JPH01251372A - Magnetic disk control device - Google Patents

Abstract

PURPOSE:To facilitate a regular maintenance work by securing an alternate area on a disk, rereading a defective part when this defective part is generated and processing alternately the alternate area. CONSTITUTION:The subject device is provided with a work register 3 for holding a defective address, a work resister 1 for holding an alternate address, a flag 2 for indicating internally the occurrence of an error and a data buffer (in HDC) 4 to be used for carrying out a data copy at the alternate time. Then, based on an error at the time of drive access, the defective part is reread without any instruction from a host, and these data are stored in the data buffer 4, while a using part in the alternate area on the disk is automatically formatted. Then, this alternate part possesses a write mechanism for the data stored temporarily in the data buffer 4, which is equipped with a real time automatic alternate processing function in such a way that the format of the alternate part is automatically performed at the time of generating the defective part, such as a defective track, etc., and a write process of the temporarily stored data is performed in this alternate part. By this method, the working operation in regular maintenance, etc., can thus be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Application Field) The present invention is capable of re-reading and temporarily storing data in the defective part without a command from the host side when a defective part such as a defective track occurs. The present invention relates to a magnetic disk control device having a real-time automatic substitute processing function, which automatically formats a substitute section and writes the data stored at the above-mentioned time to the substitute section.

(Prior Art) Conventionally, when a new defective track occurs during use in a magnetic disk device used in an information processing system,
At that point, retry processing or other error recovery processing is being performed, but the defective track will be artificially assigned to another normal track using an independent test program during subsequent periodic maintenance, etc. Processing (alternative truck processing) work was being carried out. For this reason, in the past, the work required during periodic maintenance increased, resulting in poor workability.

(Problem to be Solved by the Invention) As described above, conventionally, when a new defective track occurs during use, the defective track is checked by an independent test program or the like during subsequent periodic maintenance. 1, there was a problem that workability during periodic maintenance was poor because alternative track processing was performed to allocate to a different track.

The present invention was made in view of the above circumstances, and aims to automate magnetic disk maintenance.
) real-time automatic alternative processing (alternative track processing) in firmware (FW).

It is an object of the present invention to provide a magnetic disk control device that can reduce the complexity of periodic maintenance work and perform periodic maintenance work efficiently and smoothly.

[Structure of the Invention] (Means and Effects for Solving the Problems) The present invention secures an alternative area on the disk, and when a defective area occurs internally during drive access, the defective area is re-read and the disk is re-read. A magnetic disk control device having means for performing alternative processing in the above alternative area, the magnetic disk control device having a defective address (DADR) inside the magnetic disk control device.
and a work register that holds the alternate address (PALT
), a flag (EALT flag) that internally indicates the occurrence of an error, a data buffer used to copy data during substitution, and a command from the host based on an error during drive access. re-reads the defective part and stores the same data in the data buffer, automatically formats the used part in the alternative area on the disk, and writes the data temporarily saved in the data buffer to the substitute part. When a defective part such as a defective track occurs, 1. The data in the defective part is re-read and temporarily saved without any command from the host side, and a replacement part is automatically formatted, and the above data is written to the replacement part. - The configuration is equipped with a real-time automatic alternative processing function that writes and processes saved data, which automates processing for defective tracks and facilitates maintenance work such as periodic maintenance. .

(Example) An embodiment of the present invention will be described below with reference to the drawings.

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

In the figure, 1 to 4 are magnetic disk drives (HDC), respectively.
1, 2, and 34 are registers on the firmware. Among these, ① is a work register that holds the address (PALT) of the next alternative track to be used, and is hereinafter referred to as the PALT register. 2
is an error flag that internally displays an error state such as when the alternative area is full, and is hereinafter referred to as the EALT flag.

A work register 3 holds the address when an error occurs during actual drive access (read/write), and is hereinafter referred to as the DADR register. Reference numeral 4 denotes a data buffer used when reading/writing a disk (DISK), which is also used during alternative processing, and has a predetermined capacity of one sector or more. Further, 5 is an alternative track area provided on the inner circumferential side of the disk (DISK).

FIGS. 2(a) to 2(c) are flowcharts showing a real-time automatic substitution processing routine realized by firmware (FW) in the magnetic disk drive (HDC) in the above embodiment.

Here, the operation of the above embodiment will be explained with reference to FIGS. 1 and 2.

The operation here is divided into the time when the magnetic disk controller (IDC) is powered on and the time when the drive is actually accessed.

