Huawei OceanStor 2200 V3, OceanStor 2600 V3 Video Surveillance Edition, OceanStor 5600 V3, OceanStor 5800 V3, OceanStor 6800 V3 Features Manual

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OceanStor V3 Series

V300R006

Remote Replication Feature Guide for Block

Issue 06

Date 2018-01-30

HUAWEI TECHNOLOGIES CO., LTD.

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No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.

Trademarks and Permissions

and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd. All other trademarks and trade names mentioned in this document are the property of their respective holders.

Notice

The purchased products, services and features are stipulated by the contract made between Huawei and the customer. All or part of the products, services and features described in this document may not be within the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements, information, and recommendations in this document are provided "AS IS" without warranties, guarantees or representations of any kind, either express or implied.

The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to ensure accuracy of the contents, but all statements, information, and recommendations in this document do not constitute a warranty of any kind, express or implied.

Huawei Technologies Co., Ltd.

Address: Huawei Industrial Base

Bantian, Longgang Shenzhen 518129 People's Republic of China

Website: http://e.huawei.com

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DANGER

OceanStor V3 Series Remote Replication Feature Guide for Block

Purpose

This document describes the remote replication feature and provides an overview of its configuration, management, and usage scenarios.

Models of products supporting remote replication are as follows:

About This Document

Product Series

OceanStor 2000 V3 series OceanStor 2200 V3, 2600 V3, and 2600 V3

OceanStor 5000 V3 series OceanStor 5300 V3, 5500 V3, 5600 V3, and

OceanStor 6000 V3 series OceanStor 6800 V3

OceanStor 18000 V3 series OceanStor 18500 V3 and 18800 V3

Intended Audience

This document is intended for:

l Technical support engineers

l Maintenance engineers

Product Model

Video Surveillance Edition

5800 V3

Symbol Conventions

The symbols that may be found in this document are defined as follows.

Symbol

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Description

Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.

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WARNING

NOTE

OceanStor V3 Series Remote Replication Feature Guide for Block

Symbol Description

About This Document

Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.

Indicates a potentially hazardous situation which, if not avoided, could result in equipment damage, data loss, performance deterioration, or unanticipated results.

NOTICE is used to address practices not related to personal injury.

Calls attention to important information, best practices and tips.

NOTE is used to address information not related to personal injury, equipment damage, and environment deterioration.

Change History

Changes between document issues are cumulative. The latest document issue contains all the changes made in earlier issues.

Issue 06 (2018-01-30)

This issue is the sixth official release. The following sections are updated:

l Optimized descriptions about section Impact and Restrictions.

l Added description of the OceanStor 2600 V3 Video Surveillance Edition.

Issue 05 (2017-11-30)

This issue is the fifth official release. The updates are as follows:

Added description about the differences between V300R006C00 and V300R006C10.

Issue 04 (2017-08-30)

This issue is the fourth official release. The updates are as follows:

Document description is optimized.

Issue 03 (2017-08-10)

This issue is the third official release. The updates are as follows:

Document description is optimized.

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OceanStor V3 Series Remote Replication Feature Guide for Block

Issue 02 (2017-06-01)

This issue is the second official release. The updates are as follows:

l Document description is optimized.

l Added section Planning.

l Added section Verifying the Configuration.

l Added the Switching Local LUN Owning Controllers function.

l Changed Enable/Disable Protection for Secondary Resource to setting Status of

Secondary Resource Protection.

l Optimized the description about section Impact and Restrictions.

Issue 01 (2017-02-28)

This issue is the first official release.

About This Document

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OceanStor V3 Series Remote Replication Feature Guide for Block Contents

About This Document.....................................................................................................................ii

1 Feature Description....................................................................................................................... 1

1.1 Overview........................................................................................................................................................................ 1

1.2 License Requirements and Compatible Products........................................................................................................... 3

1.3 Principles........................................................................................................................................................................ 4

1.3.1 Related Concepts......................................................................................................................................................... 4

1.3.2 Data Replication.......................................................................................................................................................... 9

1.3.3 Service Switchover.................................................................................................................................................... 13

1.3.4 Data Recovery........................................................................................................................................................... 15

1.3.5 Functions of a Consistency Group.............................................................................................................................16

1.4 Impact and Restrictions................................................................................................................................................ 19

