JP2004348360A - Data reproduction preparing method and data reproducing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly recognize a generation of the reproduction of a storage device by a data processor. <P>SOLUTION: In this method for making the storage device communicatively and externally connected to the data processor to be operated under program control, and equipped with a plurality of storage parts prepare the reproduction of master data stored by the storage device, each time the reproduction of the master data is prepared, predetermined identification information for making the data processor recognize that the generation of the prepared reproduction is the latest is assigned to the storage part where the reproduction is stored, and identification information showing another generation is assigned to another storage part in which the already prepared reproduction of the master data is stored. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of creating a copy of data held by a storage device such as a so-called disk array device externally connected to a data processing device, and a data replication system for performing the method. About.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a technique for creating a copy of data in a disk array device externally connected to a data processing device such as a computer, there is a technology described in, for example, Patent Document 1 described below. This document discloses a method of managing a snapshot of a storage device system, and in a disk array device, whether or not data is updated is recorded for each address (LBA) of a storage area (LU) of copy source data.
[0003]
[Patent Document 1]
JP 2001-331378A (Page 3-7, FIG. 1-5)
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional technology, since the update status for each address is recorded in the order of arrangement of the addresses, in order for the computer to recognize which address is in the updated state, each The addresses need to be determined sequentially. Therefore, it is difficult to quickly grasp the storage area corresponding to the latest data.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a copy creation method and a data copy method capable of smoothly recognizing a storage area of the latest copy data created by a storage device externally connected to a computer on the computer side. The purpose is to provide a system.
[0006]
[Means for Solving the Problems]
A copy creation method according to the present invention is a method for creating a copy of master data held by a storage device externally communicably connected to a data processing device operating under program control and having a plurality of storage units and held in the storage device. Each time a copy of master data is created, predetermined identification information for causing the data processing device to recognize that the created copy is the latest generation is assigned to a storage unit in which the copy is stored, and Identification information indicating another generation is assigned to another storage unit in which a ready-made copy of the master data is stored.
[0007]
A data replication system according to the present invention is a data replication system including a data processing device that operates under program control and a storage device that is externally connected to the data processing device and that holds master data, wherein the storage device includes: A data replication unit that creates a copy of the master data, a plurality of storage units that hold replications of different generations from each other, and that the data replication unit has the latest generation of the created copy every time a copy is created. That is, predetermined identification information for causing the data processing device to recognize the above is allocated to the storage unit in which the copy is stored, and the identification indicating another generation is stored in another storage unit in which a ready-made copy of the master data is stored. Means for allocating information.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0009]
(Embodiment 1)
FIG. 1 is a block diagram showing a first embodiment of a data replication system for implementing a replication creation method according to the present invention. As shown in FIG. 1, a data replication system 100 according to the first embodiment includes a disk array device 1 that is a storage device, and a computer 2 that is a data processing device that operates under the control of an operating system 20 that is software for performing program control. Are connected so as to be able to communicate with each other via a connection line 50 extending from the connection portion 16 of the disk array device 1 and the disk array device connection mechanism 21 of the computer 2. The computer 2 supplies the master data to be stored in the disk array device 1 to the disk array device 1 via the connection line 50.
[0010]
The disk array device 1 includes a copy creation unit 10 that is a data copy unit that creates a copy of master data for backup processing, a master logical disk 11 that holds master data, and a copy created by the copy creation unit 10 that has a generation. It has duplicate logical disks 12 to 14 which are storage units separately stored, and a disk array device control unit 15 which controls the operation of the disk array device 1. In the present embodiment, an example is shown in which three logical disks for storing a copy of the master data are the duplicate logical disks 12 to 14. However, the number of duplicate logical disks is not limited to the number shown in this example, and can be set as appropriate. it can.
[0011]
The computer 2 recognizes each of the logical disks 11 to 14 of the disk array device 1 by a logical disk number (hereinafter, referred to as “LUN” (Logical Unit Number)) which is identification information having continuity. . In the present embodiment, “LUN.0”, “LUN.1”, “LUN.2”, and “LUN.3” are prepared as LUNs, and “LUN.0” is previously stored in the master logical disk 11. Fixedly assigned. Further, any one of “LUN · 1” to “LUN · 3” is assigned to each of the duplicate logical disks 12 to 14 by the duplicate creation unit 10.
