System and method for data copy

The present invention relates to a data copy system and a data copy method, and is particularly applied to a data copy system and a data copy method for copying (mirroring) data from a normal storage device to a secondary storage device located at a remote location from the normal storage device. It is about effective technology.

Conventionally, an information processing system including a host computer and a plurality of storage devices stores data that the user desires to be stored in the storage device for a long period of time. Then, by reading the requested data from the storage device in response to the request from the user, the data can be used for a long period of time.

Further, in the information processing system, in order to prevent the data written in the storage device from being lost, when the data is written to one storage device connected to the host computer, the same data is also sent to another storage device. It is common to write. As a method of writing one data to each of two or more storage devices in this way, for example, there is a method called remote copy.

The remote copy is a method in which data is copied between a plurality of storage device systems located at geographically separated locations without the intervention of the host computer, and the data is stored in two places. The storage device system is a system composed of a plurality of storage devices and a controller that controls the storage devices.

In the information processing system that performs remote copying, storage device systems installed at geographically separated locations are interconnected by a network line such as a dedicated line or a public line. Then, among the logical storage areas (hereinafter referred to as logical volumes) possessed by a certain storage device system, a logical volume having the same capacity as the capacity of the logical volume to be remote copied is secured in the copy destination storage device system. To. Hereinafter, the logical volume that is the target of the remote copy is referred to as a copy source logical volume, and the logical volume secured in the copy destination storage system is referred to as a copy destination logical volume.

The copy destination logical volume is formed so as to have a one-to-one correspondence with the copy source logical volume. Then, the data of the copy source logical volume is copied to the copy destination logical volume via the network line. When the data recorded in the copy source logical volume is updated, the updated data is transferred to the storage device system having the copy destination logical volume via the network line. Then, the transferred data, that is, the data updated in the copy source logical volume is copied to the copy destination logical volume. As described above, in the information processing system having the plurality of storage devices, the logical volumes having the same contents can be held by the plurality of storage devices by performing the remote copy.

Further, the remote copy has a method called an orderless guarantee type. In the unordered remote copy, when the storage device system including the copy source logical volume transmits data to the storage device system including the copy destination logical volume, the storage device system including the copy destination logical volume sends data. The next data is transmitted to the copy destination logical volume without waiting for the signal indicating that the data of is received.

Further, in the remote copy with no guarantee of order, the order in which the host computer writes data to the copy source logical volume and the order in which the data are transferred to the copy destination logical volume may be different. Therefore, in the unordered remote copy, when the host computer repeatedly writes data to the same position of the copy source logical volume based on such a property, only the last written data is displayed. It can be sent to a storage device system having the copy destination logical volume. Therefore, the amount of traffic on the network line between the copy source and copy destination storage systems can be reduced.

When the host computer manages the data written in the storage device system as a file system, it can be used to give an instruction to transfer data from the host computer to the storage device system by using the memory of the host computer. , Data transfer (write processing) to the actual storage system is performed asynchronously.

However, when data transfer from the host computer to the storage system is performed asynchronously, for example, in the event of a failure such as a power failure, only a part of the changes made to the file system, that is, the actual transfer. Only a part of all the data is written to the copy source logical volume of the storage device system, which may cause a problem that the file system is damaged.

In order to prevent such file system corruption, in other words, loss of integrity of the file system, in recent years, at least data called metadata such as inodes and directories, which are data for managing files, have been used. Even if the asynchronous write data held in the memory that has not been transferred from the host computer to the storage device system is lost due to a sudden power failure or the like, the file system is repaired after the host computer is restored. The asynchronous writing is managed by a procedure that can be performed.

A typical method for managing asynchronous writing is a method called journaling. In this method, by using special data called a journal that is different from the file system, even if some file data is lost, the file system can be prevented from being damaged (for example, Non-Patent Document 1). See.).

Further, in the remote copy without guarantee of order, the amount of data required to be transferred (copied) between the storage device systems can be reduced. However, if the written data is not transferred to the copy destination logical volume in synchronization with the writing of data from the host computer to the copy source logical volume, the copy destination logical volume is in the state intended by the host computer. There is a situation where it is not. In such a situation, there is a problem that the failure countermeasures of the file system, such as journaling, do not work effectively for the copy destination logical volume, and the file system may be damaged.