1.5 Application Scenarios...................................................................................................................................................20

2 Planning........................................................................................................................................ 29

3 Configuring Remote Replication............................................................................................. 31

3.1 Configuration Process...................................................................................................................................................32

3.2 Preparing for the Configuration....................................................................................................................................33

3.3 Checking the License File............................................................................................................................................ 34

3.4 (Optional) Adding Routes............................................................................................................................................ 35

3.5 Adding a Remote Device..............................................................................................................................................36

3.6 Creating a Remote Replication.....................................................................................................................................43

3.6.1 Creating a Synchronous Remote Replication (Applicable to V300R006C00)......................................................... 43

3.6.2 Creating a Synchronous Remote Replication (Applicable to V300R006C10)......................................................... 45

3.6.3 Creating an Asynchronous Remote Replication (Applicable to V300R006C00)..................................................... 50

3.6.4 Creating an Asynchronous Remote Replication (Applicable to V300R006C10)..................................................... 56

3.7 Creating a Consistency Group......................................................................................................................................62

3.8 Verifying the Configuration..........................................................................................................................................68

4 Configuration Example.............................................................................................................. 72

4.1 Central Backup and Disaster Recovery........................................................................................................................ 72

4.1.1 Requirement Analysis................................................................................................................................................72

4.1.2 Configuration Planning..............................................................................................................................................75

4.1.3 Configuration Operations.......................................................................................................................................... 82

4.1.4 Configuration Verification......................................................................................................................................... 92

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5 Disaster Recovery........................................................................................................................ 95

6 Managing Remote Replication............................................................................................... 102

6.1 Viewing Information of Remote Replication Pairs.................................................................................................... 103

6.2 Modifying the Properties of a Remote Replication Pair.............................................................................................108

6.3 Synchronizing a Remote Replication Pair.................................................................................................................. 113

6.4 Splitting a Remote Replication Pair............................................................................................................................114

6.5 Performing a Primary/Secondary Switchover for a Remote Replication................................................................... 115

6.6 Switching Local LUN Owning Controllers................................................................................................................ 116

6.7 Synchronizing Remote Status.....................................................................................................................................116

6.8 Deleting a Remote Replication Pair............................................................................................................................117

6.9 Viewing Remote Replication Performance Indicators................................................................................................119

7 Managing Consistency Groups.............................................................................................. 122

7.1 Viewing Consistency Group Information...................................................................................................................123

7.2 Changing the Properties of a Consistency Group.......................................................................................................132

7.3 Synchronizing a Consistency Group.......................................................................................................................... 136

7.4 Splitting a Consistency Group....................................................................................................................................137

7.5 Performing Primary/Secondary Switchover of a Consistency Group........................................................................ 139

7.6 Enabling Protection For Secondary Resource Of Consistency Groups..................................................................... 140

7.7 Disabling Protection For Secondary Resource Of Consistency Groups.................................................................... 141

7.8 Adding a Remote Replication Pair............................................................................................................................. 142

7.9 Removing a Remote Replication Pair........................................................................................................................ 143

7.10 Deleting a Consistency Group..................................................................................................................................144

8 Managing Remote Devices...................................................................................................... 146

8.1 Viewing Remote Device Information.........................................................................................................................146

8.2 Modifying Remote Device Information..................................................................................................................... 149

8.3 Modifying the Advanced Properties of a Remote Link..............................................................................................152

8.4 Deleting a Remote Link..............................................................................................................................................153

8.5 Removing a Remote Device....................................................................................................................................... 154

9 FAQs.............................................................................................................................................156

9.1 What Are the Differences Between Synchronous Remote Replication and Asynchronous Remote Replication......157

9.2 How Do I Use the Secondary LUN in a Remote Replication Task............................................................................ 158

9.3 Why Information About the Primary Device and the Secondary Device in a Remote Replication Task Cannot Be

Updated In Real Time.......................................................................................................................................................158

9.4 What Is the Relationship Among a Remote Replication Task, Clone, and Consistency Group................................ 159

9.5 What Is the Principle of Setting Bandwidth for Remote Replication and LUN Copy among Storage Arrays..........159

9.6 Precautions for Creating a Remote Link.................................................................................................................... 160

9.7 Functions of Reserved Space for an Asynchronous Remote Replication Task.......................................................... 160

