JP2000311452A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the patrol of all surfaces of magnetic media and to reduce the load of a host controller and to attain the maintainability of the data of all sectors by providing a controller verifying all sectors self-startingly regardless of the presence or absence of the instruction of the host controller. SOLUTION: An interface circuit part 5 which received the control signal of write or read or the like executes a write and read operation in a sector unit by controlling a head and disk assembly 1 while outputting necessary control signal group 102 to the assembly 1. When an access is not present and a magnetic head 3 is positioned on tracks to which sectors of final access belong and they are held in these state, since microdust is accumulated between the head 3 and the magnetic media 2, there is a possibility for incurring head crashes being read impossible states. A controller 4 executes all surface patrolling seeks performing verifying operations in fixed time intervals in order to avoid these head crashes.

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 a magnetic disk drive for self-starting data security.

[0002]

2. Description of the Related Art In order to increase the surface density of a magnetic disk, it is necessary to reduce the distance between a magnetic head and a magnetic medium. However, if this occurs, the probability of a head failure due to micro dust between the head and the medium increases. Since the micro dust is collected and deposited near the magnetic head when the magnetic head stays at a fixed position for a long time, it is preferable to perform a seek operation for moving the magnetic head. This is the so-called patrol seek, and systems for adding this patrol seek function are increasing.

[0003] A magnetic disk drive has also been proposed in which the magnetic disk drive itself carries out patrol seeking at regular time intervals. For example, a magnetic disk device disclosed in JP-A-5-74080 is used. In some cases, a verify function is added at that time.

[0004]

With the recent technological innovation, the capacity of magnetic disk drives has been increased and the product cycle has been accelerated. Therefore, in many cases, the system such as the host controller or the OS cannot keep up with the increase in the capacity of the magnetic disk device, or uses a large-capacity magnetic disk device with a small capacity for the convenience of the user. In such a case, in the patrol seek as a function of the system as described above, the access range is limited, and the entire surface of the magnetic medium cannot be patroled. Further, the system side, including the patrol seek itself, requires a large burden on the system side, such as the necessity of changing the system side setting regarding the patrol seek every time the generation of the magnetic disk device is changed.

In the above-mentioned conventional technology for the magnetic disk drive, the entire surface cannot be patroled or verified due to the convenience of the system. The above prior art is
This is because the magnetic head is merely moved by a predetermined value in accordance with the control of the system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a self-starting overall verification function, which also serves as an overall patrol of a magnetic medium. It is an object of the present invention to provide a magnetic disk device which ensures the integrity of data.

[0007]

According to a first aspect of the present invention, there is provided a magnetic disk drive having at least one magnetic disk medium and a magnetic head. A control device is provided that verifies all sectors in a self-starting manner regardless of the presence or absence.

In this manner, all sectors are self-verified by the magnetic disk device, and this is also the entire surface patrol. Therefore, there is no possibility that the patrol range is limited as in the case of the patrol activated by the host controller. The accumulation of micro dust can be avoided, and data integrity is improved. Also, the burden on the system side is reduced.

According to a second invention of the present application, in the magnetic disk drive of the first invention of the present application, when the control device detects a correctable read error by a verify operation, the sector is automatically replaced. Features. According to the second aspect of the present invention, the burden on the host control device is reduced, and data integrity is improved.

[0010] The third invention of the present application is a magnetic disk drive according to the first invention of the present application or the second invention of the present application.
When the control device detects an uncorrectable read error by a verify operation, the control device reports the sector to a higher-level control device. According to the third invention of the present application, data integrity is further improved.

Further, the fourth invention of the present application relates to the first to third applications of the present invention.
In the magnetic disk drive of the invention, the verifying operation is performed at fixed time intervals. According to the fourth invention of the present application, the possibility of obstruction of control by the host control device is reduced, and accumulation of micro dust can be efficiently avoided.

Further, the fifth invention of the present application relates to the first to fourth inventions of the present application.
In the magnetic disk drive of the present invention, every time each sector is verified by the verify operation, the presence / absence of access by the upper control device is checked, and when the control signal of the higher control device comes in, the verify operation is temporarily stopped. It is characterized in that the control is interrupted and the control is transferred to the host controller. According to the fifth aspect of the present application, accumulation of micro dust can be efficiently avoided without hindering control by the host control device.

