Data migration using a consistency group

Abstract

The present disclosure relates to data migration using a consistency group. Example embodiments relate to computer data storage. In some examples, a controller establishes a migration link between a first storage device and a second storage device and creates a consistency group that includes a replica volume and a control volume stored on the first storage device. The controller initiates a data copy from the replica volume to a proxy volume on the second storage device based on the consistency group. In response to completion of the data copy from the replica volume to the proxy volume, the controller initiates replication of the proxy volume to the second storage device. Further, in response to completion of the replication of the proxy volume, the controller transfers a copy of the control volume to the second storage device, wherein the transfer of the copy of the control volume causes completion of migration of the consistency group.

Description

Technical Field

[0001] This disclosure generally relates to data migration. Background Technology

[0002] Computing devices may include components such as processors, memory, cache systems, and storage devices. Storage devices may include hard disk drives that use magnetic media to store and retrieve blocks of data. Some storage systems can transfer data between different locations or devices. For example, some systems can transfer and store copies of important data for archiving and recovery purposes. Summary of the Invention

[0003] According to one aspect of this disclosure, a management system is provided, the management system comprising: a controller; and a machine-readable storage device storing instructions executable by a processor to perform the following operations: establishing a migration link between a first storage device and a second storage device, wherein the first storage device stores a set of replicated volumes replicated on the first replication device; creating a consistency group comprising the set of replicated volumes and a control volume stored on the first storage device, wherein the consistency group is a set of data elements migrated together; initiating a data copy from the set of replicated volumes to a set of proxy volumes on the second storage device based on the consistency group, wherein the proxy volumes forward input / output I / O transactions to the set of replicated volumes; initiating a copy of the set of proxy volumes from the second storage device to the second replication device in response to the completion of the data copy from the set of replicated volumes to the set of proxy volumes; and transferring a copy of the control volume from the first storage device to the second storage device in response to the completion of the copy of the set of proxy volumes from the second storage device to the second replication device, wherein transferring the copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device.

[0004] According to another aspect of this disclosure, a method for data migration is provided, the method comprising: establishing a migration link between a first storage device and a second storage device by a controller, wherein the first storage device stores a set of replicated volumes replicated on the first replication device; creating a consistency group by the controller including the set of replicated volumes and a control volume stored on the first storage device, wherein the consistency group is a set of data elements migrated together; initiating a data copy from the set of replicated volumes to a set of proxy volumes on the second storage device based on the consistency group, wherein the proxy volumes forward input / output I / O transactions to the set of replicated volumes; in response to the completion of the data copy from the set of replicated volumes to the set of proxy volumes, initiating a copy of the set of proxy volumes from the second storage device to the second replication device by the controller; and in response to the completion of the copy of the set of proxy volumes from the second storage device to the second replication device, transferring a copy of the control volume from the first storage device to the second storage device by the controller, wherein transferring a copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device.

[0005] According to another aspect of this disclosure, a non-transitory machine-readable medium storing instructions that, when executed, cause a controller to perform the following operations: establish a migration link between a first storage device and a second storage device, wherein the first storage device stores a set of replicated volumes replicated on the first replication device; create a consistency group comprising the set of replicated volumes and a control volume stored on the first storage device, wherein the consistency group is a set of data elements migrated together; based on the consistency group, initiate a data copy from the set of replicated volumes to a set of proxy volumes on the second storage device, wherein the proxy volumes forward input / output I / O transactions to the set of replicated volumes; in response to the completion of the data copy from the set of replicated volumes to the set of proxy volumes, initiate a copy of the set of proxy volumes from the second storage device to the second replication device; and in response to the completion of the copy of the set of proxy volumes from the second storage device to the second replication device, transfer a copy of the control volume from the first storage device to the second storage device, wherein transferring a copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device. Attached Figure Description

[0006] Some implementation methods are described with reference to the following figures.

[0007] Figure 1 This is a schematic diagram of an example system based on some implementation methods.

[0008] Figure 2This is a diagram illustrating an example process based on some implementation methods.

[0009] Figures 3A to 3F These are illustrations of example operations based on some implementation methods.

[0010] Figure 4 This is a schematic diagram of an example management system based on some implementation methods.

