JP7358809B2 - Storage control device, storage control program and storage system - Google Patents

Description

The present invention relates to a storage control device, a storage control program, and a storage system.

BACKGROUND ART Conventionally, as a measure against loss of business volume data due to disasters, etc., backup to a remote site has been performed using the copy function of a storage device. If a copy is performed directly from a business volume to a volume on a storage device at a remote site, I/O (Input/Output) performance to the business volume may be affected.

For this reason, there are cases where a snapshot of the business volume, that is, a copy of the data at a point in time, is created in the same storage device as the business volume, and the data is transferred from the created replicated volume to a remote site.

As a prior art, for example, there is a storage system that performs a primary/secondary switching process of a storage control device in the event of a system failure. Furthermore, there is a storage device that uses a snapshot function to create a remote copy.

Japanese Patent Application Publication No. 2007-213345 Japanese Patent Application Publication No. 2005-267569

However, with the conventional technology, backup data stored at a remote site cannot be made referenceable from a host server or the like while ensuring redundancy.

In one aspect, the present invention aims to enable backup data to be referenced while ensuring redundancy.

In one embodiment, a first storage device includes a primary volume and a first volume to which a snapshot of the primary volume is created; a secondary volume to which data of the snapshot of the primary volume is remotely copied; A storage control device that performs copy control of a storage system including a second storage device having a second volume in which a snapshot of a volume is created, and in response to receiving a backup data reference request, Create a third volume in which a snapshot of the primary volume is created and a fourth volume in which a snapshot of the secondary volume is created, and create a snapshot from the primary volume to the first volume and from the first volume. Stop the backup process of the primary volume using the remote copy to the secondary volume and the snapshot from the secondary volume to the second volume, and perform the snapshot from the primary volume to the third volume. There is provided a storage control device having a control unit that starts backup processing of the primary volume using a remote copy from a third volume to the secondary volume and a snapshot from the secondary volume to the fourth volume. Ru.

According to one aspect of the present invention, it is possible to make backup data referable while ensuring redundancy.

FIG. 1 is an explanatory diagram showing an example of a system configuration of a storage system according to an embodiment. FIG. 2 is an explanatory diagram showing an example of data backup. FIG. 3A is an explanatory diagram (Part 1) showing an example of copy control when referring to backup data. FIG. 3B is an explanatory diagram (part 2) showing an example of copy control when referring to backup data. FIG. 3C is an explanatory diagram (part 3) showing an example of copy control when referring to backup data. FIG. 4A is an explanatory diagram showing an example of the storage contents of the copy session table 400(P). FIG. 4B is an explanatory diagram showing an example of the storage contents of the copy session table 400(S). FIG. 5A is an explanatory diagram showing an example of the stored contents of the session relationship table 500(P). FIG. 5B is an explanatory diagram showing an example of the stored contents of the session relationship table 500(S). FIG. 6 is a block diagram showing an example of the functional configuration of the master node M. FIG. 7 is an explanatory diagram showing an example of the operation when referring to backup data. FIG. 8A is an explanatory diagram (part 1) illustrating an example of the operation at the end of referencing backup data. FIG. 8B is an explanatory diagram (Part 2) illustrating an example of the operation at the end of referencing backup data. FIG. 8C is an explanatory diagram (part 3) illustrating an example of the operation at the end of referencing backup data. FIG. 9 is a flowchart illustrating an example of the backup processing procedure of the master node M. FIG. 10 is a flowchart illustrating an example of the advance preparation processing procedure of the master node M. FIG. 11 is a flowchart illustrating an example of the backup data reference processing procedure of the master node M. FIG. 12 is a flowchart illustrating an example of the post-processing procedure of the master node M.

Embodiments of a storage control device, a storage control program, and a storage system according to the present invention will be described in detail below with reference to the drawings.

(Embodiment)
FIG. 1 is an explanatory diagram showing an example of a system configuration of a storage system according to an embodiment. In FIG. 1, a storage system 100 includes a storage device 101 and a storage device 102. In the storage system 100, a storage device 101 and a storage device 102 are connected via a wired or wireless network 110. The network 110 is, for example, a LAN (Local Area Network), a WAN (Wide Area Network), the Internet, or the like.

The storage device 101 is a copy source storage device that stores data to be backed up, and is a so-called primary storage. The storage device 102 is a copy destination storage device to which data to be backed up is copied, and is a so-called secondary storage.

The host device 103 is a higher-level device connected to the storage system 100. For example, the host device 103 performs business processing using volumes created on the storage device 101. The host device 103 is realized by, for example, a server, a PC (Personal Computer), or the like.

Each storage device 101, 102 has a remote copy function. Remote copy is a function that realizes inter-box copy at a remote location. In remote copying, for example, when periodically transferring data from a copy source (volume) to a copy destination (volume), first transfer the data from the copy source at the start point to the copy destination, and then transfer the updated data to the copy source. The procedure is to sequentially transfer the files to the copy destination.

Here, the storage devices 101 and 102 include one or more nodes 120 and one or more disks 130. The node 120 is a storage control device that manages resources such as the disk 130 and memory 122, and performs copy control. The node 120 includes a CPU (Central Processing Unit) 121, a memory 122, and a communication I/F (Interface) 123. Further, each component is connected to each other by a bus 124.

The CPU 121 is in charge of overall control of the node 120. CPU 121 may have multiple cores. The memory 122 includes, for example, DRAM (Dynamic Random Access Memory) and flash ROM (Read Only Memory). Specifically, for example, a flash ROM stores various programs. The DRAM is a volatile memory used as a work area for the CPU 121, and stores, for example, user data being processed and control information. The program stored in the memory 122 is loaded into the CPU 121 and causes the CPU 121 to execute the coded processing.

The communication I/F 123 is connected to the network 110 and the like, and is connected to other computers via the network 110 and the like. The communication I/F 123 serves as an interface between the network 110 and the like and the inside of the node, and controls input/output of data from other computers. For the communication I/F 123, for example, a CA (Channel Adapter) or a LAN adapter can be used.

Furthermore, in the storage system 100, the host device 103 is connected to the storage device 101 of the storage devices 101 and 102. For example, the host device 103 is connected to the storage device 101 using FC (Fibre Channel) or iSCSI (Internet Small Computer System Interface).

The disk 130 is an example of a storage that stores data, and is a nonvolatile storage device that stores user data and control information. The disk 130 is, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The disks 130 may all be HDDs or SSDs, or may include a mixture of HDDs and SSDs.

Here, there are cases where it is desired to refer to backup data in the secondary storage from a host server (for example, the host device 103) connected to the primary storage. In this case, in order to make the backup data referable, for example, remote copying from the primary storage to the secondary storage is suspended (stopped) and a virtual volume is created on the primary storage.

Users can refer to backup data by accessing the virtual volume on the primary storage. Furthermore, once the backup data has been referenced, the virtual volume on the primary storage is deleted, and remote copying from the primary storage to the secondary storage is restarted.

Note that the reason for referencing backup data from a host server connected to a primary storage is that, for security reasons, the host server is not allowed to directly access the secondary storage. Additionally, because the secondary storage is located far away, the host server does not directly access the secondary storage due to cost considerations.

However, when referring to backup data, if remote copying from primary storage to secondary storage is stopped, backup processing of the primary storage is interrupted, making it impossible to ensure data redundancy.