As a method of solving the problem that the file system is damaged because the failure countermeasures of the file system do not work effectively, for example, the integrity of the file system in which the host computer is stored in the copy source logical volume is used. Select a certain temporary point, send an instruction to start remote copying with no guarantee of order to the storage system that has the copy source logical volume, and then send a command to the storage system that has the copy destination logical volume. There is a way to start sending and receiving (copying) data between (see, for example, Patent Document 1). With this method, it is possible to guarantee that the data stored in the copy destination logical volume is in a consistent state as a file system.<nplcit num="1"><text>Margo Seltzer and Greg Ganger and M. Kirk McKusick and Keith Smith and Craig Soules and Christopher Stein, "Journaling Versus Soft Updates: Asynchronous Meta-data Protection in File Systems," the 2000 USENIX Annual Technical Conference</text></nplcit><patcit num="1"><text>JP-A-2002-259183</text></patcit>

<p> However, in the case of the method as described in Patent Document 1, the storage system receives information (instructions) from the host computer in order to determine when to start the unordered remote copy. I need to receive it. Therefore, in an information processing system that does not assume the unordered remote copy, there is a problem that software and hardware necessary for the host computer must be newly introduced.</p><p> An object of the present invention is that the storage system does not need to exchange information with the host computer when performing unordered remote copying, and by using information unique to the file system, a plurality of storage systems can be used. The purpose is to provide a technology that can maintain a consistent state as a file system between them and recover data in another storage system even if the data in one storage system is damaged. ..</p><p> The above and other objects and novel features of the present invention will become apparent in the description and accompanying drawings herein.</p>

<p> The outline of the invention disclosed in the present application will be described as follows. (1) A host computer, a normal storage device system that is connected to the host computer and records and holds data from the host computer, and a data that is connected to the normal storage device and is held by the normal storage device system. The primary storage system includes a secondary storage system that records and holds a copy, and the normal storage system includes a storage device that has a main logical volume that records and holds data from a host computer, and data from the host computer to the main logical volume. The sub-storage system includes a control device that controls writing and copying of data (logical volume) between the sub-storage systems, and the sub-storage system records and holds a copy of the main logical volume of the primary storage system. A data copy system including a storage device having a logical volume and a control device for controlling copying of data (logical volume) performed between the normal storage device system, and the storage device of the normal storage device system is The control device of the primary storage device system includes the main logical volume and a snapshot management means for managing a snapshot recording the state of the main logical volume used when copying data to the secondary storage device system. Consistency checking means for checking the integrity of the file system of the main logical volume of the primary storage device system, remote copy control means for controlling data copying (remote copy) between the secondary storage device system, and the like. The process of writing data from the primary host computer to the main logical volume, the process of causing the consistency check means to check the consistency, the process of creating a snapshot recording the state of the main logical volume, and the remote copy control means. The data processing means for performing each process of creating copy data to be transmitted to the sub-storage device system via the sub-storage device system is provided, and the storage device of the sub-storage device system includes the logical volume and the main of the normal storage device system. When copying a logical volume to the logical volume, take a snapshot that records the state of the logical volume before copying.The control device of the sub-storage system includes a snapshot management means for managing, and executes the remote copy control means for controlling the copy (remote copy) of data to and from the normal storage device and the remote copy. Previously, the process of creating a snapshot recording the state of the logical volume, the process of applying (copying) the data of the main logical volume transmitted from the positive storage system to the logical volume, and the remote copy failed. It is a data copy system including data processing means for performing each process of restoring the logical volume using the snapshot.</p><p> (2) A host computer, a normal storage device system connected to the host computer and recording and holding data from the host computer, and data connected to the normal storage device and held by the normal storage device system. A secondary storage system that records and holds a copy is provided, and the normal storage system includes a storage device that has a main logical volume that records and holds data from a host computer, and a storage device that records and holds data from the host computer to the main logical volume. The sub-storage system includes a control device that controls writing and copying of data (logical volume) between the sub-storage systems, and the sub-storage system records and holds a copy of the main logical volume of the primary storage system. A data copy method by a data copy system including a storage device having a logical volume and a control device for controlling copying of data (logical volume) performed between the positive storage device system, and the positive from the host computer. Step 1 of checking the consistency of the main logical volume as a file system when the writing of data to the main logical volume of the storage device is completed, and the above when the consistency of the main logical volume is guaranteed. Using the snapshot created in step 2 for creating a snapshot recording the state of the main logical volume and the snapshot created in step 2, a remote copy is executed between the primary storage system and the secondary storage system, and the remote copy is executed. It has step 3 of making the state of the logical volume of the secondary storage system the same as that of the main logical volume, and the step 3 is the main of the primary storage system using the snapshot created in step 2. Step 4 of transferring the data indicating the state of the logical volume to the sub-storage device system, step 5 of creating a snapshot recording the state of the logical volume of the sub-storage device system before the execution of the remote copy, and the step 5 of the step. A device having step 6 of applying the data transferred in step 4 to the logical volume of the sub-storage system.This is a data copy method.</p>

