JP3480282B2 - Duplicated file I / O device and method and information processing device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a duplicated file I /
The present invention relates to an O device, a method thereof, and an information processing device using the same.

[0002]

2. Description of the Related Art Conventionally, in a dual file I / O device of this type, write processing is performed on both primary and secondary files, and read processing is performed only on the primary file. It is a system adopted to improve.

Japanese Unexamined Patent Publication No. 56-129964 discloses a dual file system in which two files, a primary file and a secondary file, are written in order to improve the efficiency of the data writing process. There is described a technique of sharing a direct memory access channel with a buffer register.

[0004]

The first problem with this prior art is that when a file is read, it is generally always read from the primary file, so if the I / O load on the device containing the primary file is high, That is, the processing efficiency is reduced. The reason is that the I
This is because the / O load is not considered.

The second problem is that the processing time of the program is extended when writing a file. The reason is that the execution of the program is stopped until the writing of both the primary and secondary files is completed.

An object of the present invention is to provide a duplicated file I / O device, a method thereof, and an information processing device which provide fault tolerance due to duplication of files while suppressing deterioration of processing efficiency of user programs.

[0007]

A duplicate file of the present invention
The I / O device is a dual file consisting of a primary file and a secondary file.
Device file and the device information that indicates the device containing the original file.
Information, device information indicating the device where the sub file is,
Position information indicating the position of the written block and finally
Write to either the primary file or the secondary file.
The file that stores the file information that indicates whether the
Load status table and load information indicating the I / O load of the device.
I / O load table to be stored and when I / O request is lead
In case of the above, refer to the position information of the file status table,
The I / O request is a request to the block indicated by the position information.
If there is, the file information in the file status table
Referring to the regular file indicated by the file information, or
Issuing a read to the sub-file and the I / O request
When the request is not for the block indicated by the position information,
The load information and the file form of the I / O load table
Information of the primary file device and the secondary file device information of the state table
Refer to the report to find the correct file in the device with low I / O load.
Or a read to the sub-file and issue the I / O
If the request is a light, then the I / O load table
Load information and the normal file device of the file status table
I / O load by referring to the device information and the secondary file device information
Primary file or secondary file in a device with low
After issuing a write to the other
Issues a write to the main file, and I
/ O of the primary file or the secondary file
Store information in the file information in the file status table
And write the position of the written block to the file status.
Means for storing the position information in the table
And

The duplex file I / O method of the present invention is
The computer receives the I / O request, and the I / O request is returned.
If the file is a
Device information indicating the device where the file is
Device information indicating the device where one of the secondary files is, the last
Position information indicating the position of the block written to and the end
To either the primary file or the secondary file
File information indicating whether the file was completed first.
The I / O request is made by referring to the position information in the file status table.
Is a request to the block indicated by the position information,
Referring to the file information of the file status table,
The primary file or the secondary file indicated by the file information
A read request to the I / O request and the location information
If it is not a request to the indicated block, then the I
Of the I / O load table that stores load information indicating the I / O load
Load information and the normal file device of the file status table
I / O load by referring to the device information and the secondary file device information
Primary file or secondary file in a device with low
A read request to the I / O request and the I / O request is a write
Includes the load information and the file in the I / O load table.
File information of the file status table and the secondary file
Refer to the device information and refer to the above
After issuing a write to the file or the sub-file,
Write to the other sub-file or the main file.
Is issued and the I / O is completed first.
File or information of the sub-file and the file status
The block information written and stored in the file information in the table is written.
The position of the cursor is stored in the position information of the file status table.
It is characterized by including a step.

[0009]

[0010]

[0011]

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, which illustrates an embodiment of the present invention in blocks, the duplicated file I / I of this embodiment is shown.
The O device comprises an I / O destination selecting means 1 and a file status table 2
, I / O load table 3, I / O means 4, and duplicated file 5.

The file status table 2 shows the device in which the primary and secondary files of the duplicated file 5 are located, the position of the last written block, and whether the last write to the primary or the secondary is completed first. Remember.

The I / O load table 3 stores information about the I / O load of each disk device configured in the computer system, for example, the I / O busy rate. This information is updated at any time by the I / O means 4 and the components of the OS that process general disk I / O.

In response to a read request from the user program 6, the I / O destination selection means 1 checks whether the position of the block to be read is the same as the position stored in the file status table 2. If they are the same, the file written on the previous side is selected as the first file. If the position of the read block is different from the position stored in the file status table 2, the I / O destination selection unit 1 looks at the I / O load table 3 and
Select a file on the device with the lightest load. In response to a write request from the user program 6, the I / O destination selection means 1 first confirms that the previous write has been completed, then looks at the I / O load table 3 to see which device has the lower load. Select the file in the as the first file and the remaining side as the second file.

If a read request is made, the I / O means 4 issues a read to the first file selected as described above, and waits for completion. In the case of a write request, the first and second
A write is issued to the file, wait until the write of either file is completed, and re-register the necessary information in the file status table 2.

Next, the operation of this embodiment will be described with reference to FIG. 2 showing the flow of operation of this embodiment in addition to FIG.