When the power is turned on, an alternative area is checked for the disk of the drive to be controlled. The minimum check here is to obtain the start address (PALT) of an available alternative track (step Sl in FIG. 2(a)).

Further, when checking the alternative track start address (PALT), if there is any problem (such as when the alternative track is full), the EALT flag 2 is set (step S2 in FIG. 2(a)).

On the other hand, in actual disk access, a normal read operation (or write operation) is first performed (Fig. 2(c)).
Step S14).

When an error occurs during disk access, it is determined whether the error is caused by the disk media or not. If the error is caused by the disk media, alternative processing is required, so the address is D.A.D.R.
Hold in register 3 (Fig. 2(c) step S15)
．． S1B).

In addition, in the case of errors caused by the media, only errors that can be corrected using ECC and are saved by trying
Perform automatic substitution processing immediately after the command finishes (
FIG. 2(c) Step SL7, 817-823).

Additionally, in the case of an error caused by the media and the data cannot be read even after rewriting, if a command to instruct alternative processing is received from the host immediately after the error ends, the same alternative processing as in the case of a successful retry is performed. (Figure 2 (
b) Step SL1~513).

For alternative processing, the magnetic disk controller (IDC)
This is done via the internal data buffer 4. This alternative processing includes alternative track processing and alternative sector processing, but the basic operation is the same in both cases.

For alternative processing, EALT flag 2 and DADR
From the contents of register 3, it is determined whether the error is caused by the disk medium (step 818 in FIG. 2(c)).

At this time, if there is any error in checking the EALT flag 2, no alternative processing is performed.

However, at this time, no error status is reported to the host.

Also, if the error is caused by the disc media (
That is, when the defective address is set in the DADR register 8 and there is no error in checking the EALT flag 2), first, the data of the defective part that is already held is read out again to the data buffer 4 (
FIG. 2 <C> Step S19).

Next, the track at the address indicated by the PALT register 1, which should be used as an alternative track, is checked. At this time, if the track is already in use or defective, please
Update the address value (PALT) of the ALT register ■,
A similar check is performed for the next track according to the updated address (step 520 in FIG. 2(c)).

If the track is normal, it is formatted as an alternative track. At this time, the data in the data buffer 4 is also written in the same way (step 521 in FIG. 2(C)).

Next, format the defective original track as "defective track 2" and link it with the replacement track. In other words, put the link information of the replacement track in the defective track (
FIG. 2(C) step 522).

Finally, if necessary, verification is performed and the process ends (step 823 in FIG. 2(C)).

As another embodiment, step S19 in FIG. 2(c) above
Since there is no guarantee that data that has been read once can be read again in the above process, if an error occurs during actual drive access (from the host), step 81 (C) in the same figure is executed.
8 to 523) may need to be performed.

Alternatively, it is also necessary to verify the alternative track before performing the process of step S22 in FIG. 2(C) above.

The above-described alternative track process automates the process for defective drives, thereby saving maintenance effort. Additionally, reliability is increased because the number of errors visible to the host may be reduced. In addition, the development cost is extremely low, so it is easy to put it into practical use.

Alternative track processing has been described above, but alternative sector processing can also be automated in the same manner.

[Effects of the Invention] As detailed above, according to the magnetic disk control device of the present invention, an alternative area is secured on the disk, and when a defective area occurs internally during drive access, the defective area can be re-read. The above-mentioned alternative area has a means for performing alternative processing, so that when a defective area such as a defective track occurs, the data of the defective area is re-read and temporarily saved without any command from the host side, and the data is automatically transferred to the alternative area. The configuration is equipped with a real-time automatic alternative processing function that formats the data and writes the data saved in the above-mentioned time to the alternative section, thereby automating the processing of defective tracks and making it easier to perform maintenance operations such as regular maintenance. It can make the work easier.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a flowchart showing the processing flow of the above embodiment. 1...PALT register (work register that holds the address of the next alternative track to be used), 2...EA
LT flag (error flag that internally displays error status)
, 3... DADR register (work register that holds the address of the track where the error occurred during drive access), 4... data buffer, 5... disk (D
Alternative track area within ISK). Applicant's representative Patent attorney Takehiko Suzue 1-IDc data buffer Figure 1

Claims (1)

[Claims] A magnetic disk control device comprising means for securing an alternative area on a disk, and re-reading the defective area when a defective area occurs therein during drive access and performing alternative processing in the alternative area.