hardware. Some functions may be implemented as a dedicated LSI or the like.

  Smart information for managing the state of the magnetic disk device 1 is recorded in a specific area on the memory or the disk 2. Here, the smart information is various information collected, managed, and monitored by the magnetic disk device 1 itself regarding the state of the magnetic disk device 1, for example, the voltage value of the read signal output from the magnetic head 3 and the occurrence of a read error. Rate (error rate), data verification result, total energization time of the magnetic disk device 1, time required for the disk 2 to reach a specified rotational speed, seek error rate, number of power on / off times, temperature of the magnetic disk device 1, In addition, the latest values, threshold values, and worst values such as the number of abnormal sectors and the number of sectors subjected to substitution processing are recorded.

  FIG. 2 is a schematic diagram showing the configuration of the disk 2. On the recording surface of the disk 2, a data area 4 for recording data and an inspection area 5 for inspecting a failure of the magnetic head 3 are allocated.

(2) Configuration of Inspection Area The inspection area 5 is provided in units of tracks formed concentrically on the disk 2. FIG. 3 is a block diagram showing a configuration of the inspection area 5 when the inspection area 5 is formed for one track. The inspection area 5 is an area for reading or writing an inspection pattern of the magnetic head 3 (read area 51, error detection pattern area 52, and write area 53), and a shipment for storing inspection results at the time of shipment. The time storage area 54 and a result recording area 55 for recording a normal use test result (operation test result) when the normal use test result is different from the shipping test result.

  The read area 51 is an area where a single pattern is recorded in order to measure the voltage value of the read signal output from the magnetic head 3.

  The error detection pattern area 52 is an area where an error detection pattern is recorded in order to measure the read error occurrence rate of the magnetic head 3.

  The write area 53 is an area for verifying normal operation of the write function by recording data output from the magnetic head 3 and reading the recorded data.

  The shipping storage area 54 is an area for recording an inspection result of the magnetic head 3 inspected at the time of shipment (hereinafter referred to as a shipping inspection result). Specifically, the read signal voltage of the magnetic head 3 inspected at the time of shipment. This is an area for recording a value, a read error occurrence rate inspected at the time of shipment, and a verification result of normal operation of the write function inspected at the time of shipment.

  In the result recording area 55, when the inspection result of the magnetic head 3 to be inspected this time does not coincide with the inspection result at the time of shipment, the voltage value of the read signal output from the magnetic head 3, which is the inspection result of the magnetic head 3, is generated. This is an area for recording the rate, the verification result of the normal operation of the write function, and the total energization time of the magnetic disk device 1.

(3) Diagnosis Processing Diagnostic processing in which the magnetic disk device 1 diagnoses a failure of the magnetic head 3 using the inspection area 5 configured as described above will be described with reference to the flowchart shown in FIG. This diagnosis process is sequentially executed for a plurality of magnetic heads 3. Further, the magnetic head inspection unit 13 of the magnetic disk device 1 executes a diagnostic process at any timing when the magnetic disk device 1 is started, when smart information is updated, or when a diagnostic command is issued.

  First, the magnetic head inspection means 13 executes steps S1 to S3 in order to inspect the state in which the magnetic head 3 reads and writes. That is, when the magnetic head inspection means 13 moves the magnetic head 3 to the single pattern area of the inspection area 5, it detects the position of the single pattern recorded in this area, reads the single pattern, and The voltage value of the read signal output from the head 3 is measured (S1).

  Next, when the magnetic head inspection unit 13 moves the magnetic head 3 to the error detection pattern area 52, the magnetic head inspection means 13 detects the position of the error detection pattern recorded in the error detection pattern area 52, and the error detection pattern. The read error rate is measured based on the number of bits that the magnetic head 3 has failed to read (S2).

  Thereafter, when the magnetic head inspection means 13 moves the magnetic head 3 to the write area 53, the magnetic head inspection means 13 detects the position of the write area 3, records the data output from the magnetic head 3 in the write area 53, and records it. Data is read to verify whether the data is written without error (S3). For example, a value that is different from the written value and the read value can be used as the verification result.