[0011] Figure 5 This is a diagram illustrating an example process based on some implementation methods.

[0012] Figure 6 This is a diagram of an example machine-readable medium storing instructions according to some implementation methods.

[0013] Throughout the accompanying drawings, the same reference numerals denote similar but not necessarily identical elements. The drawings are not necessarily drawn to scale, and some parts may be enlarged to illustrate the examples more clearly. Furthermore, the drawings provide examples and / or embodiments consistent with the description; however, the description is not limited to the examples and / or embodiments provided in the drawings. Detailed Implementation

[0014] In this disclosure, unless the context clearly indicates otherwise, the terms “a,” “an,” or “the” are intended to include the plural form as well. Similarly, when used in this disclosure, the terms “includes / including / comprises / comprising” or “have / having” indicate the presence of the stated element but do not preclude the presence or addition of other elements.

[0015] As used herein, a “storage system” may include a storage device or an array of storage devices. A storage system may also include multiple storage controllers that manage access to the storage device(s). A “data unit” may refer to any portion of data in a storage system that can be individually identified. In some cases, a data unit may refer to a block, a collection of blocks, or any other portion of data. In some examples, a storage system may store data units in persistent storage devices. Persistent storage devices may be implemented using one or more persistent (e.g., non-volatile) storage devices (such as multiple disk-based storage devices (e.g., multiple hard disk drives (HDDs)), multiple solid-state drives (SSDs) (such as multiple flash storage devices), etc., or combinations thereof). As used herein, a “controller” may refer to hardware processing circuitry, which may include any or a combination of a microprocessor, a core of a multi-core microprocessor, a microcontroller, a programmable integrated circuit, a programmable gate array, a digital signal processor, or other hardware processing circuitry. Alternatively, a “controller” may refer to a combination of hardware processing circuitry and machine-readable instructions (software and / or firmware) executable on the hardware processing circuitry.

[0016] In some examples, a collection of input data (e.g., a real-time data value stream) can be persistently stored on a storage system. The storage system may include two (or more) storage devices that store replicated copies of the data. For example, the storage system may include a first storage array that stores copies of the data collection, and may also include a second storage array that stores replicated copies of the data collection stored on the first storage array. In this way, valuable or business-critical data (e.g., banking transaction data) can be protected from loss in the event of a failure of a single device or array.

[0017] In some examples, an existing storage system may be replaced with a different storage system (e.g., a newer storage system with improved storage capacity, data throughput, data security, etc.). This replacement process may include migrating data stored on the existing storage system to the different storage system. However, the two storage systems may not be able to perform the data migration without interrupting normal storage functionality. For example, the two storage systems may be provided by different vendors (or may use different product lines or equipment from the same vendor) and may not have compatible functionalities to perform the data migration while simultaneously receiving new input data and maintaining a complete replication of the stored data. Therefore, in such an example, performing the data migration may involve interrupting the reception of new input data and / or failing to maintain a complete replication of the stored data throughout the entire data migration period. Thus, in such an example, performing the data migration may negatively impact the reliability and performance of one or both storage systems.

[0018] According to some embodiments of this disclosure, a controller can perform a migration process to replace an existing ("source") storage system with a different ("destination") storage system. The source and destination storage systems may each include a primary storage device and a secondary replication device. In some embodiments, the migration process may include defining a consistency group that includes all replicated volumes on the source storage device (i.e., volumes replicated to the source replication device) and also includes a virtual control volume that does not contain data content. The migration process may also include transferring replicated volumes from the source storage device to the destination storage device and initiating data replication from the destination storage device to the destination replication device. Further, after data replication is complete, the migration process may include transferring the control volume from the source storage device to the destination storage device, thereby completing the migration of the consistency group. In this way, the migration process can be completed while maintaining data storage and replication. References below... Figures 1 to 6 Further discussion of the various aspects of the disclosed migration process.

