JP3794322B2 - Data copy system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data copy system, and more particularly to a data copy system that performs logical disk mirroring on a computer system as a countermeasure against a failure.
[0002]
[Prior art]
Conventionally, in a storage device built in or connected to a computer, a logical disk is copied within the storage device or between storage devices, and data is transferred using the copied logical disk when a failure occurs in the original logical disk. The storage device function to be restored is used.
[0003]
FIG. 6 is a block diagram for explaining a conventional example of data copy using this storage device function. In the conventional example shown in FIG. 6, the logical disk 1 and the logical disk 2 may be in the same computer or storage device as long as data transfer is possible, or in different devices. Data has already been written in the logical disk 1 and includes an OS management information area 11, a data management information area 12, a data writing area 13, and a data unwritten area 14. Information for managing the logical disk 1 from an operating system such as a computer or an application is registered in the OS management information area 11. In the data management area 12, information indicating the location of data written in the data writing area 13 is registered. The data writing area 13 stores the actually written data, and the data unwritten area 14 is an unused area where no data is written.
[0004]
In this system, copying of the logical disk 1 is performed as a countermeasure against failure at the elapse of a fixed time or at the end of daily operation. In this case, in the conventional system, the entire logical disk 1 is copied to another logical disk 2. That is, in the example shown in FIG. 6, all of the OS management information 11, the data management information 12, the data writing area 13, and the data unwritten area 14 of the logical disk 1 are copied to the logical disk 2. An OS management information area 21, a data management information area 22, a data writing area 23, and a data unwritten area 24 are created.
[0005]
[Problems to be solved by the invention]
However, in the conventional data copy system, the data of the copy source logical disk 1 and the copy destination logical disk 2 are all the same, and therefore OS management information (reference numerals 11 and 11) for managing the storage device from higher-level means such as OS and applications. 21) is the same. This OS management information includes OS volume identification information (for example, a drive number such as a signature for Windows (registered trademark)) for the OS to manage the logical disk. The copy source logical disk 1 and the copy destination logical disk 2 cannot be used individually. Although this does not cause a problem when used only for the purpose of restoration as usual, the normal operation is resumed on the logical disk 1 after the copy is completed, and the copy destination logical disk 2 is used for, for example, a search operation in a database system or the like. It would be convenient if it would be possible to carry out another task.
[0006]
Further, since all of the logical disk 1 is copied to the logical disk 2 regardless of the amount of the unwritten data area 14 in the logical disk 1, there is no data and the unused area that is originally not required to be copied. There is a problem that an operation to copy 14 to the logical disk 2 occurs and an extra time is required until the copy operation is completed.
[0007]
Further, since copying of the data unwritten area 14 which essentially does not require copying is performed, a physical failure occurs in the area where the unwritten area 14 is copied (that is, the data unwritten area 24) in the copy destination logical disk 2. If this exists, there is a problem that the copy process results in an error.
[0008]
SUMMARY OF THE INVENTION In view of the above problems, the present invention has an object to provide a data copy system that shortens processing and prevents unnecessary errors by omitting copying of areas that are not originally required for copying between logical disks. And
[0009]
[Means for Solving the Problems]
In order to achieve this object, the present invention relates to a copy source logical disk in which data has already been written in a data copy system for copying data on a logical disk in an information storage device to another logical disk as a countermeasure against a failure. An OS management information area in which information for managing the logical disk from a higher-level means is recorded, and a copy destination logical disk of data and a copy operation control means The data management information area in which the location of the write data is recorded, the data write area in which the write data from the higher-level means is recorded, and the unused data unwritten area, and the copy operation control means Among the areas of the copy source logical disk, the data unwritten area Characterized in that it does not copied to the destination logical disk. If the system is configured in this way, copying of the data unwritten area where no data exists is not performed in the copy operation of the logical disk, so this processing time can be reduced and the data unwritten area in the copy destination logical disk can be reduced. Even if there is a physical failure in the corresponding area, the area is not accessed, so an error does not occur.
[0010]
The present invention also relates to a copy source logical disk in which data has already been written and a copy destination logical of the data in a data copy system that copies data on a logical disk in an information storage device to another logical disk as a countermeasure against a failure. A disk and a copy operation control means, wherein the copy source logical disk has an OS management information area in which information for managing the logical disk from higher-order means is recorded, and the location of write data in the logical disk A copy management logical area, a data write area in which write data from the higher-level means is recorded, and an unused data unwritten area; and the copy operation control means includes the copy source logical disk Of these areas, the OS management information area is stored in the copy destination logical disk. Characterized in that it does not copy.
When the system is configured in this manner, the OS management information area for managing the logical disk is not copied from the higher-level means in the logical disk copy operation in the logical disk copy operation. The OS management information is not the same, and the copy source and copy destination logical disks can be used from the same computer.
[0011]
In this data copy system, the copy source logical disk and the copy destination logical disk may be in the same device or in different devices connected to each other. For example, to realize the system of the present invention, both the copy source logical disk and the copy destination logical disk may be provided in the same computer or storage device, or the copy source logical disk and the copy destination logical disk are different computers or storages. It can be provided in the apparatus, or the copy source logical disk can be arranged in the computer while the copy destination logical disk can be provided in a storage device connected to the computer.