9.8 Impact of Modifying Consistency Group Properties..................................................................................................161

9.9 When Performing a Remote Replication Task, Is an Initial Synchronization Required to Synchronize Data from the

Primary Storage System to the Secondary Storage System............................................................................................. 161

9.10 Do I need to stop the services on the primary storage system before performing the initial synchronization.........162

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9.11 Impact of the Secondary Storage System Failure on Remote Replication...............................................................162

9.12 Do File Remote Replication and Block Remote Replication Use the Same License...............................................162

9.13 How Can I Solve the Problem if the Logical Bandwidth and the Replication Link Bandwidth Are Not the Same in

Asynchronous Remote Replication.................................................................................................................................. 163

9.14 What Can I Do If the Remote Connection Fails to Be Created with the TOE Interface Module............................ 163

9.15 Will Synchronization Be Interrupted When Long Latency Occurs on the Links to the Two Ends of Synchronous

Remote Replication.......................................................................................................................................................... 164

9.16 Why the Secondary LUN Is not Displayed When the Remote Replication Pair Is Created.................................... 165

A Using the External Storage System to Perform Initial Synchronization for a Remote

Replication .................................................................................................................................... 166

A.1 Introduction................................................................................................................................................................166

A.2 Configuration Operation (Using the LUN Copy Feature of the External Storage System)...................................... 167

A.3 Configuration Operation (Using the LUN Copy Feature of the Production and DR Centers)..................................169

B How to Obtain Help................................................................................................................. 171

B.1 Preparations for Contacting Huawei..........................................................................................................................171

B.1.1 Collecting Troubleshooting Information.................................................................................................................171

B.1.2 Making Debugging Preparations............................................................................................................................ 172

B.2 How to Use the Document.........................................................................................................................................172

B.3 How to Obtain Help from Website............................................................................................................................ 172

B.4 Ways to Contact Huawei............................................................................................................................................ 172

C Glossary...................................................................................................................................... 173

D Acronyms and Abbreviations................................................................................................ 174

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OceanStor V3 Series Remote Replication Feature Guide for Block

About This Chapter

The remote replication feature provides flexible and powerful data replication functions including remote data backup and recovery, continuous support for service data, and disaster recovery.

1 Feature Description

1.1 Overview

This section describes the background, definition, purposes, and benefits of the remote replication feature.

1.2 License Requirements and Compatible Products

This section describes the availability of the remote replication feature in terms of license requirement and applicable versions.

1.3 Principles

This section describes how the remote replication feature replicates data, switches services, and recovers data, and introduces the function of a consistency group.

1.4 Impact and Restrictions

This section describes restrictions on the remote replication feature.

1.5 Application Scenarios

The remote replication feature is used for data backup and DR. The typical application scenarios include central backup and DR, and 3DC.

1.1 Overview

This section describes the background, definition, purposes, and benefits of the remote replication feature.

Background

As the digitalization drive advances in various industries, data has become critical to the operation of enterprises, and customers impose increasingly demanding requirements on the stability of storage systems. Although some storage devices offer extremely high stability, they fail to prevent irrecoverable damage to production systems caused by natural disasters. To ensure the consistency, recoverability, and high reliability of data access, remote disaster

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recovery solutions emerge. The remote replication technology is one of the key technologies used by remote disaster recovery solutions. HyperReplication is a remote replication feature developed by Huawei.

Definition

The remote replication feature developed by Huawei is called HyperReplication. When a storage system runs block services, remote replication supports the following two modes:

l Synchronous remote replication

In this mode, data is synchronized in real time to achieve full protection for data consistency and minimized data loss in the event of a disaster.

l Asynchronous remote replication

Data is synchronized periodically to minimize service performance deterioration caused by the long latency of long-distance data transmission.

Benefit

Table 1-1 lists the purposes and benefits of the remote replication feature.

1 Feature Description

Table 1-1 Purposes and benefits of the remote replication feature

Function of Remote Replication

Remote backup and recovery

Continuous support for services

Disaster recovery To recover data at the primary

Note 1: A primary site is a data center that includes the primary storage system, application servers, and links.

Note 2: A secondary site is a backup center that includes the secondary storage system, application servers, and links.

