JPS59117715A - Data processing system in magnetic disc device - Google Patents

Abstract

PURPOSE:To eliminate apparently a slope by saving once stored information when an amount of alternate track used exceeds a preset limit value and restoring the stored information again after initializing a volume. CONSTITUTION:A discriminating section JA forces a work volume to be set when the amount of alternate track exceeds the limit value of use. When the work volume is set in a magnetic tape device WKMT, a data processing section DA performs saving work SAVE of information to the said volume of a magnetic disc DASD. When the saving of the information is finished, a random access volume is initialized. Then, a format coincident with the slope of a head assembly ASBY is written by setting again a track format so as to initialize the format, allowing to eliminate apparently the slope theta.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data write control method in a magnetic disk device.

As schematically shown in FIG. 1, the magnetic disk device includes a plurality of magnetic disks DK that are rotated as one by a spindle motor SPM, and a magnetic head HD faces the recording surface of each disk.

Each head HD is head assembled! J ASBYi is connected to the drive unit D'V for head positioning.

The marked surface of each Dinuk consists of a plurality of concentric tracks as shown in FIG. 2(a). Each track e.g. 1
The track TR1 is composed of a plurality of records (for example, 64) R1 to R64, as shown in FIG. Each of the records R1 to F64 is an area arranged in parallel along the circumferential direction of the track. And each record -F R1-
As shown in Rh (Q), the first degree second degree. Third gear lug Gl, G2. It consists of G8, Atto V Nueria AA, and Data Area DA.

The index mark 5E01.NDM indicates the physical base point of the track in the circumferential direction, and is the sector mark 5E01. G2. G3 has sector mark 5ECIφ and address area AA, respectively.
Separate by i. Separate address area AA and data area DA. Set to separate data area DA and sector mark. Address area AA is written to indicate the address of each record. When reading and writing information, the index mark I is used to position the head.
NDM and sector mark sge+φ are used, and address area AA is referenced. That is, an index mark INDM is placed on one of the plurality of recording surfaces.

Servo information including the sector mark SEelφ is stored, and the data head is positioned while reading this with the servo head.

By the way, while a magnetic disk drive is used for a long time, the head assemble IJAsBY may be tilted from its original position as shown in FIG. This inclination angle θ increases along the installation radius, and substantially stops increasing after a certain period of time has elapsed, but this period is not constant depending on the device, and O is also not constant. On the other hand, when this tilt occurs, it becomes impossible for the servo head to position the data head at a predetermined position, resulting in read errors.

This may cause a write error. Therefore, the degree of inclination must be constantly monitored, but since θ is small, on-site measurement, and constant monitoring, is actually impossible.

The present invention has been made from this point of view, and it is an object of the present invention to eliminate read/write errors caused by the above-mentioned inclination even if the inclination occurs.

To this end, in the present invention, the occurrence of inclination is monitored by the usage status of the alternate track, and if the usage of the alternate track exceeds the set usage limit, the storage information is temporarily evacuated and then the volume is initialized. If the stored information is restored after the conversion, the skew can be apparently removed.

The present invention will be explained below along with the drawings.

FIG. 8 is a block diagram showing the outline of the data processing device, in which TRL is a track management section, von, M are volume management sections, JA is a judgment section, DA is a data processing section, and DASD
is a magnetic disk device, WKMT is a magnetic tape device, CO
NS indicates the console, D (Sl) indicates the display, and KBD indicates the keyboard.

The track management unit TRLM stores the use limit value of alternate tracks for each of the random access volumes among the volumes that are advantageous to the synutem. This usage limit value can be updated from the console C0N5, and when a new random access volume is set, the usage limit value for that volume can be registered from the console C0NS. Judgment gJA compares the usage amount of the alternate track in the set random access volume with the usage limit value of the corresponding volume in the track management unit TRLM.

The amount of alternate tracks used in a random access volume is determined by the volume content inventory (V
TOe). The judgment unit JA determines whether a work volume is prepared if the relationship between the usage limit value and the replacement track usage is a specific relationship, for example, the latter exceeds the former, and if it is not prepared, the conso wcONs Outputs a message to prompt the user to set the work volume. Further, when a work volume is set in the magnetic tape device -wffirr, it is directly notified to the data processing unit DA. Data processing unit I) When A receives the notification, it performs an information backup operation S on the corresponding volume of the magnetic disk device DASD.
Perform A' and 'E. This is saved to the work volume of the magnetic tape device WKMT. When the information saving work is completed, the random access volume is initialized. This is due to the gap Gl in FIG. 2(C).
, G2. G3 is to reset the track former consisting of address area AA and data area DA. In this case, the index mark NDM exists on the servo surface.

Servo information including sector mark SECM is not initialized. By initializing this track format, a format that meets the concerns of the head assembly ASBY has been written, and the inclination θ has apparently been removed from data processing! , DA performs the information restoration work LOAD when the initialization of the random access volume is completed. This is done by writing the information saved in the work volume to the initialized random access volume.7 As explained above, according to the present invention, the degree to which the head assembly is tilted is determined based on the usage of alternate tracks. When the volume exceeds a certain specified value, the volume's track at V7. Since the initialization at this time includes the slope, the slope can be substantially absorbed. Therefore, the head and the deine can be synchronized, reducing the error rate.

FIG. 1 is a side view showing an overview of a magnetic disk device, FIG. 2 is an explanatory view showing the format of a data recording surface, and FIG. 3 is a block diagram showing an overview of a data processing device according to the present invention.

In the figure, ■NDM is an index mark, SECM is a sector mark, Gl, G2. G3 is the gap, AA is the address area, DA is the data area, TRLM is the track management section, VOLM is the volume management section, JA is the judgment section, D
A indicates a data processing section.

Figure 1 Figure 2 ) Figure 3 11 meeting LQA U

Claims (1)

[Claims] A magnetic disk device that writes and reads information according to a track format set for each track, and is controlled so that when a write error occurs during writing of information, the information is written to a predetermined alternate track. a track management unit that manages the use limit value of alternate tracks for each volume, and a volume management unit that checks the usage amount of the alternate track in each volume when using the volume and compares it with the usage limit value, When the usage amount of the alternate track reaches a certain value with respect to the usage limit value, the volume management unit saves the stored information to a work volume prepared in advance, and then changes the track format to that volume. A data processing method characterized by initializing the work volume and then restoring the information on the work volume to the initialized volume.