<p> In the data copy method of the present invention, as described in (1) above, the control means of the positive storage device system is provided with a data processing means for determining the execution time of remote copy. Therefore, the remote copy can be executed only by the normal storage device system and the sub-storage device system without instructing the execution time of the remote copy from the host computer.</p><p> Further, when performing remote copying of data (main logical volume) using the data copy system described in (1) above, for example, as described in (2) above, the main logic of the positive storage device system. Executed when the volume is consistent. At this time, the consistency of the mainframe may be checked, for example, when the writing of data from the host computer to the mainframe is completed. In this way, after executing the remote copy, the logical volume of the sub-storage system is in a state of being consistent as a file system. Therefore, for example, even if the data of the main logical volume of the primary storage system is damaged, the damaged data can be easily recovered by using the data recorded and held in the logical volume of the secondary storage system. can do.</p><p> Further, when the remote copy is executed by the method described in (2) above, the step 4 is a snapshot recording the state of the main logical volume of the positive storage device system created at the time of the previous remote copy execution. And the difference data of the snapshot created in step 2 may be transferred. By doing so, it is possible to reduce the amount of data to be transferred from the primary storage system to the secondary storage system when remote copying is executed, the copy can be performed in a short time, and the load on the network or other lines is reduced. can do.</p><p> Further, when the remote copy is executed by the method described in (2) above, a failure occurs in the network connecting the normal storage device system and the sub storage device system during the execution, and the remote copy is normally performed. It may not be completed. In that case, the logical volume of the sub-storage system becomes inconsistent as a file system. Therefore, in step 3, when the process of step 6 fails, the logical volume of the sub-storage system is restored to the state before the remote copy is executed by using the snapshot created in step 5. It is preferable to have step 7. By doing so, even if the remote copy fails, the logical volume of the sub-storage system can be restored to a consistent state as a file system. Therefore, for example, even if the data of the main logical volume of the positive storage device system is damaged, the data can be easily recovered.</p><p> Further, when the remote copy is executed by the method described in (2) above, the main logical volume at the latest time among the times when the consistency of the main logical volume of the positive storage device system is guaranteed, In other words, the state of the main logical volume at the time of the last successful remote copy may be recorded on a magnetic, electrical, or optical recording medium. When a failure occurs in a part other than the primary storage system and the secondary storage system, it is necessary to synchronize the logical volume again between the primary storage system and the secondary storage system after recovering from the failure. There is. Therefore, if the state of the main logical volume at the time of the last successful remote copy is recorded in the recording medium, only the data changed by the host computer from that time can be sent to the sub-storage system. The data of the main logical volume of the primary storage system and the logical volume of the secondary storage system can be matched, and the recovery work at the time of failure can be speeded up.</p><p> Hereinafter, the present invention will be described in detail together with embodiments (Examples) with reference to the drawings. In all the drawings for explaining the examples, those having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted.</p>

In the data copy system of the present invention, the logical volume of the mainframe storage system that stores data from the mainframe computer is managed as a file system. Then, the positive storage device system checks the integrity of the file system of the logical volume when the writing of data from the positive host computer to the logical volume is completed. At this time, if it is determined that the file system of the logical volume is consistent, the primary storage device system transfers the data of the logical volume to the secondary storage device system, and the logical volume of the secondary storage device system. Copy to.