For example, when data stored in primary storage is found to be infected with a virus, all data stored in secondary storage may be scanned for viruses in order to check whether backup data is infected with a virus. Depending on the amount of backup data, virus scanning may take several days.

In such a case, if the primary storage goes down while the backup data is being referenced, the data in the primary storage will not be able to be properly restored because the data from the previous regular backup cannot be secured. In other words, only data from many generations ago (backup data being referenced) can be secured.

Therefore, in this embodiment, backup data stored in the storage device 102 (secondary storage) can be referenced from the host device 103 connected to the storage device 101 (primary storage) while ensuring redundancy. The storage control device (node 120) will be explained.

(Data backup example)
First, an example of data backup in the storage system 100 will be described. Here, the data in the storage device 101 is remotely copied to the storage device 102 to back up the data.

FIG. 2 is an explanatory diagram showing an example of data backup. In FIG. 2, the box ID is an identifier that identifies each storage device 101, 102. Here, the box ID of the storage device 101 is "A". Furthermore, the box ID of the storage device 102 is "B".

The volume (PV) is a primary volume (copy source volume) created in the storage device 101. A volume is a storage area that is a management unit of each storage device 101, 102. A volume may be one or more physical storage devices, or may be a LUN (Logical Unit Number) that is a logical storage device. For example, the volume (PV) is a business volume.

In the example of FIG. 2, the volume (PV) is LUN #1. The (number) in LUN# (number) is the volume ID. The volume ID is an identifier that uniquely identifies a volume in each storage device 101, 102. The volume (SV) is a secondary volume (copy destination volume) created in the storage device 102. In the example of FIG. 2, the volume (SV) is LUN #11.

Note that PV is an abbreviation for Primary-Volume. SV is an abbreviation for Secondary-Volume.

Here, when backing up data from volume (PV) to volume (SV), if you directly copy data from volume (PV) to volume (SV), volume (P -V) may be affected. Therefore, the storage device 101 creates a snapshot of the volume (PV) in the volume (P-Snap) within its own device, and creates a remote snapshot from the created volume (P-Snap) to the volume (SV). Make a copy.

A snapshot is a logical copy of data at a point in time. For example, when updating data, a snapshot is created using the so-called copy-on-write method, in which the state before the update of the data part to be updated is copied and the state before the update is retained along with the original unupdated part. be done. In the example of FIG. 2, the volume (P-Snap) is LUN #2.

Furthermore, if a communication failure occurs during remote copying from a volume (P-Snap) to a volume (SV), the volume (SV) is guaranteed to be in the same state as the volume (P-Snap). However, there is a possibility that the volume (SV) may become unusable. Therefore, after completing the remote copy from the volume (P-Snap) to the volume (SV), the storage device 102 creates a snapshot of the volume (SV) in the volume (S-Snap) within its own device. do. In the example of FIG. 2, the volume (S-Snap) is LUN #12.

Thereby, it is possible to back up the data of the volume (PV) while suppressing the influence on the I/O performance of the volume (PV). Furthermore, in consideration of communication failures during remote copying, data in volumes (SVs) can be backed up on the remote site side as well.

Note that in FIG. 2, the session ID is an identifier that identifies a copy session. A copy session is a copy execution unit. Further, REC represents remote copy.

(Example of copy control when referencing backup data)
Next, an example of copy control when referring to backup data in the storage system 100 will be described.

In the following description, among the nodes 120 within the storage apparatus 101, the node 120 that performs copy control of the storage system 100 may be referred to as a "master node M."

FIGS. 3A, 3B, and 3C are explanatory diagrams showing examples of copy control when referring to backup data. In FIG. 3A, first, the master node M creates a volume (P-Snap') and a volume (S-Snap') in response to receiving a backup data reference request.

Here, the volume (P-Snap') is a volume in which a snapshot of the volume (PV) is created, and is different from the volume (P-Snap). A volume (S-Snap') is a volume in which a snapshot of a volume (SV) is created, and is different from a volume (S-Snap). The volume (P-Snap') is, for example, LUN #3. The volume (S-Snap') is, for example, LUN #13.

Specifically, for example, the master node M creates a volume (P-Snap') on the storage device 101. The master node M also sends a volume (S-Snap') creation instruction to the storage device 102. When the node 120 of the storage device 102 receives the volume (S-Snap') creation instruction from the master node M, it creates the volume (S-Snap') on the storage device 102.

Next, the master node M performs a snapshot from a volume (PV) to a volume (P-Snap), a remote copy from a volume (P-Snap) to a volume (SV), and a remote copy of a volume (S-V) to a volume (S-V). The backup process of the volume (PV) using the snapshot from V) to the volume (S-Snap) is stopped.

In the following description, a snapshot from a volume (PV) to a volume (P-Snap) may be referred to as a "snapshot (PV/P-Snap)." Further, a snapshot from a volume (SV) to a volume (S-Snap) is sometimes referred to as a "snapshot (SV/S-Snap)." Further, remote copying from a volume (P-Snap) to a volume (SV) may be referred to as a "remote copy (REC)."

In FIG. 3B, the master node M performs a snapshot from the volume (PV) to the volume (P-Snap'), a remote copy from the volume (P-Snap') to the volume (SV), Then, backup processing of the volume (PV) is started using the snapshot from the volume (SV) to the volume (S-Snap').

In the following description, a snapshot from a volume (PV) to a volume (P-Snap') may be referred to as a "snapshot (PV/P-Snap')." Further, a snapshot from a volume (SV) to a volume (S-Snap') is sometimes referred to as a "snapshot (SV/S-Snap')." Furthermore, remote copying from a volume (P-Snap') to a volume (SV) may be referred to as a "remote copy (REC')."

As a result, a new generation snapshot volume and snapshot session are created in both the storage devices 101 and 102, and backup processing of the volume (PV) is performed from the old generation snapshot volume and snapshot session. can be taken over.

In FIG. 3C, the master node M reads backup data using, for example, a volume (PV), a volume (P-Snap), and a volume (S-Snap). Specifically, for example, the master node M creates a volume (SV') on the storage device 101.

The volume (SV') is a virtual volume in which backup data stored in the storage device 102 (secondary storage) can be referenced. For example, the master node M receives a request to read data in the volume (SV') from the host device 103 shown in FIG.

Then, in response to the read request, the master node M reads data from one of the volume (PV), volume (P-Snap), and volume (S-Snap), and responds to the host device 103. This allows the user to access the volume (SV') from the host device 103 and refer to the backup data.

In this way, according to the master node M, the backup data stored in the storage device 102 (secondary storage) is transferred from the host device 103 connected to the storage device 101 (primary storage) while ensuring redundancy. It can be made referenceable.

In the example of FIG. 3C, it is assumed that a regular backup is performed once while referring to backup data of the (N-1) generation. In this case, data of the (N+1) generation is remotely copied from the volume (P-Snap') to the volume (SV), and data of the (N) generation is copied to the volume (S-Snap').

Therefore, even if the storage device 101 (primary storage) goes down while referring to the backup data of the (N-1) generation, the data of the (N) generation can be secured. For example, suppose that the storage device 101 (primary storage) goes down while referring to backup data of the (N-1) generation.