[0012]
On the other hand, the method according to the present invention is a method of copying logical disk data in a computer or one or more information storage devices connected to the computer to another logical disk for the purpose of troubleshooting. The disk has an OS management information area in which information for managing the logical disk from the higher level means is recorded, a data management information area in which the location of write data in the logical disk is recorded, and a write from the higher level means A data writing area in which data is recorded, and an unused data unwritten area, and the method includes only the data management information area and the data writing area in the storage area of the copy source logical disk. Is copied to a corresponding area of the copy destination logical disk.
[0013]
Furthermore, the present invention relates to a copy source logical disk in a program for copying data on a logical disk in a computer or one or more information storage devices connected to the computer to another logical disk for troubleshooting. Includes an OS management information area in which information for managing the logical disk from the higher-level means is recorded, a data management information area in which the location of write data in the logical disk is recorded, and write data from the higher-level means Is recorded, and an unused data unwritten area is included, and the program extracts only the data management information area and the data writing area from the copy source logical disk area. And transfer it to the corresponding area of the destination logical disk. A program for controlling the computer or storage device.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic block diagram showing the configuration of the data copy system according to the first embodiment of the present invention. Referring to FIG. 1, one information storage device 33 is connected to a computer 31 via a data transmission / reception bus 32. The information storage device 33 is, for example, an external hard disk device, a magnetic disk device, a magnetic tape device, an optical disk device such as a CD or a DVD, and has a plurality of logical disks 1 to n under its control. Each logical disk in the apparatus is connected by an internal signal line 35 via a control unit 34. The control unit 34 records and reproduces data on, for example, the logical disk 1 in response to a data read / write command from the computer 31 during normal operation, but reads data from the logical disk 1 during another data copy operation. Copy to 2 is performed. The control unit 34 is operated by a program 36 stored in a built-in storage medium.
[0015]
FIG. 2 is a schematic block diagram for explaining the configuration of the logical disk 1 and the data copy operation. As shown in FIG. 2, data has already been written in the logical disk 1 and includes an OS management information area 11, a data management information area 12, a data writing area 13, and a data unwritten area 14. . Information for managing the logical disk 1 from the operating system or application of the computer 31 is registered in the OS management information area 11. In the data management area 12, information indicating the location of data written in the data writing area 13 is registered. The data writing area 13 stores the actually written data, and the data unwritten area 14 is an unused area where no data is written. When data written in the data writing area 13 is deleted, the area where the deleted data has been written becomes the data unwritten area 14, and when data is written in the data unwritten area 14, the area of the written data becomes It becomes the data writing area 13.
[0016]
In this system, a process of copying data written in the logical disk 1 to another logical disk 2 as a countermeasure against a failure is performed every time a fixed time elapses or at the end of daily operation. FIG. 3 is a flowchart showing the flow of processing performed by the control unit 34. When a data copy command is generated (step S1), the control unit 34 reads information written in the data management information area 12 of the logical disk 1 (step S2), and data written in the data write area 13 of the logical disk 1 Is determined (step S3). Then, the data in the data unwritten area is not copied (step S4), and the data in the data write area 13 is copied to the corresponding area in another logical disk 2 for the data write area where the data is actually written. At the same time, the data in the data management information area 12 for the write data is copied to the corresponding area of the logical disk 2 (step S5).
[0017]
In other words, the control unit 34 does not copy the OS management information area 11 and the unused data unwritten area 14, but extracts data of only the data management information area 12 and the data writing area 13 to handle the logical disk 2. Copy to the area to be used. As a result, as shown in FIG. 2, in the logical disk 2 having the OS management information 21 different from the OS management information 11 of the logical disk 1, it is a copy of the data management information area 12 and the data writing area 13 of the logical disk 1. A data management information area 22 and a data writing area 23 are created, and the remaining part remains as a data unwritten area 24.
[0018]
By copying the logical disk in this way, the OS management information area in which information for managing the logical disk from the computer 1 is stored as compared with the conventional example in which the entire logical disk 1 is copied to the logical disk 2. Therefore, the copy source logical disk 1 and the copy destination logical disk 2 can be used individually from the computer 1. Therefore, while the normal operation is resumed on the logical disk 1 after copying, another operation such as using the logical disk 2 for search purposes can be performed. Further, since the data unwritten area is not copied, the copy time can be reduced accordingly. Further, since no access is made to the data unwritten area, it is possible to avoid the error termination when there is a physical failure in the data unwritten area 24 of the copy destination logical disk 2.
[0019]
4 and 5 are schematic block diagrams showing the configuration of another embodiment of the present invention. In the system of the second embodiment shown in FIG. 4, two information storage devices 37 and 38 are connected to a computer 31 via a data transmission / reception bus 32. In this system, the logical disk 1 that is the copy source is arranged in the information storage device 37, and the logical disk 2 that is the copy destination is arranged in another information storage device 38. In this case, the control unit 37a that is program-controlled by the information storage device 37 controls the data copy process, and other operations and the like are substantially the same as those in the first embodiment described above. That is, the control unit 37a of the device 37 having the copy source logical disk 1 reads the data management information 12 and the data write area 13 of the logical disk 1 and transfers them to another information storage device 38, and the control unit 38a of this device 38. Is received in the data management information area 22 and the data writing area 23 of the logical disk 2 (see FIG. 2). The operation of the control unit 38a of the copy destination storage device 38 in this case is the same as the processing for the data read / write command from the host device, that is, the computer 31 during normal operation.