[0012]
Each LUN assigned to the duplicate logical disks 12 to 14 is assigned so that the computer 2 can recognize the generation of the copy stored in the disk. In the present embodiment, “LUN · 1” is replaced by “LUN · 1”. LUN indicating the latest generation. For example, in the example shown in FIG. 2, the generation of the copy is set so as to sequentially transition from the newest one to the oldest one along the LUN array. In this case, the copy assigned “LUN · 1” is set here. The latest copy is stored in the logical disk 12, the copy logical disk 13 of “LUN · 2” stores the copy of one generation older than the latest copy, and the copy logical disk 14 of “LUN · 3” is stored in the logical disk 12. Stored is a copy of the oldest generation among the three generations.
[0013]
The operation of the data replication system 100 will be described with reference to the flowchart shown in FIG. Here, an example in which a new copy of the master data is created when the LUN assignment is in the state shown in FIG.
[0014]
First, the disk array device 1 determines to store a newly created copy on the duplicate logical disk 14 (Step A1). At this point, the oldest generation copy is stored in the copy logical disk 14 as shown in FIG.
[0015]
The disk array device 1 and the computer 2 perform predetermined preparation processing for creating a new copy between each other (step A2). When the preparation is completed, the computer 2 causes the computer 2 to create a copy of the master data. An instruction is given to the array device 1 (step A3). The copy creation unit 10 of the disk array device 1 creates a copy based on the master data held in the master logical disk 11, and stores this copy in the duplicate logical disk 14 determined in Step A1 (Step A4). ). Therefore, the data stored in the master logical disk 11 and the data stored in the duplicate logical disk 14 are equal.
[0016]
Further, the copy creation unit 10 confirms which disk is assigned “LUN · 1” indicating the latest generation (step A5). If it has not been assigned to any disk yet (step A6: NO), it is only necessary to assign “LUN · 1” to the newly created copy (step A8), but at this point, as shown in FIG. Since "LUN.1" has already been assigned to the duplicate logical disk 12 (step A6: YES), the LUN assignment is changed as shown in FIG. 4 (step A7). That is, “LUN · 1” is assigned to the duplicate logical disk 14 in which the new copy is stored in the step A4, and “LUN · 2” is assigned to the duplicate logical disk 12 that holds the copy that is one generation older than this. "LUN.3" is assigned to the duplicate logical disk 13 which is the oldest generation among the three generations. As a result, the computer 2 can acquire the latest copy from the duplicate logical disk 14 by specifying “LUN · 1”.
[0017]
After that, every time a master data copy is made, a predetermined “LUN.1” is assigned to the copy logical disk corresponding to the latest generation, and “LUN.2” and “LUN.2” are assigned to the other disks according to the above-described procedure. “LUN · 3” is assigned.
[0018]
The association between the LUN and the copy generation can be set as shown in FIG. 5 in addition to the above example. That is, when the latest generation is “LUN · 1” as in the example of FIG. 2, “LUN · 2” is made to correspond to the oldest generation, and “LUN · 3” is made to the next newer generation. Make it correspond. Thereby, the computer 2 can always obtain the latest copy by designating “LUN.1”, while the computer 2 designates each LUN that continues in the order of “LUN.2” and “LUN.3”. Duplicates can be acquired in order from generation to new generation.
[0019]
According to the data replication system 100 of the first embodiment, every time a copy of master data is created, a predetermined LUN (“LUN · 1”) is always allocated to the duplicate logical disk in which the copy is to be stored. Accordingly, the computer 2 can smoothly acquire the latest copy by designating a predetermined LUN without searching for the latest generation copy from the disk array device 1.
[0020]
(Embodiment 2)
FIG. 6 is a block diagram showing a second embodiment of the data replication system according to the present invention. The data replication system 200 according to the second embodiment includes a computer 3 externally connected to the disk array device 1 in addition to the same disk array device 1 and computer 2 as the data replication system 100 described in the first embodiment. Like the computer 2, the computer 3 is a data processing device that operates under program control of the operating system 30. In the data replication system 200, the computer 2 is provided as a data processing device that supplies master data to the master logical disk 11 of the disk array device 1, and the other computer 3 acquires a copy created by the disk array device 1. It is provided for. In the present embodiment, the computer 2 recognizes the master logical disk 11 but does not recognize the duplicate logical disks 12 to 14, and the computer 3 recognizes the duplicate logical disks 12 to 14 but recognizes the master logical disk 12. 11 is set not to be recognized.
[0021]
FIG. 7 shows an example of a LUN for the computer 2 and the computer 3 to recognize each disk of the disk array device 1. In the example shown in FIG. 7, the computer 2 recognizes the master logical disk 11 as “LUN · 0”. On the other hand, the computer 3 recognizes the duplicate logical disk holding the latest copy as "LUN.0", and thereafter recognizes "LUN.1" and "LUN.2" in order from the newest generation to the oldest generation. In the illustrated example, for the sake of explanation, the computers 2 and 3 use LUNs of the same format. However, if the data format is individually recognizable by each computer, a different format is used between the computers. LUN may be used.