[Embodiment]

FIG. 1 is a schematic diagram showing a schematic configuration of a data copy system according to an embodiment of the present invention. In FIG. 1, 1A is the primary host computer, 1B is the secondary host computer, 2 is the primary storage system, 201 is the storage device, 201A is the main logical volume, 201B is the snapshot management means, 202 is the control device, and 202A is the integrity. Inspection means, 202B is remote copy control means, 202C is data processing means, 202D is buffer, 3 is network, 4 is secondary storage system, 401 is storage, 401A is logical volume, 401B is snapshot management means, 402 is The control device, 402A is a remote copy control means, 402B is a data processing means, and 402C is a buffer.

As shown in FIG. 1, the data copy system of the present embodiment is connected to two host computers, a primary host computer 1A and a secondary host computer 1B, with the primary host computer 1A by a cable, and is connected to the primary host computer 1A by a cable. A copy of the data held by the positive storage device system 2 which is connected to the regular storage device system 2 for recording and holding the data from 1A via a network 3 such as the Internet. It is composed of a sub-storage device system 4 that holds records. At this time, the sub-storage device system 4 is a storage device system that replaces the normal storage device system 2 when a failure occurs in the normal storage device system 2, and is held by the normal storage device system 2. The same data as the data is retained. At this time, the secondary host computer 1B is a host computer that operates in place of the primary host computer 1A when a failure occurs in the primary host computer 1A. For example, as shown in FIG. 1, the secondary host computer 1B is the secondary computer. It is connected to the storage system 4 with a cable.

Further, as shown in FIG. 1, the positive storage device system 2 includes a storage device 201 having a main logical volume 201A that records and holds data from the positive host computer 1A, and the main logic from the positive host computer 1A. The control device 202 controls the writing of data to the volume 201A and the copying of data (logical volume) to and from the sub-storage device system 4. At this time, it is assumed that the main logical volume 201A is managed as a file system.

At this time, the storage device 201 of the normal storage device system 2 records the state of the main logical volume 201A used when copying data to the sub storage device system 4._nA snapshot management means 201B for managing (n 1) is provided.

Further, the control device 202 of the normal storage device system 2 is between the consistency check means 202A for checking the consistency of the file system of the main logical volume 201A of the normal storage device system 2 and the sub storage device system 4. A process of writing data from the primary host computer 1A to the main logical volume 201A, and a process of causing the consistency checking means 202A to check the consistency. A data processing means that performs each process of creating a snapshot SSM recording the state of the main logical volume 201A and creating copy data to be transmitted to the sub-storage system 4 via the remote copy control means 201B. Equipped with 202C. At this time, the control means 202 of the positive storage device system 2, in addition to the respective means, checks the consistency of the main logical volume 201A and between the normal storage device system 2 and the sub storage device system 4. It is provided with a buffer 202D that temporarily holds the data sent from the positive host computer 1A while executing the remote copy in.

Further, the data processing means 202C issues an instruction to cause the consistency checking means 202A to check the consistency when the writing of data from the positive host computer 1A to the main logical volume 201A is completed. Further, the data processing means 202C starts remote copying to the remote copy control means 201B when it is guaranteed that the main logical volume 201A is consistent as a result of the inspection by the consistency inspection means 202A. Give an order to make it.

On the other hand, as shown in FIG. 1, the sub-storage device system 4 includes a storage device 401 having a logical volume 401A that records and holds a copy of the main logical volume 201A of the normal storage device system 2, and the normal storage device system. It consists of a control device 402 that controls copying of data (logical volume) to and from 2.

At this time, when the storage device 401 of the sub storage device system 4 copies the state of the main logical volume 201A of the primary storage device system 2 to the logical volume 401A, the storage device 401 changes the state of the logical volume 401A before copying to the logical volume 401A. Recorded snapshot SSC_mA snapshot management means 401B for managing (m 1) is provided.

Further, the control device 402 of the sub-storage device system 4 has a remote copy control means 402A that controls copying (remote copy) of data to and from the normal storage device system 2, and before executing the remote copy. , A process of creating a snapshot SSC recording the state of the logical volume 401A, a process of applying (copying) the data of the main logical volume 201A transmitted from the positive storage device system 2 to the logical volume 401A, the remote copy. It is provided with a data processing means 402B that performs each process of restoring the logical volume 401 to a consistent state by using the snapshot SSC when the failure occurs. At this time, in addition to the above means, the control device 402 of the sub-storage system 4 receives the data sent from the normal storage system 2 while creating the snapshot SSC of the logical volume 401A. A buffer 402C for temporarily holding the buffer 402C is provided.

