JP2000348452A - Disk unit - Google Patents

Abstract

(57) [Problem] To solve the difficulty of simultaneous positioning of all disk surfaces to a desired track due to a reduced track pitch,
In addition, data must be protected from reliability deterioration due to increase in recording density. SOLUTION: This disk device comprises a plurality of disks (301) surfaces for recording or reproducing data, a head 303 provided corresponding to each disk surface, and an actuator for accessing the disk surface with a head. A micro-positioning mechanism 304 for micro-positioning the head for each individual head or for each actuator that operates a plurality of heads collectively. After accessing the heads simultaneously on a plurality of disk surfaces, each head is finely positioned on a desired track. A disk device that positions and records or reproduces data on multiple disk surfaces. Further, based on information relating to the reliability or life of the disk device, the data storage format is changed on the disk surface, and the data is saved or a warning is issued to protect the data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive using a disk-type storage medium such as a magnetic disk or a magneto-optical disk, and simultaneously performing read / write operations on a plurality of disk surfaces using a plurality of heads. It relates to a disk device.

[0002]

2. Description of the Related Art A disk device having a plurality of disk surfaces for recording data and a plurality of heads for accessing the disk surfaces, and simultaneously accessing, recording, and reproducing the plurality of disk surfaces, and the disk device. Japanese Patent Laid-Open Publication No. 06-309113 discloses a disk device in which redundancy data is added to the disk device to improve reliability.

The above publication discloses the basic concept of a disk device for simultaneous access, but discloses a technique for practical simultaneous access to a disk device recorded at a high density at a narrow track pitch. Not.

[0004]

In the prior art,
Based on the servo signal recorded on the disk surface read from the head, its own position is determined, and the plurality of heads mounted on one actuator are positioned by driving the actuator to record / record data. Access the playback position.

[0005] In recent years, in a disk device, the recording density has been remarkably improved, and the interval between data tracks (track pitch) has been narrowed accordingly.

[0006] As a result, even if a plurality of tracks can be accessed at one time in one environment, all necessary tracks can be simultaneously accessed in another environment, that is, by displacement when temperature or humidity changes. Is becoming more difficult.

[0007] Even if the head is simultaneously positioned at, for example, the average position of each track between different disk surfaces, the displacement due to the temperature distribution in the disk device is reduced to 0. Since about 3 μm occurs, the positioning accuracy for each track cannot be maintained, and as a result, a sufficient S / N ratio cannot be maintained.

The deterioration of the S / N ratio becomes remarkable especially when the track pitch is less than 1 μm. That is, it becomes impossible to simultaneously reproduce all the data of the necessary tracks without any trouble.

To improve the recording density, for example, in a magnetic disk drive, an MR head (GMR
In order to increase the sensitivity of the head (including the head, etc.), the current flowing through the MR element has been increased, and the head-disk distance has been reduced. However, these methods shorten the life of the head or reduce the disk of the head. Cause a crash.

When the head life or disk crash occurs, if the recorded data has redundancy corresponding thereto, the data can be recovered, but the abnormal surface cannot be used thereafter. Therefore, it is necessary to define a process when an abnormality relating to the service life or the reliability of the device is predicted or when the abnormality occurs.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a device for positioning each head with respect to a plurality of disk surfaces, and a device for abnormal processing relating to reliability or life of a disk device. That is, it is possible to eliminate the difficulty of simultaneous positioning of all the disk surfaces on desired tracks due to a decrease in track pitch, and to protect data from a decrease in reliability due to an increase in recording density.

[0012]

In order to solve the above problems, the present invention mainly employs the following configuration.

[0013] A disk device comprising: a plurality of disk surfaces for recording or reproducing data; a head provided for each disk surface; and an actuator for accessing the head on the disk surface. A fine positioning mechanism for finely positioning the head for each of the heads or for each actuator that operates a plurality of heads collectively. After the heads are simultaneously accessed on a plurality of disk surfaces by the actuator, each head is controlled by the fine positioning mechanism. A disk device for recording or reproducing data on or from the plurality of disk surfaces by minutely positioning the disk on a desired track.