[0019] Figure 1 - Example System

[0020] Figure 1 An example system 100 according to some implementations is illustrated. System 100 may include a client device 105, a source system 112, and a destination system 122. The source system 112 may include a source storage device 110 and a source replication device 115. In some implementations, the source storage device 110 may receive data from the client device 105 and may persistently store the received data. Further, some or all of the data stored on the source storage device 110 may be copied or "replicated" to be persistently stored on the source replication device 115. For example, the source storage device 110 may store the data in a set of volumes (e.g., logical storage units) that are automatically replicated to the source replication device 115 (also referred to herein as the "replicated volume"). In this way, data received from the client device 105 may be persistently stored in two different storage devices 110, 115, and thus may be protected from loss due to the failure of one of the two storage devices 110, 115.

[0021] In some implementations, source system 112 may be replaced by destination system 122, which includes destination storage device 120 and destination replication device 125. For example, the owner or administrator of system 100 may determine that source system 112 is an older storage system that does not meet a set of requirements (e.g., based on storage capacity, data throughput, data security, etc.), and therefore can replace source system 112 with a newer destination system 122 that meets those requirements. In some examples, source system 112 and destination system 122 may be provided by different vendors, or different product lines or devices from the same vendor may be used.

[0022] In some implementations, the process of replacing source system 112 with destination system 122 (also referred to herein as the "migration process") may include copying data stored on source system 112 to destination system 122. Further, after the migration process is completed, destination storage device 120 may receive input data from client device 105 and may persistently store the received data. Further, data stored on destination storage device 120 may be copied to destination replication device 125.

[0023] In some implementations, some or all of devices 110, 115, 120, and 125 may be implemented using multiple persistent (e.g., non-volatile) storage devices (e.g., multiple disk-based storage devices (e.g., multiple hard disk drives (HDDs), multiple solid-state drives (SSDs) (e.g., multiple flash storage devices), etc.). For example, devices 110, 115, 120, and 125 may be different storage arrays, each including multiple storage components (e.g., HDDs, SSDs, etc.).

[0024] In some implementations, destination storage device 120 may include a controller 130 for managing storage operations. The controller 130 may be implemented via hardware (e.g., electronic circuitry) or a combination of hardware and programming (e.g., including at least one processor and instructions executable by said at least one processor and stored on at least one machine-readable storage medium).

[0025] In some implementations, controller 130 may include functionality for managing the migration process to replace source system 112 with destination system 122. Controller 130 may initiate the migration process in response to receiving a command or message (e.g., a request from a human user to execute the migration process). In some implementations, the migration process may include defining a consistency group that includes all replicated volumes on source storage device 110 (i.e., volumes replicated to source replication device 115) and also includes a virtual control volume that does not contain data content. The migration process may also include transferring replicated volumes from source storage device 110 to destination storage device 120 and then initiating data replication from destination storage device 120 to destination replication device 125. Further, after data replication is complete, the migration process may include transferring the control volume from source storage device 110 to destination storage device 120, thereby completing the migration of the consistency group. In this way, the migration process can be completed while maintaining data storage and replication. References below... Figures 2 to 3F The example migration process is described in more detail.

[0026] Figures 2 to 3F - Example migration process

[0027] Figure 2 An example migration process 200 according to some implementations is illustrated. Process 200 can be implemented in hardware or a combination of hardware and programming (e.g., machine-readable instructions executable by (multiple) processors). The machine-readable instructions can be stored in a non-transitory computer-readable medium such as an optical storage device, a semiconductor storage device, or a magnetic storage device. The machine-readable instructions can be executed by a single processor, multiple processors, a single processing engine, multiple processing engines, etc. For illustrative purposes, reference can be made below to an example implementation shown. Figure 1 and Figures 3A to 3F The details of process 200 will be described below. However, other implementations are also possible.

[0028] Box 210 may include receiving a request to initiate a migration from a source storage system to a destination storage system. Box 220 may include establishing a migration link between the source storage device and the destination storage device. Box 230 may include establishing a replication link between the destination storage device and the destination replication device. For example, refer to... Figure 3AThe source storage device 110 receives data input / output (I / O) from the client device 105 via data link 316. Further, the source storage device 110 stores data in the replicated volume 310, which is automatically copied to the source replication device 115. Subsequently, the controller 130 receives a request (e.g., a user command, program instruction, etc.) to initiate a migration from the source system 112 to the destination system 122. In response to the request, the controller 130 establishes a migration link 312 between the source storage device 110 and the destination storage device 120. Further, the controller 130 establishes a replication link 314 between the destination storage device 120 and the destination replication device 125.

