JP3552031B2 - Magnetic disk drive and retry control method thereof - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic disk device, and more particularly, to a magnetic disk device, a retry control method, and a retry control program which can appropriately set the number of retries and retry processing when a read / write request including a substitute sector occurs. Related to the recording medium.
[0002]
[Prior art]
In a conventional magnetic disk device, generally, when a read operation of a sector fails and the sector can be read by retry, the read data is transferred to the host system, and then the sector is automatically read. It may be reassigned to an alternate sector.
[0003]
If the sector cannot be read even after retrying after the sector read operation has failed, the sector is registered as a reassignment candidate sector in a table inside the magnetic disk device, and then a write request is issued to the sector. At times, a reassignment to an alternative sector may be automatically performed.
[0004]
Furthermore, when a write operation of a sector fails while the write cache function is enabled, the sector may be automatically reassigned to an alternative sector after notifying the host system of the normal completion of the write. is there. When an error occurs during reading / writing of a sector, a fixed retry is always performed.
[0005]
[Problems to be solved by the invention]
As shown in FIG. 4, when an error occurs during a read / write operation in a certain sector and the sector is reassigned to an alternative sector, the subsequent read / write operation including the sector will continuously read / write the sector. Therefore, in addition to the read / write operation not including the replacement sector, a rotation waiting time always occurs.
[0006]
Alternatively, as shown in FIG. 5, when there is no substitute sector on the track where the read / write request has occurred, it is necessary to seek to the track where the substitute sector exists, and a seek time is further required.
[0007]
As described above, in the conventional magnetic disk drive, when a series of sectors in which a read / write request has occurred includes an alternate sector, and a read / write error occurs in any of the sectors, a normal retry processing time is required. In addition, since a rotation waiting time and a seek time to a substitute track occur, the processing time increases, and as a result, the throughput between the host system and the magnetic disk device deteriorates. That is, when the application to the AV application of the magnetic disk device which is increasing in recent years is considered, it is expected that the video / audio is interrupted.
[0008]
The increase in the retry processing time at the time of reading / writing causes deterioration of the throughput between the host system and the magnetic disk device. When the magnetic disk device is used for AV, recording / reproducing of video / audio data cannot be performed in time. Could cause that.
[0009]
In view of such a situation, the technical problem of the present invention is to reduce the throughput between the host system and the magnetic disk device by reading / writing a track including no alternative sector and reading / writing a track including the alternative sector. It is to secure the same level with writing.
[0010]
[Means for Solving the Problems]
According to the present invention, retry control means for appropriately setting retry processing when a defective sector is reassigned to the same track, and appropriately setting retry processing when a defective sector is reassigned to another track. A retry control unit, wherein when the received read / write command includes an alternative sector, the retry control unit sets an offset value of the recording / reproducing head, and an error occurs in the read / write operation. If an error occurs, the recording / reproducing head is offset by the set offset value until the offset value becomes maximum or the read / write operation ends normally. A magnetic disk drive characterized by being repeatedly executed is obtained.
[0011]
According to the present invention, when a defective sector is reassigned to another track, retry control means for appropriately setting retry processing, and a host interface control unit for receiving and mediating a read / write command from the host system And an alternative sector management table storing information to be searched to determine whether or not the received read / write instruction includes an alternative sector. If an error includes an alternative sector, set the offset value of the recording / reproducing head, determine whether an error has occurred in the read / write operation, and set the recording / reproducing head if an error has occurred. The offset value is maximized, or the read / write operation is Always until the end of the magnetic disk device is obtained, characterized by repeatedly executed.
[0012]
According to the present invention, there is further provided a retry control step of appropriately setting retry processing when a defective sector is reassigned to the same track, and a host interface control step of receiving and mediating a read / write command from the host system. Searching the alternative sector management table to determine whether the received read / write instruction includes an alternative sector. In the retry control step, the received read / write instruction When a sector is included, an offset value of the recording / reproducing head is set, and it is determined whether or not an error has occurred in the read / write operation. Offset by the offset value, the maximum offset value, or read / write operation Until successful, retry control method for a magnetic disk device characterized by repeatedly executed is obtained.
