JP2001076435A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability of important data, to facilitate accessing to the important data wherever a recording head is at any position on the inner peripheral side or outer peripheral side, and further to improve reliability after alternation processing of a faulty track. SOLUTION: A recording area 2 of a magnetic disk 1 is provided with a high reliability area 6 decreased in error rate at the time of recording and reproducing data by decreasing a track recording density compared with other areas, and further increasing a re-write frequency, in the middle circumferential part of the disk and important data such as a file system, user data are recorded in this high reliability area 6, and moreover, the area is allocated as a replacement of a faulty track which may occur later.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, and more particularly to an improvement in stability of operation of the drive and reliability of data to be recorded and reproduced.

[0002]

2. Description of the Related Art An example of a recording method of a conventional magnetic disk drive is disclosed in Japanese Patent Application Laid-Open No. 61-255564.

As shown in FIG. 4, in the conventional data recording method of the magnetic disk drive, a recording area 42 of a magnetic disk (magnetic disk plate) 41 is divided into a plurality of coaxial zones (areas) 45. The number of storage bits per track is smaller in the zone inside these zones (areas). As a result, the linear recording density is made substantially uniform over the entire area of the magnetic disk plate.

In FIG. 1, reference numeral 43 denotes a sector, and reference numeral 44 denotes servo position information.

Japanese Patent Application Laid-Open No. 57-301 discloses an example in which data to be recorded / reproduced by a conventional magnetic disk drive is made highly reliable.
No. 53.

In this conventional magnetic disk drive, a backup data area is provided especially in the magnetic disk drive, and data to be backed up is stored in both the normal data area and the backup data area, thereby improving the reliability of the system. Is being planned.

[0007]

In recent years, the use of magnetic disk drives as image data storage media has been increasing. At this time, the data stored in the magnetic disk device can be roughly classified into two types: important data such as a file system managed by a host controller and image data (normal data) whose transfer rate is important. It is also conceivable to have a difference in the reliability of the two types of data.

However, the above-mentioned Japanese Patent Application Laid-Open No. 61-25 / 1986
The conventional system disclosed in Japanese Patent No. 5564 has the following problems.

The first problem is that important data may have an error at the same frequency as normal data.

[0010] The reason is that the linear recording density of the entire area of the magnetic disk plate is substantially uniform, so that important data and ordinary data are recorded without distinction.

A second problem is that access to important data may take time depending on the head position.

The reason is that important data such as a file system is often recorded on the outer peripheral portion, so that when the head is located on the inner peripheral portion, it takes time to access the outer peripheral portion.

Next, in the conventional system disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 57-30153, since a backup area is provided especially in a magnetic disk device, there is a problem that the system becomes complicated and costs increase. is there.

An object of the present invention is to provide a magnetic disk drive characterized by improving the reliability of important data.

Another object of the present invention is to average the time required to access important data such as a file system which is frequently accessed when the recording / reproducing head is at any position on the inner and outer peripheral sides. It is another object of the present invention to provide a magnetic disk drive characterized in that:

Another object of the present invention is to provide a magnetic disk drive characterized by improving the reliability of a defective track after replacement processing.

[0017]

According to the magnetic disk drive of the present invention, the linear recording density is reduced in the recording area (2 in FIG. 1) of the magnetic disk plate as compared with other areas, and the number of retries is further reduced. And a high-reliability area (6 in FIG. 1) having a reduced error rate at the time of data recording and reproduction is provided in the center part of the disk.

Important data such as a file system and user data are recorded in the high-reliability area, and are assigned as a substitute for a subsequent defective track.

Therefore, the reliability of the important data is improved, the access to the important data is easy when the recording / reproducing head is at any position on the inner peripheral side or the outer peripheral side. The effect of improving the performance is obtained.

[0020]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a disk surface of a magnetic disk drive according to an embodiment of the present invention.

In FIG. 1, a recording area 2 of a magnetic disk (magnetic disk plate) 1 is composed of tracks concentrically arranged from an outer peripheral portion to an inner peripheral portion for recording and holding magnetization data. Zone 5 is divided into a plurality of coaxial areas. Although the magnetic disk 1 is always rotating at the same angular velocity, the recording / reading frequency of the magnetization data decreases as the zone moves from the outer peripheral zone to the inner peripheral zone, and in the entire recording area 2, Since the linear recording densities are substantially uniform, the error rates are substantially equal.

At this time, by lowering the linear recording density of a certain zone 6 from the linear recording density of another zone and further increasing the number of retries, the zone 6 becomes a highly reliable high reliability area.

In the figure, 3 is a sector and 4 is servo position information.

FIG. 2 is a block diagram showing a magnetic disk drive including the magnetic disk shown in FIG.

In the figure, a CPU (central processing
When a data write command (or data read command) is given to the magnetic disk device 33 from the unit 35, the controller 24 of the magnetic disk device 33 sends the recording data from the CPU 35 or another storage device 36 via the external bus 34. And the address information for recording the recording data (or only the address information for reading the recording data). The controller 24 sends the data to the read / write channel 21,
The address information received from U35 is sent to the microprocessor 26. The microprocessor 26 converts the address information into a physical address of the magnetic disk 29, sends the physical address information to the read / write channel 21, and converts the position control information of the VCM (voice coil motor) 31 into an SPM (spindle motor). 30 and an SPM / VCM driver 32 that drives the VCM 31. The read / write channel 21 supplies a data write electric signal to the read / write amplifier 25 at a read / write frequency defined uniquely with the physical address based on the received physical address information.
Records magnetization data on the magnetic disk 29 (or reads magnetization data from the magnetic disk 29).