[0029] Refer again Figure 2 Box 240 may include creating a set of proxy volumes on the destination storage device that are associated with a set of replicated volumes on the source storage device. For example, refer to Figure 3B The controller initiates or registers proxy volumes 330 on destination storage device 120 (also referred to as "permitting" proxy volumes 330 on destination storage device 120). Each proxy volume 330 represents a different replicated volume 310 on source storage device 110 (or is otherwise associated with a different replicated volume). When each proxy volume 330 is registered or permitted on destination storage device 120, the proxy volume 330 is regarded by client device 105 as representing the corresponding replicated volume 310.

[0030] Refer again Figure 2 Box 250 may include establishing a data link between the client device and the destination storage device. For example, refer to Figure 3B The controller establishes a data link 322 between the client device 105 and the destination storage device 120. Further, the client device 105 sends data I / O to the proxy volume 330 via the data link 322, and the proxy volume 330 forwards these data I / O (indicated by the dashed arrow 326) to the corresponding replicated volume 310 (e.g., via the migration link 312).

[0031] Refer again Figure 2 Box 260 may include creating a control volume on the source storage device. For example, refer to... Figure 3B The controller creates a control volume 320 on the source storage device 110. In some implementations, the control volume 320 is a virtual volume that does not contain any data and is used to control the progress of migration from the source system 112 to the destination system 122.

[0032] Refer again Figure 2 Box 270 may include creating a consistency group that includes the replicated volume and the control volume of the source storage device. For example, refer to Figure 3CThe controller creates a consistency group 340 comprising the replicated volume 310 and the control volume 320 (on the source storage device 110). As used herein, the term "consistency group" refers to a specified set of data elements (e.g., volumes, documents, etc.) that are migrated together (e.g., during a single migration operation). In some implementations, the creation of consistency group 340 initiates or defines a grouped migration that does not complete until all data elements in consistency group 340 (i.e., both replicated volume 310 and control volume 320) have been fully migrated to destination storage device 120. Further, the controller removes the data link 316 between client device 105 and source storage device 110.

[0033] Refer again Figure 2 Box 280 may include initiating a data copy from the replicated volume on the source storage device to the proxy volume on the destination storage device based on a consistency group. For example, refer to Figure 3C The controller initiates a data copy 342 from the replicated volume 310 to the proxy volume 330 (e.g., via migration link 312). The data copy 342 may be performed based on (or according to) a consistency group 340. For example, in some implementations, the data copy 342 transfers a copy of the first portion of the consistency group 340 (i.e., the replicated volume 310) to the destination storage device 120, but does not transfer a copy of the second portion of the consistency group 340 (i.e., the control volume 320) to the destination storage device 120. Thus, the consistency group 340 is not fully migrated when the data copy 342 is completed (i.e., by copying only the data from the replicated volume 310 to the destination storage device 120).

[0034] In some implementations, storage systems 112, 122 can continue to perform migration operations while data copy 342 is being performed. For example, proxy volume 330 can continue to forward data I / O to the replicated volume 310 on the source storage device 110, and the replicated volume 310 on the source storage device 110 can continue to be copied to the replica storage device 115.

[0035] Refer again Figure 2 Box 290 may include: initiating a replication of the proxy volume from the destination storage device to the destination replication device upon completion of the data copy. For example, refer to Figure 3D The controller determines that data copy 342 has been completed, and in response, initiates data copy 344 (e.g., via copy link 314) of the proxy volume 330 from the destination storage device 120 to the destination replication device 125. Data copy 344 may create the copied volume 310 on the destination replication device 125.

[0036] In some implementations, storage systems 112, 122 can continue to perform migration operations while data replication 344 is being performed. For example, proxy volume 330 can continue to forward data I / O to the replicated volume 310 on the source storage device 110, and the replicated volume 310 on the source storage device 110 can continue to be replicated to the replica storage device 115.

[0037] Refer again Figure 2 Box 295 may include: copying the control volume from the source storage device to the destination storage device upon completion of the agent volume replication. Following box 295, process 200 may be completed. For example, refer to... Figure 3E The controller 130 determines that the data copy 344 has been completed, and in response, performs a data copy 352 (e.g., via migration link 314) to copy the control volume 320 from the source storage device 110 to the destination storage device 120.