  When the magnetic head inspection means 13 detects each inspection result of steps S1 to S3 as an inspection result during normal use (operational inspection result), the magnetic head 3 is moved to the shipping storage area 54 to detect the position. To do. The magnetic head inspecting means 13 includes each inspection result (characteristic value of the magnetic head at the time of shipment) recorded in advance from the storage area 54 at the time of shipment, that is, the read signal voltage value of the magnetic head 3 inspected at the time of shipment, Read the read error occurrence rate checked at the time of shipment and the verification result of the normal operation of the write function checked at the time of shipment. Thereafter, the magnetic head inspecting means 13 carries out the inspection results at the time of shipment recorded in the storage area 54 at the time of shipment in advance and the inspection results at the time of operation of the magnetic head 3 (characteristic values of the magnetic head obtained at this time). Are compared (S4). Specifically, the magnetic head inspection means 13 verifies the voltage value and initial value of the read signal measured this time, the read error occurrence rate and initial value measured this time, and the normal operation of the write function examined this time. The result and the verification result of the normal operation of the light function inspected at the time of shipment are compared.

  When the magnetic head inspection unit 13 determines that the current operation inspection result does not coincide with each shipping inspection result (S4: NO), the magnetic head inspection unit 13 moves the magnetic head 3 to the result recording area 55 and detects the position. The inconsistent operation inspection result and the total energization time of the magnetic disk device 1 are recorded in the result recording area 55 (S5).

  When the magnetic head inspection unit 13 reflects the inconsistent operation inspection result as the latest value in the smart information (S6), the diagnostic processing is terminated.

  On the other hand, when the magnetic head inspection unit 13 determines that the current operation inspection result matches each inspection inspection result (S4: YES), the magnetic head inspection means 13 records the current operation inspection result in the result recording area 55. And the diagnosis process is terminated without being reflected in the smart information.

  When the magnetic head inspection unit 13 finishes the diagnosis process, the alert unit 14 compares the current operation inspection result with the threshold value registered in the smart information, and if the current operation inspection result exceeds the threshold value. Determines that there is a failure or a sign of failure in the magnetic disk device 1 and sets an alert.

  As described above, the magnetic head inspection unit 13 executes the diagnostic process for each magnetic head 3 at any timing of when the magnetic disk device 1 is started, when smart information is updated, and when a diagnostic command is issued. When the characteristic value of the magnetic head 3 obtained this time and the characteristic value of the magnetic head 3 at the time of shipment do not match, the characteristic value of the magnetic head 3 obtained this time is reflected in the smart information. The failure can be predicted based on the smart information of the magnetic head 3 regardless of whether the magnetic head 3 is used. If the magnetic head 3 that is not used for access has already failed, the failure can be detected in a timely manner.

(4) Recording Method in Result Recording Area Next, as described above, a method for recording the operation inspection result that the magnetic disk device 1 has determined to be inconsistent with each shipping inspection result as data in the result recording area 55 is as follows. This will be described with reference to FIG.

  In the result recording area 55 in the present embodiment, areas 551 to 55n in which N pieces of data D1 to Dn can be recorded are secured. Of the areas 551 to 55n that record N pieces of data D1 to Dn, the areas 551 to 55m that record M pieces of data D1 to Dm include the inspection results at the time of operation determined to be inconsistent with the inspection results at the time of shipment. In the areas 55m + 1 to 55n in which M + 1 to N pieces of data Dm + 1 to Dn are recorded, the latest data of the operation inspection result is recorded. Since the magnetic head 3 is set so as to move in a ring shape on each of the areas 55m + 1 to 55n in which the data Dm + 1 to Dn are recorded, the N + 1 and subsequent operation inspection results record the data Dm + 1. It is overwritten in order from the area 55m + 1. By recording in this way, it is possible to always keep the latest operation inspection result while keeping the initial data of the operation inspection result determined to be inconsistent with each shipping inspection result.

  As described above, for convenience of explanation in the present embodiment, one disk 2 is shown in FIG. 2, but the magnetic disk device 1 may include a plurality of disks 2. Further, both surfaces of one disk 2 may be recording surfaces. In this case, the magnetic head 3 is provided for each recording surface of the disk 2.