According to a sixth aspect of the present invention, in the magnetic disk drive according to the fifth aspect of the present invention, the control device has a memory and stores a position of a magnetic head when a verify operation is interrupted. The verify operation is restarted from the stored position. According to the fifth aspect of the present invention, all sectors can be efficiently verified.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a magnetic disk drive according to the present invention will be described below with reference to FIGS. FIG. 1 is a schematic block diagram of a magnetic disk device according to the present invention. The magnetic disk device according to the present embodiment relates to an HDA 1 including a magnetic disk medium 2 and a magnetic head 3 that seeks the medium, and relates to the present invention. It comprises a control device 4 that is a source of the verify operation, and an interface circuit unit 5 that receives a control signal and sends out a control signal of the HDA 1. Control device 4 and interface circuit 5 and interface circuit 5 and HDA1
, A control signal group 101 and a control signal group 102 are communicated. Although not shown, the interface circuit unit 5 is also accessed from a higher-level control device and receives a control signal of the higher-level control device.

With the above configuration, the interface circuit unit 5 that has received a control signal for writing, reading, etc.
Sends out the necessary control signal 102 to control HDA1,
Operations such as writing and reading are performed in sector units.
However, this operation by the host controller is not always executed, and when there is no access, the magnetic head 3 is positioned on the track to which the last accessed sector belongs. However, if this state continues, micro dust is accumulated between the magnetic head 3 and the magnetic disk medium 2, which may lead to a head crash in a state where reading is impossible. Therefore, in order to avoid a head crash, the control device 4 performs the entire patrol seek accompanied by the next verify operation at regular time intervals.

FIG. 2 is a flowchart showing an overall patrol operation according to the present embodiment. This operation is performed for each sector under the control of the control device 4. As shown in the figure, when the interface circuit unit 5 is not accessing the higher-level control device in the access waiting state 21, the control device 4 transmits the control signal 101.
Is transmitted to the interface circuit unit 5 to start a patrol operation (23). First, a correctable read error is detected 24, and when a correctable read error is detected, a process of replacing the sector in which the error has occurred is performed. Perform 25 and return to the original state (28). Next, an uncorrectable read error is detected 26. If an uncorrectable read error is detected, an error report 27 to the higher-level control device is made and the process returns to the original state (28). If no error is detected, the process returns through the error processing process (28). The above operation is performed for one sector, and at the time of the operation 28 for returning to the original state, the magnetic head 3 is moved to the next sector, and returns to the first access waiting state 21 again to check whether or not the host controller has accessed. I do. When there is access from the host controller,
The current position of the magnetic head 3 is stored in a memory in the control device 4 and an instruction from the higher-level control device is executed (2).
2) After the command is executed, the magnetic head 3 is moved to a position in the memory, and the above operation is restarted from that sector.

As described above, the entire surface of the magnetic disk medium 2 is
Patrol is performed with the verify operation, and access from the host controller can be accepted during this operation.

[0018]

As described above, in the magnetic disk drive of the present invention, all sectors are self-verified by the magnetic disk drive and the entire surface is patrolled. Accumulation can be avoided, data integrity is improved, and the burden on the system is reduced.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 HDA (head disk assembly) 2 magnetic disk medium 3 magnetic head 4 control device 5 interface circuit unit 101 control signal group 102 control signal group

Claims (6)

[Claims] 1. A magnetic disk drive having at least one magnetic disk medium and a magnetic head, comprising a control device for self-starting verification of all sectors irrespective of an instruction from a host control device. Characteristic magnetic disk drive. 2. The magnetic disk drive according to claim 1, wherein, when the control device detects a correctable read error by a verify operation, the sector is automatically replaced. 3. The magnetic disk according to claim 1, wherein, when the control device detects an uncorrectable read error by a verify operation, the sector is reported to a higher-level control device. apparatus. 4. The magnetic disk drive according to claim 1, wherein the verifying operation is performed at predetermined time intervals. 5. Every time each sector is verified by the verify operation, the presence / absence of access by a higher-level control device is checked. When a control signal of the higher-level control device is received, the verify operation is suspended. 5. The magnetic disk drive according to claim 1, wherein control is transferred to a host controller. 6. The control device according to claim 5, wherein the control device has a memory and stores a position of the magnetic head when the verify operation is interrupted, and resumes the verify operation from the stored position. The magnetic disk device according to the above.