[0038] In some implementations, copying the control volume 320 to the destination storage device 120 completes the migration of the consistency group 340 (including the copied volume 310 and the control volume 320). Further, during the migration of the consistency group 340, one or more actions may be performed to complete the switch from the source system 112 to the destination system 122. For example, refer to... Figure 3F Controller 130 deletes consistency group 340, deletes copies of control volume 320 (in source storage device 110 and destination storage device 120), and also removes migration link 312. Further, controller 130 converts agent volume 330 into replicated volume 310 on destination storage device 120. After converting agent volume 330 into replicated volume 310 on destination storage device 120, these replicated volumes 310 no longer forward data I / O to replicated volume 310 on source storage device 110. More precisely, data I / O is applied only to replicated volume 310 on destination storage device 120 and replicated on destination replication device 125. Subsequently, storage system 112 is no longer updated with new data and can therefore store stale data 360 (e.g., older copies of replicated volume 310) or can be taken offline.

[0039] Figure 4 - Sample Management System

[0040] Figure 4 A schematic diagram of an example management system 400 is shown. In some examples, the management system 400 may substantially correspond to the controller 130 (e.g., Figure 1Some or all of the following are shown. As shown, the management system 400 may include a controller 402 and a machine-readable storage device 405 including instructions 410-450. The machine-readable storage device 405 may be a non-transitory medium. Instructions 410-450 may be executed by the controller 402 or by a processing engine included in the controller 402.

[0041] Instruction 410 can be executed to establish a migration link between a first storage device and a second storage device, wherein the first storage device stores a set of replicated volumes replicated on the first replication device. For example, refer to... Figure 3A The source storage device 110 receives data input / output (I / O) from the client device 105 and stores the data in a replicated volume 310 that is automatically copied to the source replication device 115. The controller 130 receives a request to initiate a migration and, in response, establishes a migration link 312 between the source storage device 110 and the destination storage device 120. In some embodiments, the controller 130 establishes a replication link 314 between the destination storage device 120 and the destination replication device 125, and permits a proxy volume 330 on the destination storage device 120. Further, refer to... Figure 3B The controller 130 allows the proxy volume 330 on the destination storage device 120, establishes a data link 322 between the client device 105 and the destination storage device 120, and creates a control volume 320 on the source storage device 110.

[0042] Instruction 420 can be executed to create a consistency group comprising the set of replicated volumes and a control volume stored on the first storage device, wherein the consistency group is a set of data elements that migrate together. For example, refer to... Figure 3C The controller creates a consistency group 340 that includes the replicated volume 310 (stored on the source storage device 110) and the control volume 320. Further, the controller removes the data link 316 between the client device 105 and the source storage device 110.

[0043] Instruction 430 can be executed to initiate a data copy from a group of replicated volumes to a group of proxy volumes on a second storage device based on a consistency group, wherein the proxy volumes forward input / output (I / O) transactions to the group of replicated volumes. For example, refer to... Figure 3B Client device 105 sends data I / O to proxy volume 330 via data link 322. Proxy volume 330 forwards the received data I / O (indicated by dashed arrow 326) to the corresponding replicated volume 310 (e.g., via migration link 312). Further, refer to... Figure 3C The controller initiates a data copy 342 from the replicated volume 310 to the proxy volume 330 (e.g., via migration link 312). The data copy 342 is performed based on the consistency group 340.

[0044] Instruction 440 can be executed to initiate a replication of the group of proxy volumes from the second storage device to the second replication device in response to the completion of a data copy from the group of replicated volumes to the group of proxy volumes. For example, refer to Figure 3D The controller determines that data copy 342 has been completed and, in response, initiates data copy 344 (e.g., via copy link 314) from the agent volume 330 from the destination storage device 120 to the destination copy device 125. Data copy 344 will be stored on the destination copy device 125 by the copy volume 310.