In the disk device, data is protected by changing the storage format of the data on the disk surface, saving or warning the data, based on information relating to the reliability or life of the disk device. Disk device.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A disk drive according to an embodiment of the present invention will be described below with reference to FIGS. FIG.
FIG. 2 is a flowchart showing a specific example of a read operation of the disk device of the present embodiment, and FIG. 2 is a flowchart showing a specific example of processing contents when an error relating to reliability or life of the disk device of the present embodiment occurs. FIG. 3 is a diagram illustrating a configuration example of the disk device of the present embodiment, and FIG. 4 is a diagram illustrating another configuration example of the disk device of the present embodiment.

Here, 101 to 112 are steps of a flow showing a specific example of a read operation, 201 to 211 are steps of a flow showing a specific example of error processing relating to reliability, and 3
01 is a data recording disk, 302 is a disk drive spindle motor, 303 is a data recording and reproducing head, 303a to 303d are individual data recording and reproducing heads, and 304 is a minute positioning mechanism.

In FIG. 1, when a disk device receives a read command (101), it obtains a physical address of necessary data from its logical address, transfer length and the like (102), moves to a cylinder having the target address, and Almost position to target cylinder (10
3).

For this positioning, for example, an actuator is driven so as to position the head using the center head as a reference head, or the actuator is driven to an average position determined from positioning signals of a plurality of heads. And other means.

Thereafter, the deviation of the individual head from the track position is sensed by reading the servo signal for each individual head, and the individual heads or a specified group of heads are finely adjusted (104). The rotation is waited until a necessary data sector is reached (105), and the contents of a desired sector are read (106).

The read data is discriminated as to whether or not there is a failure (107). If there is a failure, processing for data abnormalities and failures is performed (108, 109, 110), and if there is no failure or the failure can be recovered. If so, the data is transferred to the host computer (111). Further, when reading data continuously, the processing is repeated (112) and the processing is ended.

In this series of flows, the provision of the head position fine adjustment 104 is one of the features of the present invention.
In this case, since a plurality of disk surfaces are simultaneously accessed and reproduced (simultaneous access can be used for recording), deviation from the track position of each head is detected and adjusted. At this time, until the head position fine adjustment (104) is completed for all necessary heads,
It is not necessary to wait for data processing, and data can be read from the head for which positioning has been completed, and data processing can be started.

In this case, even if the processing of the data from one or more recording surfaces is not completed yet, the data processing is terminated when the decoding of the read data is completed, The following processing can be performed.

For example, data is mirrored (RAID
-1), the same data is read from the two disk surfaces, so if there is no obstacle in the data read from the head whose positioning has been completed early, or
If the failure can be recovered, there is no need to wait until the processing for the data from the other head is completed.

Alternatively, when redundancy is provided by using parity data (corresponding to RAID 3 to 5), it is possible to decode data from the last one head before processing. Conversely, for a user who requires a high degree of reliability, the data can be made highly reliable by waiting for the processing until the collation of all data is completed.

FIG. 2 shows an example of processing contents when error information relating to the reliability or life of the disk device occurs in the disk device of the present embodiment. Here, the information relating to the reliability or life of the disk device is, as described below, that the head, disk, circuit, drive mechanism, or the like of the disk device cannot be used or is likely to be unusable. Information indicating a sign,
Such information is always or timely monitored by the disk device itself.

When an error occurs (201), the content of the error is suddenly lost and a read signal from a specific head is lost.
If it is determined that the disk is damaged, for example, if a break in the head circuit or a crash of the head / disk in the case of a magnetic disk is assumed (202), similar damage occurs on other disk surfaces. Since it is considered highly probable, the data of the other disk surface is promptly saved to another storage device which has been separately set (203), and further, a data configuration not using the defective disk surface ( Rewrite the data to a data structure that newly has redundancy on multiple surfaces excluding the defective disk surface (reconstruction of redundant data 206), and warn the user that the disk device may not be usable Yes (211).

At this time, if the user has constructed a partition in the disk, the configuration may be changed, or if the partition is used as a mirror disk, for example, the mirror disk may be damaged. Warning.

Further, for example, mirroring (RAID-1
In the disk device that has performed the processing of (equivalent), the redundancy configuration is replaced by a parity formula (RAID 3 to RAID 5) in order to compensate for the reduced device capacity due to the inability to use a specific disk surface from the viewpoint of user request or data capacity. Equivalent).