  In the present embodiment, the case where the inspection area 5 is arranged on any one track has been described. However, the inspection area 5 may be arranged on a total of two tracks, for example, the inner circumference and the outer circumference of the disk 2. As the number of areas 5 is increased, the accuracy of predicting a failure of the magnetic head 3 is improved. Further, the inspection area 5 may be continuously arranged in two or three continuous tracks, and one of these tracks may be used as the inspection area 5 and another track may be used as a spare area. By arranging the spare area in this way, it is possible to avoid the influence of the scratches on the disk 2.

  As described above, in this embodiment, it is possible to predict and detect a failure with high accuracy even when a plurality of magnetic heads are provided.

  The present invention can be widely applied to magnetic disk devices having one or more disks.

  DESCRIPTION OF SYMBOLS 1 ... Magnetic disk apparatus, 2 ... Magnetic medium (disk), 3 ... Magnetic head, 4 ... Data area, 5 ... Inspection area, 51 ... Read area, 52 ... Error detection pattern area, 53 ... Write area, 54 ... recording area at shipping, 55 ... result recording area, 551 to 55n ... each area in the result recording area, D1 to Dn ... data, 6 ... arm, 7 ... motor, 10 ... controller, 11 ... write read instruction means, 12 ... Recording management means, 13 ... Magnetic head inspection means, 14 ... Alert means.

Claims (6)

A magnetic head;
A disk having a magnetic head inspection area;
Magnetic head inspection means,
The magnetic head inspection area includes a read or write area for reading or writing an inspection pattern of the magnetic head, a storage area for storing characteristic values of the magnetic head measured at the time of shipment, and an inspection during normal use A recording area having a first area and a second area for recording the inspection result at the time of normal use when the result is different from the inspection result at the time of shipping; and
The magnetic head inspection means executes a read or write operation on the read or write area, and the magnetic head characteristic value obtained as a result of the execution and the magnetic head at the time of shipment stored in the storage area And when the two are different, the characteristic value of the obtained magnetic head is recorded in the recording area ,
Recording the obtained characteristic value of the magnetic head in the recording area records initial data of the characteristic value of the magnetic head when the two are different in the first area, and records both in the second area. Recording the latest data of the characteristic values of the magnetic head when
Magnetic disk unit.   The magnetic head inspection means performs a read or write operation on the read or write area at any one of the timing of starting the magnetic disk device, updating smart information, and issuing an inspection command to the magnetic head. The magnetic disk device according to claim 1, wherein the characteristic value of the obtained magnetic head is recorded in the recording area when both are different from each other. Furthermore, an alert means based on smart information is provided,
The magnetic head inspecting means reflects the obtained magnetic head characteristic value information in the smart information used by the alert means when recording the obtained magnetic head characteristic value in the recording area. The magnetic disk device according to claim 1 or 2. A magnetic head;
A disk having a magnetic head inspection area;
A self-diagnosis method of a magnetic disk device comprising a magnetic head inspection means,
The magnetic head inspection area includes a read or write area for reading or writing an inspection pattern of the magnetic head, a storage area for storing characteristic values of the magnetic head measured at the time of shipment, and an inspection during normal use A recording area having a first area and a second area for recording the inspection result at the time of normal use when the result is different from the inspection result at the time of shipping; and
The magnetic head inspecting means executes a read or write operation on the read or write area, a characteristic value of the magnetic head obtained as a result of the execution, and the shipping time stored in the storage area A step of comparing the characteristic value of the magnetic head, and a step of recording the characteristic value of the obtained magnetic head in the recording area when both are different , and
The step of recording the characteristic value of the obtained magnetic head in the recording area records initial data of the characteristic value of the magnetic head when the two are different from each other in the first area, and records the both in the second area. A self-diagnosis method including recording the latest data of the characteristic values of the magnetic head when the values of the magnetic heads are different .   The magnetic head inspection means performs a read or write operation on the read or write area at any one of the timing of starting the magnetic disk device, updating smart information, and issuing an inspection command to the magnetic head. 5. The self-diagnosis method according to claim 4, wherein the characteristic value of the obtained magnetic head is recorded in the recording area when the two are different from each other. Furthermore, an alert means based on smart information is provided,
The magnetic head inspecting means reflects the obtained magnetic head characteristic value information in the smart information used by the alert means when recording the obtained magnetic head characteristic value in the recording area. The self-diagnosis method according to claim 4 or 5.

Images