User program 6 to duplicated file 5
When the I / O is requested, the I / O destination selection means 1 determines the type of the requested I / O (step A1), and in the case of read, the position of the read block is the file status table 2
If it is different from the previously written position stored in, by referring to the I / O load table 3, the primary or secondary file in the device with the lower load is used as the first file and the other as the second file. Select (steps A2, A5
A7). In the case of read, the second file is not used even if selected. If the position of the block to be read is the same as the position of the previous write, the primary or secondary file for which the previous write is completed first is selected as the first file from the file status table 2 (steps A2, A3). I /
If the type of O is write, the I / O destination selection means 1 first waits until the previous write is completed (step A4), and then, according to the load from the I / O load table 3 as described above. Select the first and second files (step A
5-A7).

The I / O means 4 issues a read or write to the first file in response to the request (step A8). In the case of write, it is also issued to the second file (steps A9 and A10). Then I /
Wait for one O to complete (step A11). In the case of writing, the file for which I / O is completed first is stored in the file status table 2 together with the written position (steps A12 and A13). Normally, the I / O load is low,
The write on the side selected as the first file should complete first.

Next, with reference to FIGS. 3 to 5 together with FIGS. 1 and 2, the operation of this embodiment will be described using a specific example.

As shown in FIG. 3, for example, the file status table 2 stores the device with the primary file, the device with the secondary file, the last written position, and the file for which the last writing was completed first. There is. Further, as shown in FIG. 4, the I / O load table 3 stores the load of the device at that time.

The user program 6 determines that the position P2 (P2 ≠ P
1), the I / O destination selection means 1 knows from the file status table 2 (FIG. 3) that the position is different from the last written position (step A1,
A2). Next, from the I / O load table 3 (FIG. 4), it is known that the load of the device D2 is low between the device D1 and the device D2, and the sub file is selected as the first file and the primary file is selected as the second file. (Steps A5 and A7). I /
The O means 4 therefore reads from the sub file and waits for its completion (steps A8, A9, A11).

When the user program 6 tries to write the position P3, the I / O destination selecting means 1 first waits for the last write completion (step A4), and the I / O load table 3
From FIG. 4, the secondary file is selected as the first file and the primary file is selected as the second file (step A).
5, A7).

The I / O means 4 first issues a write to the secondary file and then a write to the primary file (steps A8 to A11). If the writing of the sub file is completed first, the contents of the file status table 2 are as shown in FIG.

[0026]

As described above, the effects of the present invention are
It is possible to utilize the fault tolerance by duplication of files while suppressing the deterioration of the processing efficiency of the user program.

The reason is that the read / write is issued with priority to the file in the device having a low I / O load.
I / O of either primary or secondary file for write
This is because the user program can be executed when is completed.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing an example of an operation in this embodiment.

FIG. 3 is a diagram showing a specific example of a file status table of this embodiment.

FIG. 4 is a diagram showing a specific example of an I / O load table according to this embodiment.

FIG. 5 is a diagram showing a specific example of a state changed from FIG. 3 in the file state table of this embodiment.

[Explanation of symbols]

1 I / O destination selection means 2 File status table 3 I / O load table 4 I / O means 5 Duplicated file 6 user program

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Claims (2)

(57) [Claims] 1. Duplex consisting of a primary file and a secondary file
File and The device information indicating the device in which the primary file is stored, the sub file
Device information indicating which device has the file, the last written block
Position information indicating the position of the lock and finally the normal file
Or which of the above sub-files has been written first
A file status table that stores file information indicating whether I / O storing load information indicating I / O load of the device
Load table, If the I / O request is a read, the file status table
Of the location information of the location information
If the request is for a block indicated by
Referring to the file information in the status table, the file information
Read to the primary file or the secondary file indicated by
A block issued by the I / O request and indicated by the position information
Is not a request to the I / O load table,
The regular file device of the load information and the file status table
Information and the secondary file device information, the I / O load
To the primary or secondary file on the lower device
When a read is issued and the I / O request is a write
Indicates the load information and the file in the I / O load table.
Information of the primary file device and the secondary file device in the status table.
By referring to the device information, the main unit in the device with a low I / O load
After issuing a write to the file or the sub-file,
Write to the sub file or the main file on the other side
Is issued and the I / O is completed first.
File or the information of the sub file and the file status table
The block that is stored and written in the file information of
Position of the file is stored in the position information of the file status table.
Means for duplicating file I / O
apparatus. 2. The computer receives an I / O request,
If the I / O request is read, the duplicated file
Device information indicating the device on which one of the primary files is located, duplicate
The device with the subfile that is the other side of the encrypted file
Device information, a position indicating the position of the last written block
Location information and finally the primary file or the secondary file
File that indicates which write to which file was completed first
Refer to the location information in the file status table that stores information
However, the I / O request is sent to the block indicated by the position information.
If it is a request, the file in the file status table
Emotion Information, and the normal file indicated by the file information
Alternatively, a read is issued to the sub file and the I / O is required.
When the request is not a request to the block indicated by the position information
Stores load information indicating the I / O load of the device.
The load information of the I / O load table and the file status table
Of the primary file device information and the secondary file device information of
Please refer to the above-mentioned main file in the device with low I / O load.
Or issue a read to the sub-file to request the I / O
Is a light, the load in the I / O load table
Information and the normal file device information of the file status table
I / O load is low by referring to the report and the above-mentioned secondary file device information.
To the primary file or the secondary file on the local device.
After issuing the second
A write is issued to the correction file and I / O is performed first.
Information of the primary file or the secondary file that has been completed
Is stored in the file information of the file status table,
The position of the selected block before the file status table
Characterized by including a step of storing in the position information
Duplicated file I / O method.