[0045] Instruction 450 can be executed to transfer a copy of the control volume from the first storage device to the second storage device in response to the completion of the replication of the group of agent volumes from the second storage device to the second replication device, wherein transferring the copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device. For example, refer to... Figure 3E The controller determines that data replication 344 has been completed and, in response, performs data copy 352 (e.g., via migration link 314) to copy control volume 320 from source storage device 110 to destination storage device 120. In some implementations, copying control volume 320 to destination storage device 120 completes the migration of consistency group 340 (including replicated volume 310 and control volume 320).

[0046] In some implementations, after (or as part of) the migration of consistency group 340 is complete, one or more actions may be performed to complete the switchover from source system 112 to destination system 122. For example, refer to Figure 3F The controller deletes consistency group 340, deletes copies of control volume 320 (in source storage device 110 and destination storage device 120), and also removes migration link 312. Further, the controller 130 converts agent volume 330 into replicated volume 310 on destination storage device 120.

[0047] Figure 5 Example Process

[0048] Figure 5 An example process 500 according to some implementations is shown. In some examples, process 500 may be handled by a processor or controller (e.g., Figure 1The process 500 is executed by the controller 130 shown. It can be implemented in hardware or a combination of hardware and programming (e.g., machine-readable instructions executable by (multiple) processors). The machine-readable instructions can be stored in a non-transitory computer-readable medium such as an optical storage device, a semiconductor storage device, or a magnetic storage device. The machine-readable instructions can be executed by a single processor, multiple processors, a single processing engine, multiple processing engines, etc. However, other implementations are also possible.

[0049] Box 510 may include establishing a migration link between a first storage device and a second storage device by the controller, wherein the first storage device stores a set of replicated volumes replicated on the first replication device. Box 520 may include creating a consistency group by the controller, comprising the set of replicated volumes and a control volume stored on the first storage device, wherein the consistency group is a set of data elements migrated together.

[0050] Box 530 may include the controller initiating a data copy from a group of replicated volumes to a group of proxy volumes on a second storage device based on a consistency group, wherein the proxy volumes forward input / output (I / O) transactions to the group of replicated volumes. Box 540 may include: in response to the completion of the data copy from the group of replicated volumes to the group of proxy volumes, the controller initiating a copy of the group of proxy volumes from the second storage device to the second replicated device.

[0051] Box 550 may include: in response to the completion of replication of the group of agent volumes from the second storage device to the second replication device, the controller transfers a copy of the control volume from the first storage device to the second storage device, wherein transferring the copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device. Boxes 510-550 may generally correspond to the reference instructions 410-450 above (e.g., Figure 4 (As shown in the image) is an example described.

[0052] Figure 6 - Example machine-readable medium

[0053] Figure 6 A machine-readable medium 600 storing instructions 610-650 is shown according to some embodiments. Instructions 610-650 can be controlled by a controller (e.g., Figure 1 The controller 130 shown (e.g., a single processor, multiple processors, a single processing engine, multiple processing engines, etc.) executes the commands. The machine-readable medium 600 can be a non-transitory storage medium, such as an optical storage medium, a semiconductor storage medium, or a magnetic storage medium. Instructions 610-650 can generally correspond to the referenced instructions 410-450 above (e.g., ...). Figure 4 (As shown in the image) is an example described.

[0054] Instruction 610 can be executed to establish a migration link between a first storage device and a second storage device, wherein the first storage device stores a set of replicated volumes replicated on the first replication device. Instruction 620 can be executed to create a consistency group comprising the set of replicated volumes and a control volume stored on the first storage device, wherein the consistency group is a set of data elements migrated together. Instruction 630 can be executed to initiate a data copy from the set of replicated volumes to a set of proxy volumes on the second storage device based on the consistency group, wherein the proxy volumes forward input / output (I / O) transactions to the set of replicated volumes.

[0055] Instruction 640 can be executed to initiate a replication of the group of proxy volumes from the second storage device to the second replication device in response to the completion of the data copy from the group of replica volumes to the group of proxy volumes. Instruction 650 can be executed to transfer a copy of the control volume from the first storage device to the second storage device in response to the completion of the replication of the group of proxy volumes from the second storage device to the second replication device, wherein transferring a copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device.