In this case, the node 120 (see FIG. 1) of the storage device 102 determines the volume (S-Snap') as the restore source volume. After the primary storage is restored, the node 120 of the storage device 102 transfers the data of the restore source volume to the primary storage. This makes it possible to restore (N) generation data.

(Memory contents of copy session table 400)
Next, the storage contents of the copy session table 400 that each storage device 101, 102 has will be explained. The copy session table 400 is stored, for example, in the memory 122 or disk 130 of the node 120 in each storage device 101, 102.

In the following description, the copy session table 400 possessed by the storage apparatus 101 will be referred to as "copy session table 400(P)," and the copy session table 400 possessed by the storage apparatus 102 will be referred to as "copy session table 400(S)." There are cases.

First, the storage contents of the copy session table 400(P) included in the storage device 101 will be explained.

FIG. 4A is an explanatory diagram showing an example of the storage contents of the copy session table 400(P). In FIG. 4A, copy session table 400(P) has fields of session ID, copy source ID, copy destination ID, local box ID, remote box ID, remote session ID, copy type, direction, status, and phase. By setting information in each field, copy session information 410-1 to 410-4 is stored as a record.

Here, the session ID is an identifier that identifies a copy session. The copy source ID is the volume ID of the copy source volume. The copy destination ID is the volume ID of the copy destination volume. The local box ID is the box ID of the own device. The remote box ID is the box ID of another device. The remote session ID is a remote copy session ID used by another device.

The copy type indicates the type of copy. “Snapshot” or “RemoteCopy” is set as the copy type. The copy type “Snapshot” indicates a snapshot. The copy type "RemoteCopy" indicates remote copy. The direction is the remote copy direction. The direction "L to R" indicates the direction from the local site (self device) to the remote site (other device). The direction "R to L" indicates the direction from the remote site (other device) to the local site (own device).

The status indicates the state of the copy session. The status is set to one of "Active," "Suspend," and "Error." The status "Active" indicates that the state of the copy session is normal. The status "Suspend" indicates that the copy session is being stopped. The status "Error" indicates that the state of the copy session is abnormal.

The phase indicates copying in progress or copy completion. In the case of a copy session of the copy type "Snapshot", "Copying" is set in the phase. In the case of a copy session of the copy type "RemoteCopy", "Copying" or "Equivalent" is set in the phase. The phase "Copying" indicates that copying is in progress. The phase "Equivalent" indicates that the copy has been completed and is in an equivalent state. Note that the local box ID, remote box ID, and remote session ID are set only in the case of remote copy.

Next, the storage contents of the copy session table 400(S) included in the storage device 102 will be explained.

FIG. 4B is an explanatory diagram showing an example of the storage contents of the copy session table 400(S). In FIG. 4B, the copy session table 400(S) has fields of session ID, copy source ID, copy destination ID, local box ID, remote box ID, remote session ID, copy type, direction, status, and phase. By setting information in each field, copy session information 420-1 to 420-4 is stored as a record.

Note that a detailed description of the copy session table 400(S) will be omitted because it is similar to the copy session table 400(P) shown in FIG. 4A.

(Memorized contents of session relationship table 500)
Next, the stored contents of the session relationship table 500 that each storage device 101, 102 has will be explained. The session relationship table 500 is stored, for example, in the memory 122 or disk 130 of the node 120 in each storage device 101, 102.

In the following description, the session relationship table 500 that the storage device 101 has is referred to as a "session relationship table 500 (P)," and the session relationship table 500 that the storage device 102 has is referred to as a "session relationship table 500 (S)." ” may be written.

First, the stored contents of the session relationship table 500(P) included in the storage device 101 will be explained.

FIG. 5A is an explanatory diagram showing an example of the stored contents of the session relationship table 500(P). In FIG. 5A, a session relationship table 500(P) stores the relationship between copy sessions created between the storage apparatuses 101 and 102.

The session relationship table 500 (P) includes local snapshot session ID, local REC session ID, remote REC session ID, local snapshot session ID (#), local REC session ID (#), and remote REC session ID. session ID (#), local volume ID, local snap volume ID, local snap volume ID (#), remote volume ID, remote snap volume ID, remote snap volume ID (#), and primary flag. , the local box ID and the remote box ID are stored in association with each other.

The local snapshot session ID is the session ID of a copy session of the copy type "Snapshot" at the local site (within the own device). The local REC session ID is the session ID of a copy session of the copy type "RemoteCopy" at the local site (within the own device).

The remote REC session ID is the session ID of a copy session of the copy type "RemoteCopy" at the remote site (inside another device). The local snapshot session ID (#) is the session ID of a copy session of the copy type "Snapshot" at the local site (within the own device) that is created when referencing backup data.

The local REC session ID (#) is the session ID of a copy session of the copy type "RemoteCopy" at the local site (within the own device) that is created when referencing backup data. The remote REC session ID (#) is the session ID of a copy session of copy type "RemoteCopy" at a remote site (in another device) that is created when referencing backup data.

The local volume ID is the volume ID of the copy source volume at the local site (within the own device). The local snap volume ID is the volume ID of a volume at the local site (within the own device) that stores a snapshot of the copy source volume. The local snap volume ID (#) is the volume ID of the volume that stores a snapshot of the copy source volume, which is created at the local site (within the own device) when referencing backup data.

The remote volume ID is the volume ID of a copy destination volume located at a remote site (in another device). The remote snap volume ID is the volume ID of a volume located at a remote site (in another device) that stores a snapshot of a copy destination volume. The remote snap volume ID (#) is the volume ID of a volume that is created at a remote site (in another device) when referencing backup data and stores a snapshot of a copy destination volume.

The primary flag is a flag indicating whether or not the own device is a copy source for remote copying. The primary flag "TRUE" indicates that the own device is the copy source. The primary flag "FALSE" indicates that the own device is the copy destination. The local box ID is an identifier that identifies the own device. The remote box ID is an identifier that identifies another device.

Next, the stored contents of the session relationship table 500(S) included in the storage device 102 will be explained.

FIG. 5B is an explanatory diagram showing an example of the stored contents of the session relationship table 500(S). In FIG. 5B, a session relationship table 500(S) stores the relationship between copy sessions created between the storage apparatuses 101 and 102.

Note that a detailed description of the session relationship table 500(S) will be omitted because it is similar to the session relationship table 500(P) shown in FIG. 5A.

(Functional configuration example of master node M)
FIG. 6 is a block diagram showing an example of the functional configuration of the master node M. In FIG. 6, master node M includes a reception unit 601, a backup control unit 602, and a copy control unit 603. Specifically, for example, the reception unit 601 to the copy control unit 603 cause the CPU 121 to execute a program stored in the memory 122 of the master node M (node 120) shown in FIG. F123 realizes this function. The processing results of each functional unit are stored in a storage device such as the memory 122 or the disk 130, for example.

The receiving unit 601 receives backup instructions for the primary volume. The backup instruction is an instruction to back up the data of the primary volume to the secondary volume. The primary volume is, for example, the volume (PV) of the storage device 101 shown in FIG. 2. Further, the secondary volume is, for example, the volume (SV) of the storage device 102 shown in FIG. 2.