For example, when a disk device having a storage capacity of 10M is used by using four disk surfaces and four heads as shown in FIG.
When recording 5M data from the host device, in data mirroring, 2.5M data is stored on each disk surface, and 5M (data amount) × 2 (mirroring) = 10M (storage of disk device) Capacity), and the disk device uses its entire storage capacity for the amount of data to be recorded.

Here, for example, when an error occurs in the uppermost disk surface and the disk surface cannot be used, the disk device cannot store data by mirroring of 5M data input. However, if an appropriate RAID is selected without adding mirroring and 1/3 parity is added, the required storage capacity is 5M × 5 because the 5M data is divided into three and the parity data is stored.
4/3 = 6.7M, which is within the range of the capacity (2.5M × 3 = 7.5M) that can be covered by other disk surfaces without using the 2.5M capacity of the failed top disk. is there. As described above, if you change the data storage format, even if a specific disk surface becomes unusable,
Input data can be stored in the entire disk device. At this time, the data storage format is changed based on the error information.

Further, the host computer (or user) is notified that the data capacity and the disk configuration have been changed (211).

If the content of the error is that the number of damaged data in a specific disk surface has increased or the error rate has decreased (204) or, for example, in the case of a magnetic disk device, the resistance of the magnetic head has gradually changed. As in the case (205), when it is assumed that the life of the disk surface or the head is approaching, the disk surface and the head are invalidated, and the data is rewritten to a data configuration that does not use the defective disk surface. (Reconstruction of redundant data 206), the user is warned that the disk device may not be usable (211).

If the micro-positioning mechanism of the head is out of order, or if the positioning of a specific head is constantly or averagely delayed (207), the positioning by the initial actuator using the head as a reference head is performed. So that is positioned on the desired track
If the sequence is improved so as to be executed, or if the micro-positioning mechanism of a plurality of heads breaks down, the respective heads are sequentially positioned by driving the actuator to collect and save data (208), and the disk device is provided to the user. Warns that it may become unusable (21
1).

By performing recovery, saving, rebuilding, and warning of data based on such reliability information on the life of the device, it is possible to prevent the disk device from functioning in advance and to avoid data loss. it can.

FIG. 3 shows a configuration example of the disk device according to the present embodiment. A plurality of disks (301) and their driving mechanisms (3
02) for reading and writing data (303)
A mechanism (304) for finely positioning, for example, a piezo element between the magnetic head and the actuator. The mechanism (304) for fine positioning does not need to be a piezo element, and may be a mechanism capable of performing the same function, for example, a mechanism that displaces by applying electrostatic potential or repulsion between electrodes by applying a potential.

As described above, after the head (303) is driven to the approximate position by the actuator, the position of the desired head is adjusted with respect to the servo signal by the micro-positioning mechanism (304), so that a sufficient S / D is obtained. Each head can be moved to a position where the N ratio can be obtained, and recording and reproduction can be performed simultaneously by a plurality of heads.

FIG. 4 shows another example of the configuration of the disk device according to this embodiment. As in FIG. 3, a magnetic head (303) for reading and writing data is provided for a plurality of disks (301) and its driving mechanism (302), and two heads (two groups of 303a and 303b) 303c and 303d). One group includes two or more heads. Each group has an actuator, and 303b and 303c are positioned by the respective actuators. Each of 303a and 303d is corrected by a mechanism (304) capable of minutely positioning the displacement.

That is, when the positioning reference head is fixed, the head does not need to have a minute positioning mechanism. Alternatively, it is not necessary for the head having a positioning error with respect to the reference head to have a minute positioning mechanism. When a group of heads that fall within the allowable error is set as one group, it is possible to omit all the minute positioning mechanisms by positioning the group with an individual actuator. Although the features of the other configuration examples have been described, the heads 303b, 303
This does not deny that an apparatus configuration having a minute positioning mechanism in c is included in the present embodiment.

As described above, the embodiments of the present invention include those having the following configuration examples and functions or functions.