Here, when recording at the address corresponding to the high-reliability area zone (or reading from the address corresponding to the high-reliability area zone), the microprocessor 26 sets to increase the number of retries as compared with the other zones. The read / write channel 21 sets the read / write frequency lower than other zones.

As described above, in the above embodiment, when data is read from or written to the magnetic disk 29, the CPU
When receiving an address corresponding to the high reliability area from 35, the read / write channel 21 records data on the magnetic disk 29 (or reads data from the magnetic disk 29) at a lower frequency than other zones, and further reads data. Since the number of retries during writing has been increased,
It is possible to reduce the error rate of the high reliability area zone. Here, by recording the important data in the high-reliability zone, the reliability of the high-reliability data is improved. In addition, by assigning a track in the high-reliability area zone to a replacement track for a bad track, the frequency of the replacement track becoming a bad track again decreases, so that the reliability after the replacement process is improved.

In the above-described embodiment, the method in which the CPU 35 manages the logical address of the high-reliability area zone has been described. However, a method of newly preparing a command for identifying important data and other data may be considered. In this case, when the magnetic disk device 33 receives a read / write command to which the important data identification command data is added from the CPU 35, the microprocessor 26 accesses the magnetic disk 29 with the physical address of the high-reliability area zone, and transfers the important data. It becomes possible to record in the high-reliability area zone.

As another embodiment of the present invention, a method of providing a high-reliability region in a middle peripheral zone of a magnetic disk plate can be considered. In this embodiment, by providing the high-reliability area zone in the middle part, it is possible to obtain an effect that the important data can be easily accessed when the recording / reproducing head is at any position on the inner and outer peripheral sides.

As another embodiment of the present invention, as shown in FIG. 3, a method of providing a highly reliable area 14 in each of a plurality of zones 13 of a recording area 12 of a magnetic disk (magnetic disk plate) 11 is also possible. Conceivable. In the figure, a part of a track constituting each zone 13 is configured as a highly reliable area track 12. Reference numeral 15 denotes servo position information.

As described above, in this embodiment, since the high-reliability area is provided in each zone, the high-reliability area track is assigned to the alternative track of the defective track, so that the alternative track becomes the defective track again. Since the frequency is reduced, the reliability after the replacement processing is improved, and further, since the replacement track is located near the defective track, an effect that the access to the replacement track is facilitated is obtained.

Further, as another embodiment of the present invention, in a magnetic disk drive in which recording and reproducing heads are formed on both sides of a magnetic disk plate, a magnetic head having the most sensitive head among the heads is mounted. There is also a method of providing a highly reliable area in a disk plate.

[0034]

As described above, the present invention has the following effects.

The first effect is that the reliability of important data is improved. The reason is that important data is recorded in the high-reliability area zone. The second effect is that it is possible to easily access important data. The reason for this is that the high-reliability area zone is located in the middle part of the magnetic disk plate. A third effect is that the reliability of the defective track after replacement processing is improved. The reason is that the high-reliability area track is assigned to a substitute track for the defective track.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a recording area of a magnetic disk according to an embodiment of the present invention.

FIG. 2 is a block diagram of a magnetic disk drive including the magnetic disk shown in FIG.

FIG. 3 is a diagram illustrating a recording area of a magnetic disk according to another embodiment of the present invention.

FIG. 4 is a diagram illustrating a recording area of a conventional magnetic disk.

[Explanation of symbols]

 Reference Signs List 1 magnetic disk 2 recording area 3 sector 4 servo position information 5 zone 6 zone (high reliability area) 11 magnetic disk 12 recording area 13 zone 14 track (high reliability area) 15 servo position information 21 read / write channel 23 buffer RAM 24 controller 25 Read / write amplifier 26 Microprocessor 29 Magnetic disk 30 SPM (spindle motor) 31 VCM (voice coil motor) 32 SPM / VCM driver 33 Magnetic disk device 34 External bus 35 CPU 36 Other storage device 41 Magnetic disk 42 Recording area 43 Sector 44 Servo position information 45 zones

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D031 AA04 EE07 FF05 FF07 HH01 HH11 5D044 BC01 CC04 DE62 DE64 DE76 DE92 EF06 GK14

Claims (6)

[Claims] 1. A magnetic disk drive for recording / reproducing data, wherein the magnetic disk drive has a highly reliable area having a lower linear recording density than other areas in the disk. 2. The magnetic disk drive according to claim 1, wherein the high-reliability area is arranged in a middle part between an outer peripheral part and an inner peripheral part of the disk. 3. The magnetic disk drive according to claim 1, wherein the high-reliability area is assigned as a substitute track for a subsequent defective track. 4. A magnetic disk device for recording / reproducing data, wherein the linear recording density is reduced as compared with other areas in the disk, and the number of retries is increased as compared with other areas in the disk. A magnetic disk drive having a highly reliable area. 5. The magnetic disk drive according to claim 4, wherein said high-reliability region is arranged in a middle part between an outer peripheral part and an inner peripheral part of the disk. 6. The magnetic disk drive according to claim 4, wherein the high-reliability area is assigned as a substitute track for a subsequent defective track.