JP2746102B2 - One point backup method of business data file in case of magnetic disk device failure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-point backup of a business data file in the event of a magnetic disk device failure in a computer system having a magnetic disk device for storing business data files. .

[0002]

2. Description of the Related Art Generally, in a computer system having a magnetic disk device for storing business data files,
A process for coping with a failure of the magnetic disk device is performed as follows.

The business data stored in the business data file on that day is saved in an auxiliary storage device such as a magnetic tape after the business processing on that day is completed.

When a failure occurs in a magnetic disk drive,
The business data is restored from the auxiliary storage device to the business data file in the magnetic disk device using the auxiliary storage device. As a result, recovery of business data having contents up to the day before the failure date is realized.

[0005] The business data updated from the time of the save to the time of the occurrence of the failure (the business data updated by the time of the failure on the date of the failure) is recovered by some method (method such as re-input of the business data). Is done.

In such a "method for coping with a failure of a magnetic disk device", when a failure occurs in a magnetic disk device during business processing, only the business data up to the previous day is saved in the auxiliary storage device. However, there is a problem that the business data updated from the start of the business on the day (failure occurrence date) to the occurrence of the failure may be wrong.

Also, since the recovery (recovery) processing is composed of the above-mentioned two steps, the time required for recovery (business interruption time) when a failure occurs in the magnetic disk device is long. There was also a problem that there was a possibility.

As a method for solving the above problems, there is a method based on duplexing of a magnetic disk device for storing business data files.
Japanese Patent Application Publication No. -14122 introduces a "business data file backup method for a failure of a magnetic disk device".

In this "business data file backup system for failure of magnetic disk device", two magnetic disk devices (a pair of magnetic disk devices) are provided with the same business data file, and the replacement magnetic disk device is further provided. Is prepared.

In this method, the double writing means executes the double writing of the business data to the pair of magnetic disk devices, and the control information creating means writes the business data file in the event of a failure. The recovery control information is created, and the recovery instruction means instructs the recovery of the business data file in the event of a failure (see page 1, lines 7 to 12 in the publication).

That is, in the "backup method for business data files in the event of a failure of a magnetic disk device", the above-mentioned problem is caused by the installation of a pair of magnetic disk devices and a replacement magnetic disk device, and the double writing of business data files. The point has been resolved. As described above, in the method for solving the above-mentioned problems by duplicating the magnetic disk device, it is necessary to install a magnetic disk device for realizing the duplication and to double write the business data file.

[0012]

In the "method for coping with a failure of a magnetic disk device by duplicating a magnetic disk device" such as the "backup method of business data files for a failure of a magnetic disk device" described above, duplication is realized. Therefore, there is a problem that the required capacity of the magnetic disk device becomes excessive and the efficiency of the business process is deteriorated. there were.

On the other hand, such a "method for coping with a failure of the magnetic disk device by duplicating the magnetic disk device".
If no is adopted, as described above, the following problems have occurred.

There is a possibility that business data updated from the start of the business on the day of the failure to the time of the failure may cause a failure.

There is a possibility that the time required for recovery when a failure occurs in the magnetic disk device (business interruption time) may take a long time.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a magnetic disk drive capable of solving the above-mentioned problems without increasing the capacity of a magnetic disk drive and deteriorating the efficiency of business processing. An object of the present invention is to provide a one-point backup method for business data files when a disk device fails. In other words, the business data file one-point backup method at the time of magnetic disk device failure of the present invention is used when an access error to a business data file in the magnetic disk device repeatedly occurs (this situation is described in the present specification). In the book, "I / O
(Input / Output) error.)
Based on the detection of the I / O error, it is recognized that there is a high possibility that a failure of the magnetic disk device (a failure of the location where the business data file is stored in the magnetic disk device) is high. The above-described object is achieved by backing up the business data file to another location.

[0017]

According to the present invention, there is provided a one-point backup system for business data files in the event of a failure of a magnetic disk device. In a computer system having a magnetic disk device for storing business data files, the file name of each business data file A backup information table that stores the file name of the backup business data file corresponding to each business data file and the correspondence information between the backup business data file and the name of the auxiliary storage device where the backup business data file exists, and the file name of each business data file A catalog file that stores information corresponding to the device name of the magnetic disk device in which each business data file exists and the backup instruction flag, and an access error when the business data file is accessed by the application program. I / O error sensing means for sensing the occurrence of an I / O error when it repeatedly occurs over a specified number of times, and a business data file relating to the I / O error detected by the I / O error sensing means A copy unit that generates a backup business data file to be copied and copies the business data in the business data file to the backup business data file; and the backup information table and the catalog file reflecting the copy by the copy unit. And a catalog converter for updating the data.