[0056] in conclusion

[0057] According to some implementations described herein, a controller can perform a migration process to replace a source storage system with a destination storage system. The source and destination storage systems may each include a primary storage device and a secondary replication device. In some implementations, the migration process may include defining a consistency group that includes all replicated volumes on the source storage device and a virtual control volume that does not contain data content. The migration process may also include transferring replicated volumes from the source storage device to the destination storage device and initiating data replication from the destination storage device to the destination replication device. Further, after data replication is complete, the migration process may include transferring the control volume from the source storage device to the destination storage device, thereby completing the migration of the consistency group. In this way, the migration process can be completed while maintaining data storage and replication.

[0058] Note that, although Figures 1 to 6 Various examples are shown, but the implementation methods are not limited in this respect. For example, see references... Figure 1 System 100 can be envisioned to include additional devices and / or components, fewer components, different components, different arrangements, etc. In another example, each of devices 110, 115, and 125 can be envisioned to also include a controller for managing the operation of the respective device 110, 115, or 125. In yet another example, the functionality of the aforementioned system 100 can be envisioned to be included in any other engine or software. Other combinations and / or variations are also possible.

[0059] Data and instructions are stored in a corresponding storage device implemented as one or more computer-readable or machine-readable storage media. Storage media include various forms of non-transitory memory, including: semiconductor memory devices such as dynamic random access memory or static random access memory (DRAM or SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), and flash memory; magnetic disks such as fixed floppy disks and removable disks; other magnetic media, including magnetic tape; optical media such as optical discs (CDs) or digital video discs (DVDs); or other types of storage devices.

[0060] Note that the instructions discussed above may be provided on a single computer-readable or machine-readable storage medium, or alternatively, on multiple computer-readable or machine-readable storage media distributed across a large system with potentially multiple nodes. Such one or more computer-readable or machine-readable storage media are considered part of an article (or artifact). An article or artifact can refer to any single or multiple manufactured components. The one or more storage media may be located in a machine executing the machine-readable instructions, or at a remote site from which the machine-readable instructions can be downloaded for execution via a network.

[0061] In the foregoing description, numerous details have been set forth to facilitate understanding of the subject matter disclosed herein. However, embodiments may be practiced without some of these details. Other embodiments may include modifications and variations of the details discussed above. The appended claims are intended to cover such modifications and variations.

[0062] In this disclosure, unless the context clearly indicates otherwise, the terms “a,” “an,” or “the” are intended to include the plural form as well. Similarly, when used in this disclosure, the terms “includes / including / comprises / comprising” or “have / having” indicate the presence of the stated element but do not preclude the presence or addition of other elements.

Claims

1. A management system, the management system comprising: Controller; as well as A machine-readable storage device storing instructions that can be executed by a processor to perform the following operations: Establish a migration link between a first storage device and a second storage device, wherein the first storage device stores a set of replicated volumes replicated on the first replication device; Create a consistency group comprising the set of replicated volumes and control volumes stored on the first storage device, wherein the consistency group is a set of data elements that migrate together; Based on the consistency group, a data copy is initiated from the group's replicated volume to a group of proxy volumes on the second storage device, wherein the proxy volumes forward input / output I / O transactions to the group's replicated volume; In response to the completion of the data copy from the group of replicated volumes to the group of agent volumes, initiate the copy of the group of agent volumes from the second storage device to the second replicated device; and In response to the completion of the replication of the group of agent volumes from the second storage device to the second replication device, a copy of the control volume is transferred from the first storage device to the second storage device, wherein transferring the copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device.

2. The management system of claim 1, further comprising instructions executable by the controller to perform the following operations: The control volume is created as an empty volume included in the first storage device.

3. The management system of claim 1, further comprising instructions executable by the controller to perform the following operations: After the migration of the consistency group is completed, the group of agent volumes is converted into a second group of replicated volumes replicated on the second replication device.

4. The management system of claim 1, further comprising instructions executable by the controller to perform the following operations: After the migration of the consensus group is completed: Delete the consensus group; Delete the control volume stored on the first storage device; and Delete the control volume stored on the second storage device.

5. The management system of claim 1, further comprising instructions executable by the controller to perform the following operations: The data copy is performed using the migration link between the first storage device and the second storage device; and After the migration of the consistency group is completed, the migration link between the first storage device and the second storage device is removed.

