JPS6381662A - Magnetic disk control system - Google Patents

Abstract

PURPOSE:To prevent recording contents from being lost by shifting the data contents to a track previously provided as a standby when the number of write times reaches a prescribed number. CONSTITUTION:The track area A2 of a magnetic disk 2 for writing data is read. When the number of times of writing recorded in a sector exceeds a prescribed limit number, a write track address is changed to an alternate destination track address TA, and rewriting is executed. When a decision result not exceed the prescribed limit number, the writing in the track is executed, the number of times of writing is updated, and the value is written in the track area A2. Thus, a magnetic controller 1 is controlled so that writing of the recording contents in the track which is approaching the end of the life is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk, and more particularly to a control method suitable for controlling a magnetic disk using a medium that has a short lifespan in terms of the number of writes.

Regarding magnetic disks, they are treated as having a semi-permanent lifespan, and alternative treatments are implemented only for defective parts during magnetic disk manufacturing. However, due to the high-density writing expected in the future, magnetic disks using materials different from those of conventional media are being developed, and media made of materials that have a lifespan of a number of writes are also being considered. Conventional control methods do not take this media life into consideration.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into account the above-mentioned media lifespan, and with media made of newly developed materials, there is a risk that information in the portions that have reached the end of their lifespan may be lost.

An object of the present invention is to prevent information from being lost due to the above-mentioned problem.

[Means for solving problems]

The above object is achieved by transferring data recorded before the medium reaches the end of its lifespan to another area. To do this, record the data to be written and record the number of writes in a part of the recording area, and when the number of writes reaches a predetermined number, move the data to another area. Just change it.

[Effect]

Generally, when accessing a magnetic disk, a method is used in which defective track information is recorded in a specific track of the magnetic disk and this information is read out and controlled before the disk is accessed. In this case, if a medium with a limited lifetime is used, this track will reach the end of its lifetime first. Therefore, information regarding the presence of a defective track and the number of times of writing is provided in a specific area for each track, and the number of times of writing is written in that area and data is also written.

Further, by recording in that area an alternative track address in the case of a defective track and an alternative track address when the track life has been reached, alternative processing becomes possible.

〔Example〕

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

FIG. 2 is a diagram developed on a plane to explain the relationship between tracks and sectors of a magnetic disk.

In the present invention, each sector is allocated as follows.

(1) A sector that stores the track address that will replace area Al (track O, sector O) next time.

(2) Area A2 (track 0. sector 1 and sector 0 of other tracks) is an area for recording the number of times of writing.

(3) Sector 2 to sector L of track 0 and sector 1 to sector L of track 1 are data write areas.

(4) An alternative track area for each track from track)+1 to track)+n.

(5) Sectors i+1 and m+2 of each track are used as alternative sector areas.

Next, the contents stored in each area will be explained using the embodiments shown in FIGS. 3 and 4.

FIG. 3 shows the contents stored in area A1, where TA is the next replacement destination track address when performing track replacement processing. This area is rewritten when performing track replacement processing.

Figure 4 shows the contents stored in area A2, where CNT is an area that stores the number of writes to the track in question, SAI is an area that stores the replacement source sector address of the defective sector, and the replacement destination is the sector address. L+1. Similarly, SA,
is also the replacement source sector address of the defective sector, and the replacement destination is sector address i+2. TA is an alternative destination track address to which the data of the track is transferred when the number of writes (CNT) to the track reaches a certain value.

Next, data writing processing will be explained using the embodiment shown in FIG. First, prior to data writing, area A2 of the track in which data is to be written is read. The number of writes (CNT) described above is recorded in this sector, and it is determined whether or not this value meets a preset limit value. If the determination result is YES, change the write track address to the alternative destination track address (TA) and try again.

If the judgment result is NO, execute data writing to the track, update the number of writes (CNT), and write it to the track, area A2. If CNT does not reach the above-mentioned limit value, Processing ends immediately. When CNT reaches the limit value, track 0. Read sector O and load alternate track address next time. Next, read all the data on the track and write it to the next alternate track address, then track 0. Update the next alternate track address for sector O and set it to track O,
Write to sector O and end the process.

Here, limit management of the number of writes to area A1 will be described. As mentioned above, the number of writes to area A1 is not counted, so in this method, it is managed using alternative track addresses. When the alternative track address reaches a predefined track address (there is no alternative destination), the entire storage medium is replaced.

Next, data writing will be explained using FIG. 6. Data writing is executed sector by sector, and when writing each sector, first check whether SA1 read from area A2 has been replaced (in the example, hexadecimal code (FF))
16 was set as the unsubstituted code). If it has been replaced, it is determined whether 5A1 (replacement source sector address) matches the sector in question, and if it matches, the sector L
Change the sector to +1, write, and end the process. Also.

