JP2009140590A - Method of controlling magnetic disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent adjacent track interference associated with high density of a disk medium in a magnetic disk drive, though there is such a problem that the effect of ATT (interference between adjacent tracks) is caused by expanding storage capacity due to high density of a magnetic disk medium. <P>SOLUTION: In the magnetic disk drive in which capacity clip is performed, track interval is set arbitrarily by a command, it controls data access for the magnetic disk medium that track intervals are provided on the magnetic disk medium, reserved data is protected from ATI by leakage luminous flux when concentrated write-in for the same track is performed, and a fault rate of the magnetic disk drive can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control method for suppressing the influence of interference between adjacent tracks caused by increasing the density of a magnetic disk medium in a magnetic disk device.

  In recent years, magnetic disk devices have been increased in recording density of magnetic disk media in order to reduce the size for mounting on small terminals such as portable terminal devices and to increase the capacity for storing large-capacity data such as digital images. Technology is being sought.

  For example, it is possible to improve the recording density by improving the linear recording density in the circumferential direction of the track of the magnetic disk medium, increasing the density between tracks by narrowing the track interval (track pitch), and narrowing the magnetic head width. It has been.

  However, as described above, by increasing the storage capacity by increasing the density of the magnetic disk medium, writing to the magnetic disk medium is easily influenced by interference between adjacent tracks (ATI) due to leakage magnetic flux from the magnetic head. There is a problem of becoming.

  First, the above-mentioned ATI (Adjacent Track Interference) is adjacent to a target track when data is intensively written on the same track at the time of data writing of a magnetic disk device equipped with a magnetic disk medium having a narrow track interval. Magnetic flux leaks from the side of the magnetic head to the track. The data of adjacent tracks is affected by this leakage magnetic flux over and over, and the data is gradually destroyed, eventually becoming unreadable and causing a failure of the magnetic disk unit. Sure.

  For example, an OS (Operating System) generally stored in a magnetic disk device operates to write log information to the magnetic disk every time it is shut down. At that time, the new log information is overwritten on the previous log information of the same track.

  ATI is generated by repeatedly performing this concentrated write operation on the same track.

  The present invention has been made to solve such a problem, and an object thereof is to suppress the influence of ATI and protect data in a magnetic disk device.

  Terminal automatic equipment such as an automatic teller machine (hereinafter referred to as ATM) and industrial machine tools do not require a large-capacity magnetic disk device, so by limiting the capacity of a large-capacity magnetic disk device, The capacity is used smaller than the original magnetic disk device (hereinafter referred to as a capacity clip).

  In the present invention, a track interval can be thinned by performing the above-described capacity clip in a magnetic disk having firmware that can provide an arbitrary track interval by a command.

  The track interval can be set with an arbitrary track interval by a command that can provide a track interval suitable for the intended use.

  As described above, by providing an arbitrary track interval, for example, when writing data such as log information, even if intensive data writing is performed, adjacent tracks are unnecessary areas and there is no data. Abnormalities can be avoided.

  Further, in a magnetic disk device that has performed a capacity clip, a track that cannot be normally accessed due to a restriction can be used as a replacement area.

  According to the present invention, the influence of the ATI of the magnetic disk apparatus can be suppressed.

  Further, in a magnetic disk device that has performed a capacity clip, a track that is not normally accessible can be used as a replacement area.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the magnetic disk medium, as shown in FIG. 1, track 0, track 1, track 2 and servo track information are physically written from the outer periphery to the inner periphery.

  Further, in the circumferential direction of each track, there are blocks called sectors which are the minimum access units of the magnetic disk medium, and logical block addresses (address numbers) are assigned to all sectors in order.

  In the control by the firmware of the present invention, the track interval can be arbitrarily set and changed by a command, and the track interval can be freely changed according to the use application.

  As shown in FIG. 2, this command can set a command table with track intervals depending on the application, such as one physical track, two tracks, and three tracks.

  FIG. 3 is a flowchart showing the operation of the firmware for setting an arbitrary track interval by a command according to the present invention and performing data access.

  For example, it is assumed that the firmware is set in the command table 1 of FIG. 2 and data is written to “addresses 100 to 199” this time.

  The host computer attempts to write data to “addresses 100 to 199” to the magnetic disk device to store data.

  Here, the firmware of the magnetic disk device converts “addresses 100 to 199” to “addresses 200 to 299” using the command table 1 and writes the data to “addresses 200 to 299” of the magnetic disk medium.

  From the host computer, it appears that the data has been written at “addresses 100 to 199” of the magnetic disk medium, but actually, the magnetic disk medium is not “addresses 100 to 199” of track 1 but “addresses 200 to 200 of track 2”. 299 ".

  FIG. 4 shows a case where data is written to “addresses 100 to 399” by the logical block address conversion by the firmware as described above.

  The host computer tries to write data to “addresses 100 to 399”.

  The firmware of the magnetic disk device converts “addresses 100 to 399” according to the command table 1 and provides track intervals to “addresses 200 to 299”, “addresses 400 to 499”, and “addresses 600 to 699”. ].

  As a result, data appears to be written in tracks 1 to 3 “addresses 100 to 399” on the magnetic disk medium from the host computer, but on the actual magnetic disk medium, “address 200 of track 2” is displayed. To 299 ”,“ address 400 to 499 ”of track 4, and“ address 600 to 699 ”of track 6 are written.

  In this way, by performing the conversion control of the logical block address by the firmware, the data on the magnetic disk medium is written with an interval so as to be thinned out one track at a time.

  At this time, the entire surface of the magnetic disk medium can be used by reassigning the logical block address to the track that has been thinned out again with track 1 and track 3, and the capacity of the magnetic disk device itself can be used without change.

  Further, when capacity clipping is performed with a normal firmware-controlled magnetic disk device, only the area from the outermost periphery to where the capacity is limited is specified as shown in FIG.

  However, in the case of a magnetic disk device that performs logical block address conversion control by firmware as described above, unused tracks and tracks that are actually used can be thinned out alternately as shown in FIG.

  Capacitance clipping is performed on the above magnetic disk device that controls the conversion of logical block addresses by firmware, and even if data is centrally written by providing an area without data between tracks, adjacent tracks are not Since data is not written, data destruction can be prevented without being affected by ATI.

  In addition, when there is a defective area, the track that has been thinned out at this time can also be used as a spare area for automatic replacement processing of information in the defective area as an alternative treatment. .

FIG. 3 is an explanatory diagram of a general magnetic disk medium. An example of a firmware command table providing an arbitrary track interval. Flowchart 1 for changing a logical block address. Flowchart 2 for changing a logical block address. Explanatory drawing of the magnetic disc medium at the time of a capacity | capacitance clip. Explanatory drawing at the time of capacity | capacitance clip in the magnetic disc medium which can change a logical block address.

Explanation of symbols

  0-9 ... track number, 0-999 ... address number.

Claims (3)

  A magnetic disk apparatus having a firmware control system capable of accessing data at an arbitrary track interval in a magnetic disk apparatus mounted with a magnetic disk medium to which servo track information is assigned.   2. A magnetic disk apparatus having firmware control according to claim 1, wherein a track interval can be arbitrarily set and changed by a command.   3. In a magnetic disk device having track intervals according to the command of claim 2, the storage capacity is limited to a capacity smaller than the original value, and a track that is no longer normally accessible and can be set and used as a replacement area. A magnetic disk device characterized by the above.

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