2 to 11 are schematic views for explaining a data copying method using the data copy system of the present embodiment, and FIG. 2 is a flow showing an overall processing procedure of the control means of the positive storage system. Figure, Figure 3 shows the processing on the system in the step of checking the integrity, Figure 4 shows the processing procedure of the positive storage system in the step of executing the remote copy, and Figure 5 creates a snapshot. A diagram showing the processing on the system in the step, FIG. 6 is a diagram showing the processing on the system in the step of transmitting data from the positive storage device system, and FIG. 7 is a diagram showing the processing procedure of the sub-storage system in the step of executing the remote copy. The flow charts shown, FIGS. 8 and 9 show the processing on the system in the step of receiving data in the sub-storage system, FIG. 10 shows an example of the processing after the remote copy is completed, and FIG. 11 shows the remote. It is a figure which shows an example of the data restoration method at the time of copy failure.

In the data copy system of the present embodiment, the determination of the timing of remote copying of the data of the main logical volume 201A of the primary storage device system 2 to the logical volume 401A of the secondary storage device system 4 is controlled by the positive storage device system 2. Device 202 is determined. In the control device 202 of the normal storage system 2, for example, as shown in FIG. 2, whether or not the writing of data from the positive host computer 1A to the main logical volume 201A of the normal storage system 2 is completed is completed. As a criterion, determine when to execute the remote copy (step 501). The step 501 is performed by the data processing means 202C. At this time, for example, if data is being written, it waits until the writing is completed. Further, when the data is not written, the next writing is performed and the data is waited until the end.

When the writing of data from the primary host computer 1A to the main logical volume 201A is completed, the integrity of the main logical volume 201A is checked (step 502). In step 502, when the data processing means 202C confirms the end of writing the data, first, for example, as shown in FIG. 3, the data processing means 202C orders the consistency checking means 202A to perform an inspection. .. Upon receiving the command from the data processing means 202C, the consistency checking means 202A checks the consistency of the file system of the main logical volume 201A, and returns the checked result to the data processing means 202C. Further, when data is written from the positive host computer 1A to the mainframe 201A while checking the consistency of the mainframe 201A, for example, as shown in FIG. 3, the data is written to the mainframe 201A. The data transferred from the positive host computer 1A is temporarily saved in the buffer 202D.

Upon receiving the inspection result from the consistency inspection means 202A, the data processing means 202C determines from the result whether or not the file system of the main logical volume is consistent (step 503). At this time, if the consistency is not obtained, do nothing and wait until the next writing.

If it is determined in step 503 that the consistency is achieved, then it is determined whether or not remote copying is possible with the sub-storage system 4 (step 504). In step 504, for example, as shown in FIG. 3, the data processing means 202C sends an instruction to the remote copy control means 202B to confirm whether remote copying is possible. Upon receiving the confirmation command, for example, as shown in FIG. 3, is the remote copy control means 202B capable of remote copying by attempting communication with the remote copy control means 402A of the sub-storage system 4. Confirm and return the result to the data processing means 202C. If the confirmation result received by the data processing means 202C is, for example, that the network 3 or the sub-storage system 4 has a failure and the remote copy cannot be performed, the remote copy must be executed now. Judge and wait until the next write.

If it is determined in step 504 that the remote copy can be executed, then the remote copy is executed (step 505).

In step 505 of executing the remote copy, first, as shown in FIG. 4, the control device 202 of the positive storage device system 2 stops writing from the positive host computer 1A to the main logical volume 201A (step). 5052A). Then, the snapshot SSM held in the snapshot management means 201B of the storage device 201 of the positive storage device system 2_nSnapshot SSM (n 1)_{n + 1}(Step 5052B).

After the processing of step 5052A and step 5052B is completed, the snapshot SSM recording the current state of the main logical volume 201A to be remotely copied is then processed.₁(Step 5052C). The step 5052C is performed by the data processing means 202C, for example, as shown in FIG.