The backup instruction includes, for example, the box ID of the primary storage, the volume ID of the primary volume, the box ID of the secondary storage, and the volume ID of the secondary volume. Specifically, for example, the receiving unit 601 receives a backup instruction for the primary volume from the host device 103 shown in FIG.

In the following explanation, a "volume (PV) of the storage device 101" is used as a primary volume, and a "volume (SV) of the storage device 102" is used as an example of a secondary volume. Further, in the initial state, it is assumed that the initial copy from the volume (PV) to the volume (SV) has been completed.

When the backup control unit 602 receives a backup instruction for a volume (PV), it creates a volume (S-Snap) in the storage device 102 (secondary storage). The backup control unit 602 also creates a volume (P-Snap) in the storage device 101 (primary storage). Then, the backup control unit 602 starts remote copying from the volume (P-Snap) to the volume (SV).

Here, the volume (P-Snap) is the first volume in which a snapshot of the volume (PV), which is the primary volume, is created. Further, the volume (S-Snap) is a second volume in which a snapshot of the volume (SV), which is a secondary volume, is created.

Specifically, for example, the backup control unit 602 sends a volume (S-Snap) creation instruction to the storage device 102, which is secondary storage. When the storage device 102 receives the volume (S-Snap) creation instruction, it creates the volume (S-Snap) within its own device.

Then, the storage device 102 creates a snapshot session from the volume (SV) to the volume (S-Snap). Furthermore, the storage device 102 notifies the storage device 101 of the volume ID of the volume (S-Snap) and the session ID of the snapshot session.

The backup control unit 602 also creates a volume (P-Snap) within its own device, and creates a snapshot from the volume (PV) to the volume (P-Snap). Next, the backup control unit 602 creates a remote copy session from the volume (P-Snap) to the volume (SV).

Then, the backup control unit 602 performs backup processing of the volume (PV) using the snapshot (PV/P-Snap), remote copy (REC), and snapshot (SV/S-Snap). Start.

Remote copying (REC) is performed periodically, for example, at predetermined time intervals (several hours, one day, etc.). Specifically, for example, when the remote copy (REC) start timing arrives, the backup control unit 602 calculates the difference between the volume (P-Snap) and the volume (SV) and copies the difference data. Start.

Thereby, it is possible to back up the data of the volume (PV) while suppressing the influence on the I/O performance of the volume (PV). Furthermore, in consideration of communication failures during remote copying, data in the volume (SV) can be backed up on the secondary storage side as well.

Note that when a snapshot session from a volume (PV) to a volume (P-Snap) is created in the storage device 101, for example, copy session information 410-1 is stored in the copy session table 400(P). Ru. Furthermore, when a snapshot is created from a volume (SV) to a volume (S-Snap) in the storage device 102, copy session information 420-2 is stored in the copy session table 400(S), for example. .

Furthermore, when a remote copy session from a volume (P-Snap) to a volume (SV) is created in the storage apparatus 101, copy session information 410-2 is stored in the copy session table 400(P). Furthermore, in the storage device 102, copy session information 420-1 is stored in the copy session table 400(S).

Additionally, when a remote copy session from a volume (P-Snap) to a volume (SV) is created, session relationship tables 500 (P) and 500 (S) are created in each storage device 101 and 102, respectively. be done. Information set in various tables is obtained, for example, by communication between the storage devices 101 and 102.

Note that when the copying of the differential data from the volume (P-Snap) to the volume (SV) is completed, "Equivalent" is set in the phase of the copy session information 410-2 in the copy session table 400 (P). . Furthermore, “Equivalent” is set in the phase of the copy session information 420-1 in the copy session table 400(S).

Further, the receiving unit 601 receives a request to refer to backup data. Here, the backup data reference request is a request to reference backup data stored in the storage device 102 (secondary storage).

The backup data reference request includes, for example, the box ID of the primary storage, the volume ID of the primary volume, the box ID of the secondary storage, and the volume ID of the secondary volume. Specifically, for example, the accepting unit 601 accepts a backup data reference request from the host device 103.

Upon receiving a backup data reference request, the copy control unit 603 creates a volume (P-Snap') in the storage device 101 (primary storage). The copy control unit 603 also creates a volume (S-Snap') in the storage device 102 (secondary storage).

Here, the volume (P-Snap') is a third volume in which a snapshot of the volume (PV), which is the primary volume, is created. Further, the volume (S-Snap') is a fourth volume in which a snapshot of the volume (SV), which is a secondary volume, is created.

Specifically, for example, the copy control unit 603 creates a volume (P-Snap') within its own device, and creates a snapshot from the volume (PV) to the volume (P-Snap'). The copy control unit 603 also sends a volume (S-Snap') creation instruction to the storage device 102, which is secondary storage.

When the storage device 102 receives the volume (S-Snap') creation instruction, it creates the volume (S-Snap') within its own device. The storage device 102 also creates a snapshot session from the volume (SV) to the volume (S-Snap'). Furthermore, the storage device 102 notifies the storage device 101 of the volume ID of the volume (S-Snap') and the session ID of the snapshot session.

Next, the copy control unit 603 creates a remote copy session from the volume (P-Snap') to the volume (SV).

Note that when a snapshot session from a volume (PV) to a volume (P-Snap') is created in the storage device 101, for example, copy session information 410-3 is stored in the copy session table 400 (P). be done. Furthermore, when a snapshot is created from a volume (SV) to a volume (S-Snap') in the storage device 102, for example, copy session information 420-4 is stored in the copy session table 400(S). Ru.

Furthermore, when a remote copy session from a volume (P-Snap') to a volume (SV) is created in the storage device 101, copy session information 410-4 is stored in the copy session table 400 (P). . Furthermore, in the storage device 102, copy session information 420-3 is stored in the copy session table 400(S).

Furthermore, when a remote copy session from a volume (P-Snap') to a volume (SV) is created, session relationship tables 500 (P) and 500 (S) are created in each storage device 101 and 102, respectively. Updated. Information set in various tables is obtained, for example, by communication between the storage devices 101 and 102.

Note that when the copying of differential data from the volume (P-Snap') to the volume (SV) is completed, "Equivalent" is set in the phase of the copy session information 410-4 in the copy session table 400 (P). Ru. Furthermore, “Equivalent” is set in the phase of the copy session information 420-3 in the copy session table 400(S).

Next, the copy control unit 603 backs up the volume (PV) using snapshot (PV/P-Snap), remote copy (REC), and snapshot (SV/S-Snap). Stop processing.

Specifically, for example, the copy control unit 603 stops (suspends) remote copy (REC). The copy control unit 603 also stops snapshots (PV/P-Snap). The copy control unit 603 also sends a snapshot (SV/S-Snap) stop instruction to the storage device 102. When the node 120 of the storage device 102 receives the stop instruction from the master node M, it stops the snapshot (SV/S-Snap).

Next, the copy control unit 603 uses the snapshot (PV/P-Snap'), remote copy (REC'), and snapshot (SV/S-Snap') to ) starts the backup process.

Specifically, for example, the copy control unit 603 starts a snapshot (PV/P-Snap'). Additionally, the copy control unit 603 starts remote copying (REC'). The master node M also sends a snapshot (SV/S-Snap') start instruction to the storage device 102. When the node 120 of the storage device 102 receives the start instruction from the master node M, it starts snapshotting (SV/S-Snap').