In the computer system having a magnetic disk device for storing business data files, the file name of each business data file and the business data file A backup information table that stores information on the correspondence between the backup business data file name corresponding to the backup business data file and the device name of the auxiliary storage device in which the backup business data file exists, the file name of each business data file and the respective business A catalog file that stores information on the correspondence between the device name of the magnetic disk device where the data file exists, the backup instructing flag, and the backup necessity flag, and when the application program accesses the business data file I / O error sensing means for sensing the occurrence of an I / O error when the access error repeatedly occurs more than a prescribed number of times, and business data relating to the I / O error sensed by the I / O error sensing means Determine whether the backup of the file is necessary by referring to the backup necessity flag in the catalog file,
Copy means for generating a backup business data file corresponding to the business data file when it is determined that "backup is required", and copying business data in the business data file to the backup business data file, A catalog converter for updating the backup information table and the catalog file by reflecting the copy by the copying means.

[0019]

The business data file one-point backup method in the event of a magnetic disk device failure according to the present invention is applied to a computer system having a magnetic disk device for storing business data files, and performs the following operations. That is, the backup information table stores the correspondence between the file name of each business data file, the file name of the backup business data file corresponding to each business data file, and the device name of the auxiliary storage device in which the backup business data file exists. Store the information.
The catalog file stores information on the correspondence between the file name of each business data file, the device name of the magnetic disk device in which each business data file exists, and the backup instruction flag. The I / O error sensing means senses the occurrence of an I / O error when an access error repeatedly occurs more than a specified number of times when an application program accesses a business data file. The copy unit is configured to output the I / O detected by the I / O error detection unit.
A backup business data file corresponding to the business data file relating to the error is generated, and the business data in the business data file is copied to the backup business data file. The catalog converter updates the backup information table and the catalog file by reflecting the copy by the copy unit.

The operation data file one-point backup system in the event of a magnetic disk drive failure according to the present invention can also perform the following operations. That is, the backup information table stores the correspondence between the file name of each business data file, the file name of the backup business data file corresponding to each business data file, and the device name of the auxiliary storage device in which the backup business data file exists. Store the information. The catalog file stores information on the correspondence between the file name of each business data file, the device name of the magnetic disk device in which each business data file exists, a backup instruction flag, and a backup necessity flag. The I / O error sensing means senses the occurrence of an I / O error when an access error repeatedly occurs more than a specified number of times when an application program accesses a business data file. The copying means determines whether or not a backup of the business data file relating to the I / O error detected by the I / O error detecting means is necessary by referring to the backup necessity flag in the catalog file. Is necessary, a backup business data file corresponding to the business data file is generated, and the business data in the business data file is copied to the backup business data file. The catalog converter updates the backup information table and the catalog file by reflecting the copy by the copy unit.

[0021]

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a business data file one-point backup system in the event of a magnetic disk drive failure according to a first embodiment of the present invention.

The one-point backup method for business data files in the event of a failure in the magnetic disk device of the present embodiment comprises an application program 1 and an I / O error sensing means 20
, A copy unit 3, a catalog converter 4, a backup information table 5, a catalog file 6, a magnetic disk device 7, and a magnetic disk device 8. In the present embodiment, the access unit 2 is an operating system (OS).
m) copy means 3, catalog converter 4
And the backup information table 5 stores the RAS (Reli
availability, Availability, Serv
Iceability) system.

The magnetic disk device 7 stores a business data file 70. Also, the magnetic disk drive 8
, A backup business data file 80 corresponding to the business data file 70 is generated. In FIG. 1, the business data file 70 and the backup business data file 80 are provided on different magnetic disk devices (the magnetic disk device 7 and the magnetic disk device 8), but both are stored on the same magnetic disk device. It is also possible to provide a file. The auxiliary storage device in which the backup business data file 80 is generated is not limited to a magnetic disk device, but is an auxiliary storage device similar in recording method (access method) to a magnetic disk device such as an optical disk device. Is also good.

Referring to FIG. 2, the processing of the business data file one-point backup method in the event of a magnetic disk device failure according to the present embodiment includes an access error occurrence determination step 2
1, a specified number excess determination step 22, an access retry step 23, an I / O error detection and notification step 24, a backup business data file generation step 25, a business data copy step 26, and a catalog file update step 27 and a backup information table updating step 28.

FIG. 3 is a diagram showing an example of the configuration of the backup information table 5. The backup information table 5 includes an old file name indicating a file name (file identification information) of a business data file being backed up (for example, the business data file 70 in FIG. 1), and a backup business corresponding to the business data file. A new file name indicating the file name of the data file (for example, the backup business data file 80 in FIG. 1), and the device name of the magnetic disk device (generally, an auxiliary storage device) in which the backup business data file exists. (Device identification information).