[0022]
When instructed by the computer 2 to create a copy of the master data, the disk array device 1 changes the LUN assignment to each disk according to the same procedure as described in the first embodiment, Update the generation of the copy. The computer 3 acquires the copy created by the disk array device 1 by designating the LUN.
[0023]
Note that the association between the copy generation and the LUN recognized by the computer 3 is not limited to the example in FIG. 7 and may be set as in FIG. 8, for example. The example of FIG. 8 has the same settings as the example shown in FIG. 5 relating to the first embodiment, that is, the case where the generations of the copy are made to correspond to the LUNs continuing from the LUN indicating the latest generation in order from the oldest generation to the newest generation. It is.
[0024]
According to the data duplication system 200 of the second embodiment, the same effects as those of the data duplication system 100 of the first embodiment can be obtained, and a data processing device such as the computer 3 used to acquire a duplicate. Is added, the generation can be smoothly recognized by the LUN.
[0025]
【The invention's effect】
As described above, according to the present invention, every time a copy of master data is created, predetermined identification information is always assigned to the storage unit in which the copy is to be stored. The latest generation copy can be smoothly acquired from the storage device. Thus, when the latest copy is stored in another medium or when the copy as backup data is used for data recovery, the processing can be efficiently performed. In addition, since the generation is updated by changing the assignment of the identification information, the data processing device can recognize the new generation without moving the copy between the plurality of storage units. Thus, data corruption due to data movement can be prevented.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a data replication system according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram (part 1) for describing an example of LUN assignment in the first embodiment of the present invention.
FIG. 3 is a flowchart showing an operation procedure of the data replication system according to the first embodiment of the present invention.
FIG. 4 is an explanatory diagram (part 2) for describing an example of LUN assignment in the first embodiment of the present invention.
FIG. 5 is an explanatory diagram (part 3) for explaining an example of LUN assignment in the first embodiment of the present invention.
FIG. 6 is a block diagram illustrating a configuration of a data replication system according to a second embodiment of the present invention.
FIG. 7 is an explanatory diagram (part 1) for explaining an example of LUN assignment in the second embodiment according to the present invention.
FIG. 8 is an explanatory diagram (part 2) for describing an example of LUN assignment in the second embodiment according to the present invention.
[Explanation of symbols]
100, 200 Data replication system 1 Disk array device 2, 3 Computer 10 Replication creation unit 11 Master logical disk 12-14 Duplicated logical disk 15 Disk array device control unit 16 Connection unit 20 Operating system 21, 31, Disk array device connection mechanism 50 Connection line

Claims (6)

A method in which a storage device having a plurality of storage units externally communicably connected to a data processing device that operates under program control creates a copy of master data held in the storage device,
Every time a copy of the master data is created, predetermined identification information for causing the data processing device to recognize that the created copy is the latest generation is assigned to the storage unit where the copy is stored, and A copy creation method characterized by assigning identification information indicating another generation to another storage unit in which a ready-made copy of data is stored. 2. The method according to claim 1, wherein when assigning the identification information indicating another generation to the other storage unit, the other identification information is assigned instead of the identification information previously assigned to the other storage unit. How to make a duplicate. In advance, the continuity is given between the predetermined identification information and the other identification information, and a continuous generation sequentially transitioning from a new generation to an old generation is given to other identification information continuing to the predetermined identification information. 3. The method according to claim 2, wherein the duplicates are associated with each other. In advance, continuity is given between the predetermined identification information and the other identification information, and the other identification information continuing to the predetermined identification information includes a continuous generation sequentially shifting from an old generation to a new generation. 3. The method according to claim 2, wherein the duplicates are associated with each other. A data replication system including a data processing device that operates by program control and a storage device that is externally connected to be able to communicate with the data processing device and holds master data,
The storage device,
A data copying unit that creates a copy of the master data;
A plurality of storage units for holding copies of different generations from each other;
The data copying unit assigns, to the storage unit where the copy is stored, predetermined identification information for causing the data processing device to recognize that the generation of the created copy is the latest for each time a copy is created, Means for assigning identification information indicating another generation to another storage unit in which a ready-made copy of the master data is stored,
A data replication system comprising: The image processing apparatus further includes another data processing device externally connected to the storage device so as to be able to communicate with the storage device and acquiring a copy stored in each storage unit of the storage device based on the identification information. 5. The data replication system according to 5.

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