After the processing of step 5052C is completed, the sub-storage system 4 is instructed to start remote copying, and the primary host computer 1A transfers the primary storage system 2 to the main logical volume 201A. Resume writing data (step 5052D). In step 5052D, for example, as shown in FIG. 6, the data processing means 202C sends a remote copy start instruction to the remote copy control means 202B in the control device 202 of the positive storage system 2. Then, the remote copy control means 202B in the positive storage system 2 transmits the remote copy start command to the remote copy control means 402A in the control device 402 of the sub storage system 4 via the network 3. To do. In addition, the remote copy is a snapshot SSM in the positive storage system 2.₁Because it is done using, the snapshot SSM₁Data may be written to the main logical volume 201A as long as the data is created. Therefore, as shown in FIG. 6, the data transferred from the positive host computer 1A and the data saved in the buffer 202D are written to the main logical volume 201A.

After the processing of step 5052D is completed, the snapshot SSM managed by the snapshot management means 201B is then performed.₁And SSM₂The difference data of the above is created and transmitted to the sub-storage system 4 (step 5052E). The snapshot SSM₂Is SSM before this remote copy is started₁That is, it is a snapshot recording the state of the main logical volume 201A at the time of the previous remote copy. That is, before starting the remote copy this time, the logical volume 401A in the storage device 401 of the sub storage device system 4 is the snapshot SSM.₂It is in the same state as. Therefore, the snapshot SSM managed by the snapshot management means 201B₁And SSM₂By transmitting only the difference data of the above, that is, the data updated from the time of the previous remote copy execution to the time of the current remote copy execution to the sub-storage device system 4, the amount of data transfer can be reduced, and the network can be reduced. The load applied to 3 can be reduced.

On the other hand, as shown in FIG. 7, the control device 402 of the sub storage device system 4 waits for the remote copy start instruction from the normal storage device system 2 (step 5054A). Then, as shown in FIG. 6, when the remote copy control means 402A in the control device 402 of the sub-storage system 4 receives the remote copy start instruction, the instruction is transferred to the data processing means 402B. Remote copy is started.

At this time, the snapshot management means 401B of the storage device 401 of the sub-storage device system 4 uses the snapshot SSC._mIf (m 1) is held, first, the snapshot SSC_mSSC_{m + 1}(Step 5054B). Then, after the processing of step 5054B is completed, the snapshot SSC recording the current state of the logical volume 401A in the storage device 401 of the sub storage device system 4 is then performed.₁(Step 5054C). The processing of step 5054B and step 5054C is performed, for example, via the data processing means 402B as shown in FIG. Further, when the difference data transmitted from the positive storage device system 2 is received while the processes of step 5054B and step 5054C are being executed, the difference data is stored in the buffer 402C as shown in FIG. Temporarily evacuate.

After the processes of step 5054B and step 5054C are completed, next, the difference data transmitted from the positive storage device system 2 is applied to the logical volume 401A, and files are added, deleted, and the like (step 5054D). The step 5054D is performed via the data processing means 402B, as shown in FIG. At this time, if a part of the difference data is saved in the buffer 402C, that data is also applied.

When the process of step 5054D, that is, the application (writing) of the difference data transmitted from the normal storage device system 2 is completed, the write completion notification is then returned to the normal storage device system 2 ( Step 5054E).

Upon receiving the write completion notification transmitted from the sub-storage system 4, the normal storage system 2 transmits a remote copy completion command to the sub-storage system 4, as shown in FIG. (Step 5052F). The step 5052F is performed by the remote copy control means 202B in the positive storage system 2, for example, as shown in FIG. Then, when the remote copy control means 202B in the positive storage device system 2 transmits the remote copy completion command, the data processing means 202C is notified that the remote copy is completed. After the remote copy is completed, the snapshot SSM held by the snapshot management means 201B in the positive storage system 2_nOf (n 1), SSM required to create difference data in the next remote copy₁Other snapshots SSM_n(n 2) is unnecessary. Therefore, after the remote copy is completed, the data processing means 202C finally holds the snapshot held by the snapshot management means 201B in the positive storage system 2 as shown in FIGS. 4 and 10. Shot SSM_nOf (n 2), unnecessary snapshots may be deleted (step 5052G).