As a result, a new generation snapshot volume and a snapshot session can be created in both the storage devices 101 and 102, and backup processing of the volume (PV) can be taken over.

The copy control unit 603 reads backup data using a volume (PV), a volume (P-Snap), and a volume (S-Snap). Specifically, for example, the copy control unit 603 creates a volume (SV') on the storage device 101. The volume (SV') is a virtual volume created to refer to backup data.

The accepting unit 601 accepts a request to read any of the backup data. Specifically, for example, the receiving unit 601 receives a request from the host device 103 to read data in the volume (SV'). In the following description, the data requested to be read may be referred to as "target data."

The read request includes, for example, a logical address that specifies a logical block within the volume (SV'). A logical block is a management unit area defined by a predetermined capacity. The logical address is specified by, for example, an LBA (Logical Block Address). For example, 1 LBA corresponds to a storage area of 512 B (Bytes).

When the copy control unit 603 receives a read request, it determines whether the target data exists in the volume (S-Snap) based on difference information indicating the difference between the volume (SV) and the volume (S-Snap). to judge. The difference information is, for example, a difference bitmap indicating the presence or absence of a difference in a predetermined block unit. The predetermined block is, for example, 16LBA.

Note that the copy control unit 603 obtains difference information indicating the difference between the volume (SV) and the volume (S-Snap) from the storage device 102 and stores it in the memory 122 of its own node. This makes it possible to refer to the difference information stored in the memory 122 and determine whether or not the volume (S-Snap) contains target data. However, the copy control unit 603 may inquire of the storage device 102 whether or not there is target data in the volume (S-Snap).

Here, if it is determined that the target data exists in the volume (S-Snap), the copy control unit 603 reads the target data from the volume (S-Snap) in the storage device 102. On the other hand, if it is determined that there is no target data in the volume (S-Snap), the copy control unit 603 reads the target data from the volume (PV) or the volume (P-Snap). The copy control unit 603 then responds with the read target data to the read request source. The read request source is, for example, the host device 103.

Note that an example of the operation when referring to backup data in the storage system 100 will be described later using FIG. 7. Further, when reading the target data, the copy control unit 603 may read the target data from, for example, a volume (SV) or a volume (S-Snap').

The copy control unit 603 stops the remote copy (REC') when the reference to the backup data is finished. The copy control unit 603 also performs volume (PV) backup processing using snapshots (PV/P-Snap), remote copies (REC), and snapshots (SV/S-Snap). resume.

Specifically, for example, when the copy control unit 603 receives a backup data reference termination request from the host device 103, it stops remote copying (REC'). Next, the copy control unit 603 restarts the snapshot (PV/P-Snap) and the snapshot (SV/S-Snap). Further, the copy control unit 603 restarts remote copy (REC). This allows the volume (PV) backup process to be restarted. The copy control unit 603 then deletes the volume (SV').

The copy control unit 603 also copies new data in the volume (P-Snap') to the volume (P-Snap), and copies new data in the volume (S-Snap') to the volume (S-Snap). do. Then, the copy control unit 603 deletes the volume (P-Snap') and the volume (S-Snap').

Specifically, for example, the copy control unit 603 transfers new data in the volume (P-Snap') to the volume (P-Snap') based on the difference information between the volume (PV) and the volume (P-Snap'). -Snap). The copy control unit 603 also copies new data in the volume (S-Snap') to the volume (S-Snap) based on the difference information between the volume (SV) and the volume (S-Snap'). do. Difference information indicating the difference between the volume (SV) and the volume (S-Snap') is acquired from the storage device 102, for example.

Thereby, in response to the end of the user's reference to the backup data, the state of the copy session in the storage system 100 can be returned to the state before the reference to the backup data.

When the volume (P-Snap') and volume (S-Snap') are deleted, the copy session information 410-3 and 410-4 in the copy session table 400(P) is deleted in the storage device 101, for example. Ru. Furthermore, in the storage device 102, for example, the copy session information 420-3 and 420-4 in the copy session table 400(S) is deleted. Furthermore, session relationship tables 500(P) and 500(S) are updated in each storage device 101 and 102, respectively.

Note that an example of the operation at the end of referencing backup data in the storage system 100 will be described later using FIGS. 8A, 8B, and 8C.

(Example of operation when referring to backup data)
Next, an example of the operation when referring to backup data in the storage system 100 will be described using FIG. 7.

FIG. 7 is an explanatory diagram showing an example of the operation when referring to backup data. In FIG. 7, when the copy control unit 603 receives a read request for target data in the volume (S-V') from the host device 103, the copy control unit 603 stores the target data in the volume (S-Snap) based on the difference information 710. Determine whether or not there is.

The difference information 710 is a difference bitmap indicating the difference between the volume (SV) and the volume (S-Snap). Specifically, for example, the copy control unit 603 refers to the difference information 710 and determines that the volume (S-Snap) contains the target data if the corresponding block in which the target data is stored has a difference. On the other hand, if the corresponding block has no difference, the copy control unit 603 determines that there is no target data in the volume (S-Snap).

Here, if it is determined that the target data exists in the volume (S-Snap), the copy control unit 603 reads the target data from the volume (S-Snap) in the storage device 102. The copy control unit 603 then transmits the read target data to the host device 103.

On the other hand, if it is determined that there is no target data in the volume (S-Snap), the copy control unit 603 determines whether or not there is target data in the volume (P-Snap) based on the difference information 720. . The difference information 720 is a difference bitmap indicating the difference between the volume (PV) and the volume (P-Snap).

Specifically, for example, the copy control unit 603 refers to the difference information 720 and determines that the volume (P-Snap) contains the target data if the corresponding block in which the target data is stored has a difference. On the other hand, if the corresponding block has no difference, the copy control unit 603 determines that there is no target data in the volume (P-Snap).

Here, if it is determined that the target data exists in the volume (P-Snap), the copy control unit 603 reads the target data from the volume (P-Snap) within the own device. On the other hand, if it is determined that there is no target data in the volume (P-Snap), the copy control unit 603 reads the target data from the volume (PV) within the own device. The copy control unit 603 then transmits the read target data to the host device 103.

This makes it possible to read the backup data and respond. Further, by reading data stored in both the storage devices 101 and 102 from the storage device 101 (primary storage), it is possible to suppress the transfer cost when reading data.

(Example of operation when reference of backup data is finished)
Next, an example of the operation at the end of referencing backup data in the storage system 100 will be described using FIGS. 8A, 8B, and 8C.

FIG. 8A, FIG. 8B, and FIG. 8C are explanatory diagrams showing an example of the operation at the end of referencing backup data. In FIG. 8A, first, when the copy control unit 603 receives a backup data reference termination request, it stops the remote copy (REC'), performs a snapshot (PV/P-Snap), and a snapshot (Snap). - V/S-Snap) and remote copy (REC).

As a result, the copy control unit 603 uses snapshot (PV/P-Snap), snapshot (SV/S-Snap), and remote copy (REC) to back up the volume (PV). Resume processing. The copy control unit 603 then deletes the volume (SV').

In FIG. 8B, the copy control unit 603 then copies the new data in the volume (P-Snap') to the volume (P-Snap) based on the difference information 810. The difference information 810 is a difference bitmap indicating the difference between the volume (PV) and the volume (P-Snap'). Specifically, for example, the copy control unit 603 refers to the difference information 810 and copies the data of the block with the difference (new data) to the volume (P-Snap).