6. The management system of claim 1, further comprising instructions executable by the controller to perform the following operations: Establish a first data link between the client device and the second storage device; The I / O transaction is received from the client device via the first data link; as well as Remove the second data link between the client device and the first storage device.

7. The management system as described in claim 1, wherein, The control volume is not copied to the first copying device.

8. The management system as described in claim 1, wherein, The first storage device and the first replication device use a first storage technology, and the second storage device and the second replication device use a second storage technology different from the first storage technology.

9. The management system as described in claim 1, wherein, The controller is included in one of the second storage device and the system management device.

10. A method for data migration, the method comprising: The controller establishes a migration link between the first storage device and the second storage device, wherein the first storage device stores a set of replicated volumes replicated on the first replication device; The controller creates a consistency group comprising the set of replicated volumes and control volumes stored on the first storage device, wherein the consistency group is a set of data elements that are migrated together; The controller initiates a data copy from the group of replicated volumes to a group of proxy volumes on the second storage device based on the consistency group, wherein the proxy volumes forward input / output I / O transactions to the group of replicated volumes; In response to the completion of the data copy from the group of replicated volumes to the group of agent volumes, the controller initiates a copy of the group of agent volumes from the second storage device to the second replicated device; and In response to the completion of the replication of the group of agent volumes from the second storage device to the second replication device, the controller transfers a copy of the control volume from the first storage device to the second storage device, wherein transferring the copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device.

11. The method of claim 10, comprising: Establish a first data link between the client device and the second storage device; The I / O transaction is received from the client device via the first data link; The control volume is created as an empty volume included in the first storage device; as well as Remove the second data link between the client device and the first storage device.

12. The method of claim 10, further comprising, after completing the migration of the consistent group: Remove the migration link between the first storage device and the second storage device; and Convert the group of agent volumes into a second group of replicated volumes that are replicated on the second replication device.

13. The method of claim 12, further comprising, after completing the migration of the consistent group: Delete the consensus group; Delete the control volume stored on the first storage device; and Delete the control volume stored on the second storage device.

14. The method of claim 10, wherein, The first storage device and the first replication device use a first storage technology, and the second storage device and the second replication device use a second storage technology different from the first storage technology.

15. The method of claim 10, wherein, The controller is included in one of the second storage device and the system management device.

16. A non-transitory machine-readable medium storing instructions that, when executed, cause a controller to perform the following operations: Establish a migration link between the first storage device and the second storage device, wherein, The first storage device stores a set of replicated volumes copied to the first copying device; Create a consistency group comprising the set of replicated volumes and control volumes stored on the first storage device, wherein the consistency group is a set of data elements that migrate together; Based on the consistency group, a data copy is initiated from the group's replicated volume to a group of proxy volumes on the second storage device, wherein the proxy volumes forward input / output I / O transactions to the group's replicated volume; In response to the completion of the data copy from the group of replicated volumes to the group of agent volumes, initiate the copy of the group of agent volumes from the second storage device to the second replicated device; and In response to the completion of the replication of the group of agent volumes from the second storage device to the second replication device, a copy of the control volume is transferred from the first storage device to the second storage device, wherein transferring the copy of the control volume to the second storage device completes the migration of the consistency group from the first storage device to the second storage device.

17. The non-transitory machine-readable medium of claim 16, further comprising instructions that, when executed, cause the controller to perform the following operations: Establish a first data link between the client device and the second storage device; The I / O transaction is received from the client device via the first data link; The control volume is created as an empty volume included in the first storage device; as well as Remove the second data link between the client device and the first storage device.

18. The non-transitory machine-readable medium of claim 16, further comprising instructions that, when executed, cause the controller to perform the following operations: After the migration of the consensus group is completed: Remove the migration link between the first storage device and the second storage device; and Convert the group of agent volumes into a second group of replicated volumes that are replicated on the second replication device.

19. The non-transitory machine-readable medium of claim 16, further comprising instructions that, when executed, cause the controller to perform the following operations: After the migration of the consensus group is completed: Delete the consensus group; Delete the control volume stored on the first storage device; and Delete the control volume stored on the second storage device.

20. The non-transitory machine-readable medium of claim 16, wherein, The first storage device and the first replication device use a first storage technology, and the second storage device and the second replication device use a second storage technology different from the first storage technology.

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