On the other hand, in the sub-storage system 4, after the processes of step 5054D and step 5054E are completed, as shown in FIG. 7, the remote copy completion command from the normal storage system is awaited (step 5054F). Then, when the remote copy completion command is received, the remote copy ends, and the sub-storage system 4 waits for the next remote copy start instruction. If the remote copy is completed normally, the snapshot SSC held by the snapshot management means 401B in the sub-storage system 4 is used._m(m 1) is unnecessary. Therefore, as shown in FIGS. 7 and 10, the snapshot SSC held by the snapshot management means 401B in the sub-storage system 4_mMay be deleted (step 5054G).

Further, after the processing of step 5054D and step 5054E is completed, the remote copy completion command may not be received from the positive storage device system 2 due to, for example, a failure of the network 3. In this case, the logical volume 401A in the sub-storage system 4 is in a state where the consistency as a file system cannot be guaranteed. Therefore, if the remote copy completion command cannot be received, for example, as shown in FIGS. 7 and 11, the snapshot SSC₁Is used to restore the logical volume 401A in the sub-storage system 4 to the state before the start of remote copy, that is, the state in which the file system is consistent (step 5054H). Then, if necessary, for example, after processing the step 5054G, the sub-storage system 4 waits until the next remote copy start instruction is received.

As described above, according to the data copy method using the data copy system of the present embodiment, the remote copy can be transferred to the primary host computer 1A by determining the execution time of the remote copy in the positive storage system 2. It is not necessary to install software or hardware to indicate the execution time.

Further, by using the state in which the main logical volume 201A in the primary storage device system 2 is consistent as a file system as a criterion for determining the execution time of the remote copy, the logical volume in the secondary storage device system 4 is used. The integrity of the 401A's file system can also be guaranteed. Therefore, even if the data in the positive storage device system 2 is damaged, the data can be easily recovered in the secondary storage device system 4.

Although the present invention has been specifically described above based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist thereof. is there.

For example, when the remote copy is executed by the method described in the above embodiment, the main logical volume 201A of the positive storage system 2 is guaranteed to be consistent, in other words, the latest main logical volume. And, the state of the main logical volume at the time of the last successful remote copy may be recorded on a magnetic, electrical, or optical recording medium. When a failure occurs in a part other than the normal storage system 2 and the sub storage system 4, after recovering from the failure, the logical volume is again between the normal storage system 2 and the sub storage system 4. It is necessary to synchronize 201A and 401A. Therefore, if the state of the main logical volume 201A at the time of the last successful remote copy is recorded in the recording medium, only the data changed by the host computer 1A from that time is stored in the sub storage system 4. The data of the main logical volume 201A of the primary storage system 2 and the logical volume 401A of the sub-storage system 4 can be matched just by sending the data, and the recovery work at the time of failure can be speeded up.

<figref num="1">It is a schematic diagram which shows the schematic structure of the data copy system of one Embodiment by this invention.</figref><figref num="2">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the flow diagram which shows the overall processing procedure of the control means of a positive storage apparatus system.</figref><figref num="3">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the figure which shows the process on the system in the step of checking the consistency.</figref><figref num="4">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the flow diagram which shows the processing procedure of the positive storage apparatus system in the step of executing remote copy.</figref><figref num="5">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the figure which shows the process on the system in the step of making a snapshot.</figref><figref num="6">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the figure which shows the process on the system in the step of transmitting data from a positive storage apparatus system .</figref><figref num="7">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the flow diagram which shows the processing procedure of the auxiliary storage system in the step which executes a remote copy.</figref><figref num="8">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the figure which shows the process on the system in the step of receiving data in a sub-storage system.</figref><figref num="9">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the figure which shows the process on the system in the step of receiving data in a sub-storage system.</figref><figref num="10">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the figure which shows an example of the processing after the remote copy is completed.</figref><figref num="11">It is a schematic diagram for demonstrating the data copy method using the data copy system of this embodiment, and is the figure which shows an example of the data restoration method at the time of remote copy failure.</figref>

Code description

1A ... Primary host computer 1B ... Secondary host computer 2 ... Primary storage system 201 ... Storage 201A ... Mainframe volume 201B ... Snapshot management means 202 ... Control device 202A ... Consistency check means 202B ... Remote copy control means 202C ... Data processing means 202D ... Buffer 3 ... Network 4 ... Secondary storage system 401 ... Storage 401A ... Logical Volume 401B ... Snapshot Management Means 402 ... Control Device 402A ... Remote Copy Control Means 402B ... Data Processing Means 402C ... Buffer