The copy control unit 603 also sends an instruction to copy new data in the volume (S-Snap') to the volume (S-Snap) to the storage device 102. Upon receiving the copy instruction from the master node M, the node 120 of the storage device 102 copies the new data in the volume (S-Snap') to the volume (S-Snap) based on the difference information 820.

The difference information 820 is a difference bitmap indicating the difference between the volume (SV) and the volume (S-Snap'). Specifically, for example, the node 120 of the storage device 102 refers to the difference information 820 and copies the data of the block with the difference (new data) to the volume (S-Snap).

In FIG. 8C, the copy control unit 603 deletes the volume (P-Snap'). The copy control unit 603 also deletes the volume (S-Snap'). Specifically, for example, the copy control unit 603 transmits an instruction to delete the volume (S-Snap') to the storage device 102. Upon receiving the deletion instruction from the master node M, the node 120 of the storage device 102 deletes the volume (S-Snap').

Thereby, in response to the end of the user's reference to the backup data, the state of the copy session in the storage system 100 can be returned to the state before the reference to the backup data. In the example of FIG. 8C, data of the (N+1) generation is stored in the volume (P-Snap) and volume (SV), and data of the (N) generation is stored in the volume (S-Snap).

(Backup processing procedure for master node M)
Next, a backup processing procedure for the master node M in the storage device 101 will be explained. The backup process of the master node M is executed, for example, in response to a backup instruction for a volume (PV) or at specified time intervals (eg, one hour, one day, etc.). Here, it is assumed that the initial copy from the volume (PV) to the volume (SV) has been completed in the initial state.

FIG. 9 is a flowchart illustrating an example of the backup processing procedure of the master node M. In the flowchart of FIG. 9, first, the master node M determines whether a volume (S-Snap) exists (step S901).

Specifically, for example, the master node M refers to the session relationship table 500(P) and determines that the volume (S-Snap) exists if a volume ID is set in the remote snap volume ID. . On the other hand, if no volume ID is set in the remote snap volume ID, it is determined that the volume (S-Snap) does not exist. Furthermore, the master node M may determine whether a volume (S-Snap) exists by inquiring the storage device 102.

Here, if the volume (S-Snap) exists (step S901: Yes), the master node M moves to step S903. On the other hand, if the volume (S-Snap) does not exist (step S901: No), the master node M transmits a volume (S-Snap) creation instruction to the storage device 102 (step S902).

Note that when the storage device 102 receives a volume (S-Snap) creation instruction from the master node M, it creates the volume (S-Snap). Then, the storage device 102 creates a snapshot session from the volume (SV) to the volume (S-Snap). As a result, the copy session information 420-2 is stored in the copy session table 400(S) in the storage device 102. Furthermore, the storage device 102 notifies the master node M of the volume ID of the volume (S-Snap) and the session ID of the snapshot (SV/S-Snap).

Next, the master node M determines whether a volume (P-Snap) exists within its own device (step S903). Here, if the volume (P-Snap) exists (step S903: Yes), the master node M moves to step S906. On the other hand, if the volume (P-Snap) does not exist (step S903: No), the master node M creates a volume (P-Snap) within its own device (step S904).

Then, the master node M creates a snapshot session from the volume (PV) to the volume (P-Snap) (step S905). As a result, in master node M, copy session information 410-1 is stored in copy session table 400(P).

Next, the master node M creates a remote copy session from the volume (P-Snap) to the volume (SV) (step S906). As a result, in master node M, copy session information 410-2 is stored in copy session table 400(P). Furthermore, in the storage device 102, copy session information 420-1 is stored in the copy session table 400(S). Furthermore, session relationship tables 500(P) and 500(S) are created in each storage device 101 and 102, respectively.

Then, master node M backs up the volume (PV) using snapshot (PV/P-Snap), snapshot (SV/S-Snap), and remote copy (REC). The process starts (step S907), and the series of processes according to this flowchart ends.

Thereby, it is possible to back up the data of the volume (PV) while suppressing the influence on the I/O performance of the volume (PV). Furthermore, in consideration of communication failures during remote copying, data in volumes (SVs) can be backed up on the remote site side as well.

In addition, in remote copy (REC), the differential data between the volume (P-Snap) and the volume (SV) is copied, and when the differential data copy is completed, " "Equivalent" is set. Furthermore, "Equivalent" is set in the phase of the copy session information 420-1.

(Preparation processing procedure for master node M)
Next, the advance preparation processing procedure of the master node M in the storage device 101 will be explained. The advance preparation process of the master node M is executed as advance preparation, for example, when referring to backup data.

FIG. 10 is a flowchart illustrating an example of the advance preparation processing procedure of the master node M. In the flowchart of FIG. 10, first, the master node M determines whether or not it has received a backup data reference request from the host device 103 (step S1001).

Here, the master node M waits for receiving a backup data reference request (step S1001: No). When the master node M receives the backup data reference request (step S1001: Yes), it waits for the completion of remote copy (REC) from the volume (P-Snap) to the volume (SV) (step S1002).

Next, master node M creates a volume (P-Snap') within its own device (step S1003). Then, the master node M transmits a volume (S-Snap') creation instruction to the storage device 102 (step S1004). Note that when the storage device 102 receives a volume (S-Snap') creation instruction from the master node M, it creates the volume (S-Snap').

Next, the master node M creates a snapshot session from the volume (PV) to the volume (P-Snap') (step S1005). Then, the master node M creates a remote copy session from the volume (P-Snap') to the volume (SV) (step S1006).

Next, the master node M sends an instruction to create a snapshot session from the volume (SV) to the volume (S-Snap') to the storage device 102 (step S1007). Note that when the storage device 102 receives a snapshot session creation instruction from the master node M, it creates a snapshot session from the volume (SV) to the volume (S-Snap').

Then, master node M suspends remote copy (REC) (step S1008). Next, the master node M suspends the snapshot (PV/P-Snap) and the snapshot (SV/S-Snap) (step S1009).

Note that regarding the snapshot (SV/S-Snap), the master node M sends an instruction to stop the snapshot (SV/S-Snap) to the storage device 102. When the node 120 of the storage device 102 receives the stop instruction from the master node M, it stops the snapshot (SV/S-Snap).

Next, master node M uses snapshot (PV/P-Snap'), snapshot (SV/S-Snap'), and remote copy (REC') to V) backup processing is started (step S1010). Then, the master node M creates a volume (SV') on its own device (step S1011), and ends the series of processes according to this flowchart.

As a result, a new generation snapshot volume and a snapshot session can be created in both the storage devices 101 and 102, and backup processing of the volume (PV) can be taken over.

(Procedure for referencing backup data of master node M)
Next, the backup data reference processing procedure of the master node M in the storage device 101 will be explained.

FIG. 11 is a flowchart illustrating an example of the backup data reference processing procedure of the master node M. In the flowchart of FIG. 11, first, the master node M determines whether a request to read data in the volume (SV') has been received from the host device 103 (step S1101).

Here, the master node M waits for receiving a data read request (step S1101: No). When the master node M receives the data read request (step S1101: Yes), the master node M reads the volume (S-Snap) based on the difference information indicating the difference between the volume (SV) and the volume (S-Snap). It is determined whether there is target data in (step S1102).