If the sector has not been replaced and if the sector does not match the SAI, proceed to the next step and perform a similar check for SA2. If the sector has been replaced and SA2 matches the sector, go to sector i+2.

Otherwise, data is written to the sector and the process ends.

Note that SAI and SA2 are recorded in advance when initializing the magnetic disk device.

Next, an embodiment of the apparatus configuration constituting the present invention will be described with reference to FIG.

The magnetic disk 2 is connected to the magnetic disk control device 1,
Controls reading, writing, etc. The magnetic disk 2 has a second
The information explained in the figure, that is, an area A117 for storing the next track address to be substituted, is stored in the track address O, an area 181 for storing the number of times the track has been written, an area 19 for storing the replacement source sector address,
20 and an area A 221 for storing alternative destination track addresses are provided for each track, and information is stored in each area.

The magnetic disk control device 1 has a sequencer 3 that controls the sequence for accessing data on the magnetic disk and controls the interface with a host device, and controls track addresses and sectors of the magnetic disk as described below. - Also controls the sequence of address determination.

Also, within the magnetic disk control device, storage units 4, 5, 22 . . . store track addresses. A storage unit 6 that stores the number of writes, a storage unit 9 that stores 7 sector addresses,
10, 11, 12, 13 also have a comparison section 8.14.15 and a selection section 16.

These functions will be explained below using data writing as an example.

When writing, the sequencer 3 first writes the magnetic disk 2.
control to read area A2 of the track concerned,
Alternative track address set from area 21 of magnetic disk 2 to storage unit 4.

The number of times the track is written in area 18 is set in the storage unit 6, and the replacement source sector address of areas 18 and 19 is set in the storage unit 9 and storage unit 10.

Next, the comparison unit 8 compares the number of times the track has been written in the storage unit 7 and a limit value preset in the storage unit 7,
If there is a match, the alternative destination track address in the storage section 4 is transferred to the storage section 5, the track is set as the corresponding track, and the process returns to the process of reading out the area A2 again. If the track address does not match the limit value, the track address in the storage section 5 is sent to the magnetic disk 2.

Next, the replacement source sector addresses stored in the storage units 9 and 10 are compared with the corresponding sector address set in the storage unit 11 in the comparison units 14 and 15, and if they do not match, the replacement source sector address in the storage unit 11 is compared. The address is selected by the selection unit 16 and sent to the magnetic disk 2. Further, if any of the comparison results match, the corresponding alternative sector address of one of the storage units 12 and 13 is sent to the magnetic disk 2 and data is written. Thereafter, the sector addresses are updated one after another and data is written.

When data writing is completed, the number of writes in the storage unit 6 is updated, the sector address is set to area A2, and area A218 of the corresponding track on the magnetic disk 2 is rewritten.

Next, if the updated number of writes in the storage unit 6 and the limit value in the storage unit 7 do not match, the process ends. If the limit values match, the track replacement process is entered and the contents of the storage section 5 are transferred to the storage section 22, and the contents of the storage section 6 are transferred to the track 0.
, the contents of the storage unit 11 are designated as sector 0, and processing for reading area A117 of the magnetic disk 2 is performed. Load the alternate destination track address into the storage unit 4, and then
The contents of the storage section 22 are returned to the storage section 5, and all data of the track is read. Next, the contents of the storage section 4 are transferred to the storage section 5, and the previously read data is written into the alternative area. When the writing is completed, the next alternative track address in the storage unit 4 is updated, the contents of the storage unit 6 and the storage unit 11 are set to 0 again, and the updated next alternative track address is written to the area A117 of the magnetic disk 2. finish.

Although omitted in the above explanation for ease of understanding, data reading,
Processing of alternative sectors during writing is also performed as described above.

By adopting the magnetic disk control method described above, data can be transferred to a new area before the medium's lifespan is reached.

〔Effect of the invention〕

According to the present invention, even if a medium with a writing lifespan is used to achieve high density, the recorded contents can be transferred to another area before the end of its lifespan, resulting in the loss of information, which is a major drawback. This can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the device configuration of the present invention, Fig. 2 is an explanatory diagram of an embodiment of the arrangement of control information areas on a recording medium, and Figs. 3 and 4 are the areas of Fig. 2. FIGS. 5 and 6 are explanatory diagrams of the information recorded in the memory, and FIGS. 5 and 6 are explanatory diagrams of write control. 1...Magnetic disk control device, 2...Magnetic disk. 3. Sequencer. Figure 1 Figure 2 Figure 3 A1 Ding A No. ヰ Z AZ CN Ding SAI SA2 Ding A No. 5
Figure 6 Figure 1 Segment - Evening Writing Exchange I

Claims (1)

[Claims] 1. A sector is provided for each track of the magnetic disk to record information on the number of times of writing, and when the number of times of writing reaches a predetermined number, the recorded contents of the track are transferred to a track predefined as a reserve. Magnetic disk control method.