[0013]
Further, according to the present invention, when a bad sector is reassigned to another track, a retry control step of appropriately setting a retry process, and a host interface control for receiving and mediating a read / write command from a host system And a search step of searching an alternative sector management table to determine whether or not the received read / write instruction includes an alternative sector. In the retry control step, the received read / write instruction If an error includes an alternative sector, set the offset value of the recording / reproducing head, determine whether an error has occurred in the read / write operation, and set the recording / reproducing head if an error has occurred. The offset value is maximized, or a read / write operation is performed. Until successful, retry control method for a magnetic disk device characterized by repeatedly executed is obtained.
[0014]
Further, according to the present invention, a recording medium on which a program for executing the retry control method of the magnetic disk device is recorded is obtained.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a magnetic disk device and a retry control method thereof according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0017]
[Embodiment 1]
FIG. 1 shows a block diagram of a magnetic disk drive according to Embodiment 1 of the present invention.
[0018]
The magnetic disk device according to the embodiment of the present invention includes an alternative sector management table 2, a retry control unit 3, an SPM / VCM (spindle motor / voice coil motor) control unit 4, an arithmetic processing control unit 5, a host It has an interface control unit 6, a data read / write control unit 7, and a magnetic medium 8.
[0019]
Here, the read / write control unit 7 reads / writes a magnetic signal from / to the magnetic medium 8. The SPM / VCM control unit 4 controls the rotation of the magnetic medium through the SPM and controls the positioning of the magnetic head through the VCM. The host interface control unit 6 controls a communication protocol with the host system 1. All of these operations are performed under the control of the arithmetic processing control unit 5.
[0020]
Next, the retry control method according to the first embodiment will be described by describing the operation of the magnetic disk device with reference to the flowchart of FIG.
[0021]
First, when the host system 1 issues a read / write command, the command is accepted by the host interface control unit 6 (step S11).
[0022]
The replacement sector management table 2 is searched to determine whether the received read / write command includes a replacement sector (steps S12 and S13).
[0023]
If the received read / write command includes the substitute sector, the retry control unit 3 sets a retry count (step S14).
[0024]
It is determined whether an error has occurred in the read / write operation (step S15) (step S16).
[0025]
If an error has occurred, the retry control means 3 decrements the retry count (step S17).
[0026]
The process is repeatedly executed until the retry count becomes 0 or the read / write operation ends normally (step S18).
[0027]
[Embodiment 2]
The basic configuration of the magnetic disk device according to the second embodiment of the present invention is the same as that of the first embodiment. However, instead of resetting the retry count, the retry method may be simplified.
[0028]
For example, when an error occurs during data reading, means for repeating the retry operation while offsetting the recording / reproducing head by a certain step width is widely known in general. Increase the offset step width.
[0029]
The retry control method according to the second embodiment will be described by describing the operation of the magnetic disk device with reference to the flowchart of FIG.
[0030]
First, when the host system 1 issues a read command, the command is accepted by the host interface control unit 6 (step S21).
[0031]
The alternative sector management table 2 is searched to determine whether the received instruction is a read instruction including an alternative sector (steps S22 and S23).
[0032]
If the received read / write command includes the substitute sector, the offset value of the recording / reproducing head is set by the retry control means (step S24).
[0033]
It is determined whether an error has occurred in the read operation (step S25) (step S26).
[0034]
If an error occurs, the recording / reproducing head is offset by the value set in step S24 by the retry control means 3 (step S27).
[0035]
The process is repeatedly executed until the offset value becomes the maximum or the data is normally read out (step S28).
[0036]
Further, parameter values inside the magnetic disk device in another retry method are also applied to this.
[0037]
As described above, by increasing the step width for offsetting the recording / reproducing head at the time of reading including the alternative sector, the time spent for retry can be reduced, and the error rescue ability by retry can be maintained.
[0038]
【Example】
Next, the operation of the present embodiment will be described using a specific example.
[0039]
FIG. 4 is an example showing a state where the bad sector “2” and the bad sector “6” are reassigned in the same track. Referring to FIGS. 1 and 4, when a read / write instruction for sector “0” to sector “M” (M is an integer) is issued from host system 1 and accepted by host interface control unit 6, First, the replacement sector management table 2 recognizes that two discontinuous sectors have been reassigned, and the retry control means 3 sets the retry count to "initial retry count value-2".