Here, if the target data is in the volume (S-Snap) (step S1102: Yes), the master node M reads the target data from the volume (S-Snap) (step S1103), and moves to step S1107.

On the other hand, if the volume (S-Snap) does not exist (step S1102: No), the master node M determines the volume (P-Snap) based on the difference information indicating the difference between the volume (PV) and the volume (P-Snap). -Snap) includes target data (step S1104).

Here, if the target data is in the volume (P-Snap) (step S1104: Yes), the master node M reads the target data from the volume (P-Snap) (step S1105), and moves to step S1107.

On the other hand, if the target data is not in the volume (P-Snap) (step S1104: No), the master node M reads the target data from the volume (PV) (step S1106). Then, the master node M transmits the read data to the host device 103 (step S1107), and ends the series of processes according to this flowchart.

This allows the backup data to be read and responded to in response to a read request from the host device 103. Further, by reading data stored in both the storage devices 101 and 102 from the storage device 101 (primary storage), it is possible to suppress the transfer cost when reading data.

(Post-processing procedure of master node M)
Next, the post-processing procedure of the master node M in the storage device 101 will be explained.

FIG. 12 is a flowchart illustrating an example of the post-processing procedure of the master node M. In the flowchart of FIG. 12, first, the master node M determines whether or not it has received a backup data reference termination request from the host device 103 (step S1201).

Here, the master node M waits to receive a request to end the reference of the backup data (step S1201: No). Then, when the master node M receives the request to end the reference of backup data (step S1201: Yes), it suspends the remote copy (REC') (step S1202).

Next, the master node M restarts remote copy (REC) (step S1203), and restarts snapshots (PV/P-Snap) and snapshots (SV/S-Snap) (step S1204). ). Then, master node M performs backup processing of volume (PV) using snapshot (PV/P-Snap), snapshot (SV/S-Snap), and remote copy (REC). It restarts (step S1205).

Next, the master node M deletes the volume (SV') (step S1206). Then, the master node M transfers the new data in the volume (P-Snap') to the volume (P-Snap') based on the difference information indicating the difference between the volume (PV) and the volume (P-Snap'). (Step S1207).

Next, the master node M transmits an instruction to copy the new data in the volume (S-Snap') to the volume (S-Snap) to the storage device 102 (step S1208). Upon receiving the copy instruction from the master node M, the node 120 of the storage device 102 copies the volume (S-Snap') based on the difference information indicating the difference between the volume (SV) and the volume (S-Snap'). ) is copied to the volume (S-Snap).

Next, master node M deletes the volume (P-Snap') (step S1209). Then, the master node M transmits an instruction to delete the volume (S-Snap') to the storage device 102 (step S1210), and ends the series of processes according to this flowchart. Upon receiving the deletion instruction from the master node M, the node 120 of the storage device 102 deletes the volume (S-Snap').

Thereby, in response to the end of the user's reference to the backup data, the state of the copy session in the storage system 100 can be returned to the state before the reference to the backup data.

Note that when a volume (P-Snap) or volume (S-Snap) is referenced while executing a series of processes according to this flowchart, new data is stored in the volume (P-Snap') or volume (S-Snap'). may exist. In this case, the master node M responds by reading new data from the volume (P-Snap') or volume (S-Snap').

As explained above, according to the master node M (storage control device) according to the embodiment, a snapshot of a volume (PV) is created in response to a request to refer to backup data. (P-Snap') and a volume (S-Snap') in which a snapshot of the volume (SV) is created. Also, according to master node M, backup of volume (PV) using snapshot (PV/P-Snap), remote copy (REC), and snapshot (SV/S-Snap) Processing can be stopped. According to the master node M, the volume (P-V/S-Snap') is ) backup process can be started.

Thereby, when referencing backup data, a new generation snapshot volume and a snapshot session can be created in both the storage devices 101 and 102, and backup processing of the volume (PV) can be taken over. Therefore, the backup data stored in the storage device 102 (secondary storage) can be referenced while ensuring redundancy.

Further, according to the master node M, backup data can be read using a volume (PV), a volume (P-Snap), and a volume (S-Snap). For example, when the master node M receives a data read request from the host device 103, the master node M reads the volume (S-Snap) based on the difference information indicating the difference between the volume (SV) and the volume (S-Snap). Determine whether or not there is target data. Here, if it is determined that the target data exists in the volume (S-Snap), the master node M reads the target data from the volume (S-Snap). On the other hand, if it is determined that there is no target data in the volume (S-Snap), the master node M reads the target data from the volume (PV) or the volume (P-Snap). The master node M then transmits the read target data to the host device 103.

Thereby, backup data can be read and responded to in response to a read request from the host device 103 connected to the storage device 101 (primary storage). Further, by reading data stored in both the storage devices 101 and 102 from the storage device 101, it is possible to reduce the transfer cost when reading the data.

Also, according to master node M, when reference of backup data is finished, remote copy (REC') is stopped and snapshot (PV/P-Snap), remote copy (REC) and snapshot ( Backup processing of the volume (PV) using SV/S-Snap can be restarted. Also, according to the master node M, new data in the volume (P-Snap') is transferred to the volume (P-Snap) based on the difference information between the volume (PV) and the volume (P-Snap'). New data in the volume (S-Snap') can be copied to the volume (S-Snap) based on the difference information between the volume (SV) and the volume (S-Snap'). According to the master node M, the volume (P-Snap') and the volume (S-Snap') can be deleted.

Thereby, in response to the end of the user's reference to the backup data, the state of the copy session in the storage system 100 can be returned to the state before the reference to the backup data.

For these reasons, according to the master node M (storage control device) and storage system 100 according to the embodiment, from the host device 103 connected to the storage device 101 (primary storage) to the storage device 102 (secondary storage) Stored backup data can be referenced while ensuring redundancy.

Note that the storage control method described in this embodiment can be realized by executing a program prepared in advance on a computer such as a storage control device. This storage control program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD (Compact Disc)-ROM, a DVD (Digital Versatile Disk), and a USB (Universal Serial Bus) memory. It is executed by reading from. Further, this storage control program may be distributed via a network such as the Internet.

Furthermore, the storage control device (master node M) described in this embodiment can also be realized by a specific application IC such as a standard cell or a structured ASIC (Application Specific Integrated Circuit), or a PLD (Programmable Logic Device) such as an FPGA. be able to.

Regarding the embodiments described above, the following additional notes are further disclosed.

(Additional Note 1) A first storage device having a primary volume and a first volume in which a snapshot of the primary volume is created, a secondary volume to which data of the snapshot of the primary volume is remotely copied, and a first volume in which a snapshot of the primary volume is created; A storage control device of a storage system including a second storage device having a second volume on which a snapshot is created,
In response to receiving a backup data reference request, creating a third volume in which a snapshot of the primary volume is created and a fourth volume in which a snapshot of the secondary volume is created;
Backup processing of the primary volume using a snapshot from the primary volume to the first volume, a remote copy from the first volume to the secondary volume, and a snapshot from the secondary volume to the second volume. stop and
Backup processing of the primary volume using a snapshot from the primary volume to the third volume, a remote copy from the third volume to the secondary volume, and a snapshot from the secondary volume to the fourth volume. start,
A storage control device characterized by having a control section.

