JPH0448452A - High speed access interface device for magneto-optical disk - Google Patents

Abstract

PURPOSE:To reduce the number of times of I/O to a magneto optical disk by making the controller of the magneto optical disk device have the buffer memory of several track portions, buffering writing data on a same track to some extent and writing on the magneto optical disk only when the buffer memory is saturated. CONSTITUTION:When a host computer 1 has writing requirement to a disk, it does not execute writing actually immediately but stores data to be written in a buffer memory once. After that, when it has the writing requirement to the block of the same track as the block to exist in the buffer memory 3, the data of the block re put in the buffer memory of the track, when the buffer memory 3 is saturated, the data is written in a magneto optical disk in the buffer memory 3 according to normal algorism and the data to have the new writing requirement are written in the buffer memory 3 instead of them. Thus, the number of times of I/O is reduced and the increasing operating speed of t magneto optical disk is attained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an input/output control device for a magneto-optical disk.

BACKGROUND OF THE INVENTION In recent years, optical disks started out as write-once types that can be written only once, and rewritable magneto-optical disks that can be rewritten any number of times have been developed and have become popular as they can be connected to general computer systems. It is especially used in electronic filing systems that require large-capacity data storage. However, access times are slower than hard disks, so faster speeds are desired.

Due to the characteristics of the material of the media, when writing data to a certain sector of a magneto-optical disk, the data in that sector must be cleared to zero several times, and then the data must be written again. Additionally, it is necessary to verify the sector to check whether the written data is correct. Therefore, the disk must rotate three times for - times of write operations, which is one of the reasons why access to magneto-optical disks is slower than that of hard disks.

In general, disk read/write operations are performed in blocks with several consecutive sectors as a unit of allocation. Therefore, even if there are write requests to several blocks, and the blocks are on the same track, I10 requests to the physical disk are issued as many times as there are blocks. Furthermore, in the case of magneto-optical dinulling, for the reasons mentioned above, the average number of rotations per machining/○ request is 2.6.

Problems to be Solved by the Invention For example, if there is a request to write n blocks on the same track to a magneto-optical disk, (2,6*n) rotations are required to write all of these blocks to the disk. Also, on the system side, the n number of operations/○ processing becomes an overhead.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention aims to speed up disk access by completing writing of a plurality of blocks on the same track with -1 write request.

Means for Solving the Problems In order to achieve the above object, the present invention provides a controller for a magneto-optical disk device with backup memory for several tracks, and buffers write data on the same track to some extent. , when the buffer memory is saturated, one I/O is executed at a certain time according to a predetermined algorithm.
This is an attempt to increase the speed of the magneto-optical disk by configuring it so that one track's worth of data is written by ○ and by reducing the number of physical operations/○.

Effect of the Invention According to the above configuration, when there is a write request to the disk, the present invention does not actually perform the write process immediately, but stores the data to be written in the buffer memory once, and then writes the data to the blocks existing in the buffer memory. When there is a write request to a block on the same track, the data of that block is placed in the corresponding memory, and when the backup memory is saturated, the data in the buffer memory is written to the magneto-optical disk according to the predetermined algorithm. Instead, the newly requested data is written into the buffer memory, and the speed of the magneto-optical disk is increased by reducing the number of physical I10 operations.

Embodiment Hereinafter, the structure and operation of a high-speed access interface device for a magneto-optical disk according to an embodiment of the present invention will be explained based on the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a flowchart of its operation.

When a command is received from the host computer 1 to the magneto-optical disk drive 4 (step 1, hereinafter abbreviated as S1), the control device 2 determines whether it is a read request or a write request (S2), and a write request. If it is a request, the control device 2 accepts the block-by-block write request, scans the buffer memory 3 based on the address of the track where the block to be written exists, and checks whether data in that track exists ( S11). If the data exists, the data is additionally stored at the block address position in the buffer memory (S16).

However, the buffer memory is finite. For example, if there is only memory for m tracks, if a new write request does not match any of the tracks stored in the buffer memory (S11), the free backup memory is 512), and if so, read that data from the request trunk to buffer memory 3 (S1
5), the requested block data is transferred to the buffer memory 3 (S1e), but if there is no free buffer memory, data for a certain track on the buffer memory 3 is selected according to the following criteria (S13), and 1 is transferred to the media. Tracks are written (S14). After that, all data on the requested trunk is read from the magneto-optical disk into the buffer memory 3 (S15). Data of a new track is stored in the empty buffer memory (S1
e).

Which track's data in the buffer memory will be evicted first is determined by considering the following factors.

1 The number of stored blocks is the largest.

2 The stored data is the oldest.

3. Closest to the current position of the drive head.

According to the above algorithm, when the capacity of the buffer memory is large and the hit rate of the track of the imported data is high, the number of physical accesses to the magneto-optical disk is reduced, thereby improving performance. Furthermore, in response to lead requests,
If the data of the block to be loaded is contained in the buffer memory (S21), the data of the requested block can be transferred from the buffer memory without actually reading it from the disk (S22), leading to faster processing. .

As described in detail, the high-speed access interface device for a magneto-optical disk of the present invention has a controller of a magneto-optical disk device with a buffer memory for several tracks, and buffers write data on the same track to some extent. Since the configuration is such that data is written to the magneto-optical disk only when the buffer memory is saturated, the number of Ilo operations to the magneto-optical disk is reduced, and the operation speed can be increased.

Furthermore, even in conventional file systems where the allocation unit is a fixed block length, buffering is performed on the peripheral device side rather than on the host computer, so speeds can be increased without any particular software improvements.

Therefore, it is possible to improve the performance of magneto-optical disks whose access time is much slower than that of hard disks.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a high-speed access interface device for a magneto-optical disk according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the processing flow of the control device 2 of FIG. 1. 1...Host computer, 2...Control device, 3...Buffer memory, 4...
Magneto-optical disk drive.

Claims (1)

[Claims] An optical system having a plurality of memories that temporarily buffer data to be written to a magneto-optical disk on a track-by-track basis, and a control device that writes data on the memory to the magneto-optical disk according to a predetermined algorithm when the memory is saturated. High-speed access interface device for magnetic disks.