[0040]
FIG. 5 is an example showing a state in which the defective sectors of the tracks “0” to “N” are reassigned to the alternative tracks. Referring to FIGS. 1 and 5, when a read / write command for track “0” to track “N” (N is an integer) is issued from host system 1 and accepted by host interface controller 6, First, it is recognized from the alternative sector management table 2 that six discontinuous sectors "2", "6", "14", "20", "25", and "28" are reassigned to the alternative track. The retry control means 3 sets a value obtained by subtracting from the initial retry count value by the number of times in consideration of the rotation waiting time and the seek time to the alternative track from the initial retry count value.
[0041]
As described above, even when a read / write request including a substitute sector occurs, a constant throughput can be compensated between the host system and the magnetic disk device by appropriately changing the retry count.
[0042]
It should be noted that the present invention is not limited to the above embodiments, and it is clear that the embodiments can be appropriately modified within the scope of the technical idea of the present invention.
[0043]
Further, in order to execute the retry control method of the magnetic disk device according to the present invention, it is possible to create a program and record the program on a recording medium and distribute the program.
[0044]
【The invention's effect】
According to the present invention, by having the alternative sector management table and the retry control means, the number of retries can be appropriately changed, and the retry process can be appropriately simplified. The data throughput between the disk drive and the magnetic disk drive can be compensated.
[Brief description of the drawings]
FIG. 1 is a block diagram of a magnetic disk drive according to an embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation of the magnetic disk drive according to the first embodiment of the present invention.
FIG. 3 is a flowchart for explaining the operation of the magnetic disk drive according to Embodiment 2 of the present invention;
FIG. 4 is a first specific example of the present invention.
FIG. 5 is a second specific example of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 host system 2 alternative sector management table 3 retry control unit 4 SPM / VCM control unit 5 arithmetic processing control unit 6 host interface control unit 7 read / write control unit 8 magnetic media

Claims (5)

Retry control means for setting retry processing when a defective sector is reassigned to the same track; a host interface control unit for receiving and mediating a read / write instruction from the host system; Having an alternative sector management table storing information to be searched to determine whether or not to include an alternative sector,
When the received read / write command includes an alternative sector, the retry control unit sets an offset value of the recording / reproducing head, determines whether an error has occurred in the read / write operation, and determines whether the error has occurred. Is generated, the recording / reproducing head is offset by the set offset value, and is repeatedly executed until the offset value becomes the maximum or the read / write operation ends normally. Magnetic disk unit. Retry control means for setting retry processing when a bad sector is reassigned to another track; a host interface control unit for receiving and mediating a read / write command from the host system; and a received read / write command Has an alternative sector management table storing information to be searched to determine whether or not an alternative sector is included,
When the received read / write command includes an alternative sector, the retry control unit sets an offset value of the recording / reproducing head, determines whether an error has occurred in the read / write operation, and determines whether the error has occurred. Is generated, the recording / reproducing head is offset by the set offset value, and is repeatedly executed until the offset value becomes the maximum or the read / write operation ends normally. Magnetic disk unit. A retry control step of setting retry processing when a bad sector is reassigned to the same track; a host interface control step of receiving and mediating a read / write instruction from the host system; and a received read / write instruction. A search step of searching an alternative sector management table to determine whether or not to include an alternative sector,
In the retry control step, when the received read / write command includes an alternative sector, an offset value of the recording / reproducing head is set, and it is determined whether or not an error has occurred in the read / write operation. Is generated, the recording / reproducing head is offset by the set offset value, and is repeatedly executed until the offset value becomes the maximum or the read / write operation ends normally. A retry control method for a magnetic disk drive. A retry control step of setting retry processing when a bad sector is reassigned to another track; a host interface control step of receiving and mediating a read / write command from the host system; and a received read / write command A search step of searching an alternative sector management table to determine whether or not includes an alternative sector,
In the retry control step, when the received read / write command includes an alternative sector, an offset value of the recording / reproducing head is set, and it is determined whether or not an error has occurred in the read / write operation. Is generated, the recording / reproducing head is offset by the set offset value, and is repeatedly executed until the offset value becomes the maximum or the read / write operation ends normally. A retry control method for a magnetic disk drive. A recording medium storing a program for executing the retry control method for a magnetic disk device according to claim 3 .

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