(Additional Note 2) The control section is
The storage control device according to appendix 1, wherein the backup data is read using the primary volume, the first volume, and the second volume.

(Additional Note 3) The control section is
When a read request for any of the backup data is received, determining whether the data is in the second volume based on difference information between the secondary volume and the second volume;
If it is determined that the data exists in the second volume, the data is read from the second volume, and if it is determined that the data does not exist in the second volume, the data is read from the primary volume or the first volume. read data,
The storage control device according to appendix 2, characterized in that:

(Additional Note 4) The control section is
When the reference to the backup data is finished, the remote copy from the third volume to the secondary volume is stopped, and the snapshot is taken from the primary volume to the first volume, and from the first volume to the secondary volume. restarting backup processing of the primary volume using remote copy and snapshot from the secondary volume to the second volume;
Copying new data in the third volume to the first volume based on differential information between the primary volume and the third volume;
Copying new data in the fourth volume to the second volume based on differential information between the secondary volume and the fourth volume;
deleting the third volume and the fourth volume;
The storage control device according to any one of Supplementary Notes 1 to 3, characterized in that:

(Additional Note 5) The storage control device is provided in the first storage device,
The control unit according to any one of appendices 1 to 4, wherein the control unit receives a read request for any of the backup data from a host device connected to the first storage device. Storage controller.

(Additional Note 6) The third volume is created on the first storage device,
the fourth volume is created on the second storage device;
6. The storage control device according to any one of appendices 1 to 5, characterized in that:

(Additional Note 7) A first storage device having a primary volume and a first volume in which a snapshot of the primary volume is created, a secondary volume to which data of the snapshot of the primary volume is remotely copied, and a first volume in which a snapshot of the primary volume is created; a second storage device having a second volume on which the snapshot is to be created;
In response to receiving a backup data reference request, creating a third volume in which a snapshot of the primary volume is created and a fourth volume in which a snapshot of the secondary volume is created;
Backup processing of the primary volume using a snapshot from the primary volume to the first volume, a remote copy from the first volume to the secondary volume, and a snapshot from the secondary volume to the second volume. stop and
Backup processing of the primary volume using a snapshot from the primary volume to the third volume, a remote copy from the third volume to the secondary volume, and a snapshot from the secondary volume to the fourth volume. start,
A storage control program that executes processing.

(Additional Note 8) A first storage device having a primary volume and a first volume in which a snapshot of the primary volume is created;
a second storage device having a secondary volume to which snapshot data of the primary volume is remotely copied; and a second volume to which the snapshot of the secondary volume is created;
In response to receiving a backup data reference request, a third volume in which a snapshot of the primary volume is created and a fourth volume in which a snapshot of the secondary volume is created, and stopping backup processing of the primary volume using a snapshot to the first volume, a remote copy from the first volume to the secondary volume, and a snapshot from the secondary volume to the second volume; Backup processing of the primary volume using a snapshot from the primary volume to the third volume, a remote copy from the third volume to the secondary volume, and a snapshot from the secondary volume to the fourth volume. a storage controller that initiates the
A storage system comprising:

100 storage system 101,102 storage device 103 host device 110 network 120 node 121 CPU
122 Memory 123 Communication I/F
124 Bus 130 Disk 400, 400 (P), 400 (S) Copy session table 500, 500 (P), 500 (S) Session relationship table 601 Reception section 602 Backup control section 603 Copy control section 710, 720, 810, 820 Difference information M Master node

Claims (4)

A first storage device having a primary volume and a first volume in which a snapshot of the primary volume is created, a secondary volume to which data of the snapshot of the primary volume is remotely copied, and a snapshot of the secondary volume is created. A storage control device for a storage system, comprising: a second storage device having a second volume;
In response to receiving a backup data reference request, creating a third volume in which a snapshot of the primary volume is created and a fourth volume in which a snapshot of the secondary volume is created;
Backup processing of the primary volume using a snapshot from the primary volume to the first volume, a remote copy from the first volume to the secondary volume, and a snapshot from the secondary volume to the second volume. stop and
Backup processing of the primary volume using a snapshot from the primary volume to the third volume, a remote copy from the third volume to the secondary volume, and a snapshot from the secondary volume to the fourth volume. start ,
When a read request for any of the backup data is received, determining whether the data is in the second volume based on difference information between the secondary volume and the second volume;
If it is determined that the data exists in the second volume, the data is read from the second volume, and if it is determined that the data does not exist in the second volume, the data is read from the primary volume or the first volume. read the data,
responding to the read request source with the read data;
A storage control device characterized by having a control section. The control unit includes:
When the reference to the backup data is finished, the remote copy from the third volume to the secondary volume is stopped, and the snapshot is taken from the primary volume to the first volume, and from the first volume to the secondary volume. restarting backup processing of the primary volume using remote copy and snapshot from the secondary volume to the second volume;
Copying new data in the third volume to the first volume based on differential information between the primary volume and the third volume;
Copying new data in the fourth volume to the second volume based on differential information between the secondary volume and the fourth volume;
deleting the third volume and the fourth volume;
The storage control device according to claim 1, characterized in that: A first storage device having a primary volume and a first volume in which a snapshot of the primary volume is created, a secondary volume to which data of the snapshot of the primary volume is remotely copied, and a snapshot of the secondary volume is created. a second storage device having a second volume;
In response to receiving a backup data reference request, creating a third volume in which a snapshot of the primary volume is created and a fourth volume in which a snapshot of the secondary volume is created;
Backup processing of the primary volume using a snapshot from the primary volume to the first volume, a remote copy from the first volume to the secondary volume, and a snapshot from the secondary volume to the second volume. stop and
Backup processing of the primary volume using a snapshot from the primary volume to the third volume, a remote copy from the third volume to the secondary volume, and a snapshot from the secondary volume to the fourth volume. start,
When a read request for any of the backup data is received, determining whether the data is in the second volume based on difference information between the secondary volume and the second volume;
If it is determined that the data exists in the second volume, the data is read from the second volume, and if it is determined that the data does not exist in the second volume, the data is read from the primary volume or the first volume. read the data,
responding to the read request source with the read data;
A storage control program that executes processing. a first storage device having a primary volume and a first volume in which a snapshot of the primary volume is created;
a second storage device having a secondary volume to which snapshot data of the primary volume is remotely copied; and a second volume to which the snapshot of the secondary volume is created;
In response to receiving a backup data reference request, a third volume in which a snapshot of the primary volume is created and a fourth volume in which a snapshot of the secondary volume is created, and stopping backup processing of the primary volume using a snapshot to the first volume, a remote copy from the first volume to the secondary volume, and a snapshot from the secondary volume to the second volume; Backup processing of the primary volume using a snapshot from the primary volume to the third volume, a remote copy from the third volume to the secondary volume, and a snapshot from the secondary volume to the fourth volume. and when a read request for any of the backup data is received, it is determined whether the data is in the second volume based on the difference information between the secondary volume and the second volume. If it is determined that the data exists in the second volume, the data is read from the second volume, and if it is determined that the data does not exist in the second volume, the data is read from the primary volume or the first volume. a storage control device that reads the data from and responds to a read request source with the read data;
A storage system comprising:

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