FIG. 4 is a diagram showing an example of the configuration of the catalog file 6. The catalog file 6 includes, for each business data file, the file name of the business data file, the device name of the magnetic disk device in which the business data file exists, and whether the business data file is currently backed up (the business data file is And a backup instructing flag indicating whether or not a backup business data file corresponding to the file has been generated (referred to when the backup means 3 generates the backup business data file). The disk type of the magnetic disk device and the like can also exist as other information.)

Next, the operation of the business data file one-point backup method in the event of a failure of the magnetic disk device of the present embodiment configured as described above will be described.

When the application program 1 accesses the business data file 70 in the course of executing business processing in the computer system to which this embodiment is applied, the access is realized via the access means 2 in the OS. . At this time, the access unit 2 refers to the catalog file 6 and recognizes the magnetic disk device 7 in which the business data file 70 to be accessed exists.
The business data file 70 in the magnetic disk device 7
Is the VTOC (Vol.) In the magnetic disk device 7.
It is recognized based on the information of the “Table Table of Contents”.

The I / O error sensing means 20 in the access means 2 checks (determines) whether or not an access error has occurred to the business data file 70 in the magnetic disk device 7 at the time of the access (step 2).
1).

The I / O error sensing means 20 performs step 2
When the occurrence of an access error is detected in step 1, it is determined whether the number of occurrences of the access error in the access exceeds a specified number (step 22). In addition,
If the occurrence of an access error is not detected in step 21, the process of the business data file one-point backup method at the time of the access in the magnetic disk device failure of this embodiment ends.

If the I / O error sensing means 20 determines in step 22
If it is determined that "the number of occurrences of the access error does not exceed the specified number", the access means 2 retry (retry) the access (step 23).

The I / O error detecting means 20 performs step 2
If it is determined in step 2 that "the number of occurrences of the access error exceeds the prescribed number", the occurrence of an I / O error (the occurrence of the prescribed number of access errors) relating to the business data file 70 is detected, and the RAS is detected. This is notified to the copying means 3 in the system (step 24).

The "specified number of times" in the determination in step 22 is the number of times determined from an empirical viewpoint or the like.
Number of times determined based on viewpoints such as "access error is still a mild symptom and access is retried as much as possible while the occurrence of the access error is still unlikely to cause a failure of the magnetic disk device" It is. That is, for the purpose of executing the backup process before the business data file cannot be read due to the failure of the magnetic disk device, and avoiding the useless backup process as much as possible, Is determined.

The copy means 3 receives the notification in step 24, and receives the backup business data file 80.
A backup business data file corresponding to the business data file 70 is generated in the magnetic disk device 8 (step 25).

Further, the copying means 3 copies the business data in the business data file 70 to the backup business data file 80 (step 26).

Thus, the business data in the business data file 70 can be saved (backed up) in the backup business data file 80 in the latest state before a failure occurs in the magnetic disk device 7.

The catalog converter 4 has a function of enabling the application program 1 to access the business data copied to the backup business data file 80 by the copying means 3 without being aware that the copy has been made.

That is, the catalog converter 4 sets information indicating "backing up" in the backup instructing flag for the business data file 70 in the catalog file 6 (step 27).

Further, the catalog converter 4 has a RAS
In one entry (record) in the backup information table 5 in the system, the file name of the business data file 70 is set in the “old file name”, and the file name of the backup business data file 80 is set in the “new file name”. Then, the device name of the magnetic disk device 8 is set in the "backup device name" (step 28).

By the processing in steps 27 and 28, the update of the catalog file 6 and the backup information table 5 in which the copy processing by the copy means 3 is reflected is realized.

The above operation realizes a temporary (one-point) backup process based on the occurrence of an I / O error when accessing the business data file 70.

Thereafter, the application program 1
When the user accesses the business data file 70, both the catalog file 6 and the backup information table 5 are referenced to access the backup business data file 80 (the application program 1 accesses the business data file 70). I am conscious of it.) That is, based on the fact that “in backup” is set in the backup instructing flag for the business data file 70 in the catalog file 6, the corresponding entry (the file name of the business data file 70 The “backup device name” and “new file name” in the entry of “file name” are referred to, and the backup business data file 80 in the magnetic disk device 8 is accessed.

When the business process on the current day (I / O error occurrence date) is completed, a recovery process of the business data file 70 is executed (this recovery process is realized by the conventional technology). Business data file 7
0 is accessed. Here, at the time of recovery processing, the business data file 70 in the catalog file 6
The information of “during backup” in the backup-in-progress instruction flag is released, and the entry of the business data file 70 in the backup information table 5 is deleted.