The disk device has a minute positioning mechanism for each head individually or a plurality of actuators. That is, the magnetic disk device of the present invention has a plurality of disk surfaces for recording data and an access to the disk surface. A plurality of heads for recording, simultaneously accessing and recording and reproducing a plurality of disk surfaces,
A mechanism is provided for minutely positioning the heads individually or in groups.

Further, the magnetic disk drive of the present invention comprises a plurality of disk surfaces for recording data and a plurality of heads for accessing the disk surfaces, and a disk for simultaneously accessing and recording and reproducing the plurality of disk surfaces. The apparatus is provided with a mechanism for finely positioning a head individually or for each of a plurality of groups, and has a track pitch of 1 μm or less on a disk surface.

Further, a disk device in which a processing method when an abnormality relating to device reliability or life has occurred is incorporated in the disk device in advance. That is, the magnetic disk device of the present invention includes a plurality of disk surfaces for recording data and a plurality of heads for accessing the disk surfaces, and a disk device for simultaneously accessing and recording and reproducing a plurality of disk surfaces. A disk device provided with a mechanism for finely positioning the head individually or in groups of a plurality of groups, and based on information relating to the reliability or life of the disk device, a data storage method (format (= style) ) And means for protecting the data by changing the access method and disk surface to be used, changing the configuration of redundant data, saving data, issuing a warning, and the like.

Further, the magnetic disk drive of the present invention comprises a plurality of disk surfaces for recording data and a plurality of heads for accessing the disk surfaces, and a disk for simultaneously accessing and recording and reproducing the plurality of disk surfaces. In the device, a disk device having a mechanism for minutely positioning the head individually or for each of a plurality of groups, and a track pitch of 1 μm or less, and based on information on reliability or life of the disk device, There is provided a means for protecting the data by changing the data storage method and access method and the disk surface to be used, changing the configuration of the redundant data, saving the data, giving a warning, and the like.

[0044]

According to the present invention, it is possible to simultaneously access all necessary tracks by using a minute positioning mechanism after each head has its own minute positioning mechanism and performs rough positioning with an actuator. it can.

Further, by having a plurality of actuators, it is possible to simultaneously access all necessary tracks by individually positioning a group of heads within an allowable error.

Further, it is possible to execute an error process for the disk device when an error occurs in information relating to the reliability or life of the disk device.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a specific example of a read operation of a disk device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a specific example of processing contents when an error relating to reliability or life of the disk device of the embodiment has occurred.

FIG. 3 is a diagram illustrating a configuration example of a disk device according to the embodiment;

FIG. 4 is a diagram illustrating another configuration example of the disk device of the embodiment.

[Explanation of symbols]

101 to 112: steps of a flow showing a specific example of read operation 201 to 211: steps of a flow showing a specific example of error processing relating to reliability 301: disk for data recording 302: disk drive Spindle motor 303: Data recording and reproducing head 303a to 303d: Individual data recording and reproducing head 304: Fine positioning mechanism

Continued on the front page F term (reference) 5D042 AA07 BA07 CA02 DA12 EA04 MA15 5D066 BA02 BA08 5D068 AA01 AA02 BB02 EE15 GG24 5D096 NN03 NN05 NN07

Claims (5)

[Claims] A plurality of disk surfaces for recording or reproducing data; a head provided corresponding to each disk surface;
An actuator for accessing the head on the disk surface, comprising: a fine positioning mechanism that finely positions the head for each individual head or for each actuator that operates a plurality of heads collectively; A disk apparatus, wherein after the heads are simultaneously accessed on a plurality of disk surfaces by an actuator, each head is finely positioned on a desired track by the fine positioning mechanism, and data is recorded or reproduced on the plurality of disk surfaces. 2. The disk device according to claim 1, wherein data is protected by changing a storage format of data on the disk surface based on information on reliability or life of the disk device. Disk device. 3. The disk device according to claim 2, wherein the change in the data storage format includes a change in a disk surface to be used, a change in the configuration of redundant data, or a change in the number of head accesses. A disk device characterized by the above-mentioned. 4. The disk device according to claim 1, wherein the data is protected by saving or warning the data based on the information on the reliability or the life of the disk device. 5. The disk device according to claim 1, wherein a track pitch on the disk surface is 1 μm or less.