[0020]
In the third embodiment shown in FIG. 5, one information storage device 39 is connected to the computer 31, the copy source logical disk 1 is arranged in the computer 31, and the copy destination logical disk 2 is the information storage device. 39. In this embodiment, when the control unit 31a of the computer 31 having the copy source logical disk 1 reads only the data management information area 12 and the data write area 13 from the logical disk 1 and transfers them to the information storage device 39, the control unit of the apparatus 39 39a is stored in the corresponding area of the logical disk 2. As described above, the copy source and copy destination logical disks may be in the same device or in different devices.
[0021]
【The invention's effect】
As described above, according to the data copy system of the present invention, in the copy operation of the logical disk, the OS management information area for managing the logical disk is not copied from the upper part of the logical disk area. The OS management information of the original and copy destination logical disks is not the same, and the copy source and copy destination logical disks can be used individually from the same computer. In addition, since the data unwritten area where data does not exist is not copied, the processing time can be reduced, and the area corresponding to the data unwritten area in the copy destination logical disk is not accessed even if there is a physical failure. There is no error.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a schematic block diagram showing a configuration of an area of a logical disk.
FIG. 3 is a flowchart for explaining the flow of data copy work;
FIG. 4 is a schematic block diagram showing the configuration of another embodiment of the present invention.
FIG. 5 is a schematic block diagram showing the configuration of another embodiment of the present invention.
FIG. 6 is a schematic block diagram for explaining a conventional data copy operation.
[Explanation of symbols]
1 Copy source logical disk 2 Copy destination logical disk 11, 21 OS management information area 12, 22 Data management information area 13, 23 Data write area 14, 24 Data unwritten area 31 Computer 32 Data transmission / reception bus 33 Information storage device 34 Control unit 36 programs

Claims (6)

In a data copy system that copies data on a logical disk in an information storage device to another logical disk as a countermeasure against a failure, a copy source logical disk to which data has already been written, a data copy destination logical disk, and copy operation control Means and
The copy source logical disk includes an OS management information area in which information for managing the logical disk from higher-level means is recorded; a data management information area in which the location of write data in the logical disk is recorded; A data writing area in which write data from the means is recorded, and an unused data unwritten area,
The copy destination logical disk is provided with an OS management information area in which OS management information different from the copy source logical disk, which is information for managing the logical disk from higher-level means, is recorded. The disk and the copy destination logical disk are recognized by the higher-level means as different logical disks,
The copy operation control means copies the data management information area and the data write area of the copy source logical disk to the copy destination logical disk without changing the OS management information area of the copy destination logical disk, and A data copy system characterized in that the means can use data copied to the copy destination logical disk separately from the copy source logical disk . 2. The data copy system according to claim 1, wherein the copy operation control means does not copy the unwritten area of the copy source logical disk to the copy destination logical disk. system.   3. The data copy system according to claim 1, wherein the copy source logical disk and the copy destination logical disk are in the same device.   3. The data copy system according to claim 1, wherein the copy source logical disk and the copy destination logical disk are in different devices connected to each other. In a method of copying data of a logical disk in a computer or one or more information storage devices connected to the computer to another logical disk for troubleshooting,
The copy source logical disk includes an OS management information area in which information for managing the logical disk from the upper level means is recorded, a data management information area in which the location of write data is recorded in the logical disk, and the upper level Rutotomoni comprising a data write area where writing data is recorded from the unit, and a data unwritten area is unused,
The copy destination logical disk includes an OS management information area in which OS management information different from the copy source logical disk is recorded, which is information for managing the logical disk from higher-level means. And the copy destination logical disk is recognized as a different logical disk from the host means,
Without changing the OS management information area of the copy destination logical disk, only the data management information area and the data write area of the storage area of the copy source logical disk are copied to the corresponding areas of the copy destination logical disk. The data copy method is characterized in that the higher-level means can use data copied to the copy destination logical disk separately from the copy source logical disk . In a program for copying data on a logical disk in a computer or one or more information storage devices connected to the computer to another logical disk for troubleshooting,
The copy source logical disk includes an OS management information area in which information for managing the logical disk from the upper level means is recorded, a data management information area in which the location of write data is recorded in the logical disk, and the upper level A data write area in which write data from the means is recorded, and an unused data unwritten area,
The copy destination logical disk includes an OS management information area in which OS management information different from the copy source logical disk is recorded, which is information for managing the logical disk from higher-level means. And the copy destination logical disk is recognized as a different logical disk from the host means,
The program extracts only the data management information area and the data write area from the copy source logical disk area without changing the OS management information area of the copy destination logical disk, and A program for controlling the computer or the storage device to transfer to a corresponding area for copying.

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