Next, a description will be given of a business data file one-point backup method in the event of a magnetic disk device failure according to a second embodiment of the present invention. The configuration of the business data file one-point backup method at the time of magnetic disk drive failure of the present embodiment is also shown in the block diagram of FIG. However, the configuration of the catalog file 6 is as shown in FIG. That is, this catalog file 6
Is, for each business data file, the file name of the business data file, the device name of the magnetic disk device where the business data file exists, and whether the business data file is backed up at the moment (corresponding to the business data file). A backup instruction flag that indicates whether a backup business data file has been generated) and information that indicates whether a one-point backup process is necessary in view of the importance of the business data file (backup required). (A flag indicating whether or not the disk type of the magnetic disk device is referred to when the backup means 3 generates the backup business data file).

Next, the operation of the business data file one-point backup system in the event of a failure of the magnetic disk device of the present embodiment configured as described above will be described.

The operation of the outline is the same as the operation in the first embodiment, and therefore only the operation different from the operation in the first embodiment will be described.

Upon receiving the notification of the occurrence of the I / O error (see step 24 in FIG. 2), the copying means 3 determines whether the business data file 70 according to the notification needs to be backed up in the catalog file. 6 is determined based on the backup necessity flag relating to the business data file 70 in FIG.

The copying means 3 generates the backup business data file 80 in the magnetic disk device 8 only when it is determined that a backup is necessary in this determination (see step 25).

This eliminates the need for one-point backup processing, which is less necessary, and brings about an improvement in the overall processing efficiency of business processing.

[0051]

As described above, according to the present invention, based on the detection of an I / O error with respect to a business data file in a magnetic disk drive, the business data file can be stored in another magnetic disk drive before an actual failure occurs. By backing up at a location, the following effects can be achieved without increasing the required capacity of the magnetic disk device and without deteriorating the efficiency of business processing.

The possibility that the phenomenon that “the business data updated from the start of the business on the day of the failure to the time of the failure becomes invalid” is reduced.

The business interruption time for recovery from the failure of the magnetic disk device is reduced.

By providing a backup necessity flag in the information in the catalog file, it is possible to realize a one-point backup process only for business data files that really need to be backed up in view of the importance and the like. Thus, there is an effect that the overall processing efficiency of business processing can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a business data file one-point backup method at the time of a magnetic disk device failure according to a first embodiment and a second embodiment of the present invention.

FIG. 2 is a flowchart showing a process of a first embodiment of a business data file one-point backup method at the time of magnetic disk device failure;

FIG. 3 is a diagram illustrating an example of a configuration of a backup information table in FIG. 1;

FIG. 4 is a diagram showing an example of a configuration of a catalog file in a first embodiment of a one-point backup method of a business data file when a magnetic disk device fails.

FIG. 5 is a diagram showing an example of a configuration of a catalog file in a second embodiment of a one-point backup method of a business data file when a magnetic disk device fails.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 application program 2 access means 3 copy means 4 catalog converter 5 backup information table 6 catalog file 7, 8 magnetic disk drive 20 I / O error sensing means 70 business data file 80 backup business data file

Claims (3)

(57) [Claims] In a computer system having a magnetic disk device for storing business data files, a file name of each business data file, a file name of a backup business data file corresponding to each business data file, and the backup business data A backup information table that stores information corresponding to the device name of the auxiliary storage device where the file exists, the file name of each business data file, the device name of the magnetic disk device where each business data file exists, and a backup instruction flag; And an I / O error that is detected when an access error repeatedly occurs more than a specified number of times when an application program accesses a business data file.
/ O error detecting means, and a backup business data file corresponding to the business data file relating to the I / O error detected by the I / O error detecting means, and the business data in the business data file is backed up. And a catalog converter for updating the backup information table and the catalog file by reflecting the copy by the copy unit. File one point backup method. 2. A computer system having a magnetic disk device for storing business data files, a file name of each business data file, a file name of a backup business data file corresponding to each business data file, and the backup business data. A backup information table that stores information corresponding to the names of the auxiliary storage devices in which the files exist; a file name of each business data file; a device name of a magnetic disk device in which each business data file exists; A catalog file that stores information corresponding to a backup necessity flag and an I / O error that is detected when an access error repeatedly occurs over a specified number of times when an application program accesses a business data file. I
I / O error detecting means and whether or not backup of the business data file relating to the I / O error detected by the I / O error detecting means is necessary is referred to by referring to the backup necessity flag in the catalog file. When the judgment is made and "backup is required", a backup business data file corresponding to the business data file is generated, and the business data in the business data file is copied to the backup business data file. And a catalog converter for updating the backup information table and the catalog file by reflecting the copy made by the copying means. 3. The one-point backup method for a business data file in the event of a failure of a magnetic disk device according to claim 1, wherein the auxiliary storage device in which the business data file for backup is generated is a magnetic disk device.