Note 3: Unless otherwise specified, hosts mentioned in this document refer to application servers.

Purpose Benefit

To recover service data using backup data in the remote storage system after the service data becomes unusable.

To quickly switch service data from the primary site to the secondary site, protecting service continuity.

site using backup data at the secondary site in the case of a disaster.

This feature prevents damage caused by data loss in the case that data at the primary site becomes unusable.

This feature prevents damage caused by a service interruption upon a failure at the primary site.

This feature prevents the damage caused by service data loss or long recovery duration.

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1 Feature Description

1.2 License Requirements and Compatible Products

This section describes the availability of the remote replication feature in terms of license requirement and applicable versions.

License Requirements

Remote replication requires a software license in both the primary and secondary storage systems.

Compatible Hardware

Table 1-2 and Table 1-3 list primary and secondary storage systems compatible with remote

replication.

Table 1-2 Primary storage systems that support remote replication

Product Series

OceanStor 2000 V3 series OceanStor 2200 V3, 2600

OceanStor 5000 V3 series OceanStor 5300 V3, 5500

OceanStor 6000 V3 series OceanStor 6800 V3 V300R006

OceanStor 18000 V3 series OceanStor 18500 V3 and

Table 1-3 Secondary storage systems that support remote replication

Product Series

OceanStor T series OceanStor S2600T/S5500T/

OceanStor 18000 series OceanStor 18500/18800 V100R001C00SPC200 and

Product Model Version

V300R006 V3, and 2600 V3 Video Surveillance Edition

V300R006 V3, 5600 V3, and 5800 V3

V300R006 18800 V3

Product Model Version

V200R002C00SPC200 and S5600T/S5800T/S6800T

later

OceanStor 18000F series OceanStor 18800F V100R001C00SPC200 and

OceanStor 18000 V3 series OceanStor 18500 V3/18800V3V300R003C00 and later

OceanStor 5000 V3 series OceanStor 5300 V3/5500

V3/5600 V3/5800 V3

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later

V300R001 and later

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Product Series Product Model Version

1 Feature Description

OceanStor 6000 V3 series OceanStor 6800 V3/6900

OceanStor 2000 V3 series OceanStor 2200 V3/2600

a: 6900 V3 is no longer supported in V300R002 and later versions.

Compatible Software

Product

OceanStor BCManager eReplication (BCManager eReplication for short)

a: To obtain the software installation package, log in to http://support.huawei.com/

enterprise/, in the search field, enter OceanStor BCManager, and select a path from the

paths that are automatically displayed to go to the document page. Then click the Downloads tab, and search and download your desired software files.

V300R001 and later

V300R005 and later

Version

l V200R001C10 (applicable to storage

system V300R006C00)

l V200R001C20 (applicable to storage

system V300R006C10)

NOTE

For asynchronous remote replication, it is advised to use the BCManager eReplication disaster recovery software if the synchronization interval is longer than 15 minutes. Because a host's cached data may not be completely delivered to the storage system when synchronization is triggered, data synchronized to the remote end may be inconsistent with that at the local end. BCManager eReplication can ensure data consistency between hosts at both ends. For details about BCManager eReplication, see the related User Guide and Compatibility List.

1.3 Principles

This section describes how the remote replication feature replicates data, switches services, and recovers data, and introduces the function of a consistency group.

1.3.1 Related Concepts

This section describes concepts related to the remote replication feature, including pair, consistency group, synchronization, splitting, primary/secondary switchover, data status and writable secondary LUN.

As shown in Figure 1-1, a remote replication task is implemented in five phases.

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OceanStor V3 Series Remote Replication Feature Guide for Block

Figure 1-1 Implementation of remote replication

Primary

storage system

Primary

LUN

Remote

replication links

Pair

Secondary

storage system

Secondary

LUN

1 Feature Description

1. Creating remote replication sessions

· The remote replication session corresponds to a pair.

· Multiple associated pairs can form a consistency group.

Phases in a full remote replication process

Primary

LUN

Secondary

LUN

Secondary

LUN

Primary

LUN

Remote

replication links

Pair

Remote

replication links

Pair’

Remote

replication links

Pair’

Remote

replication links

Pair

Secondary

LUN

Primary

LUN

Primary

LUN

Secondary

LUN

2. Replicating data

· Data is replicated during synchronization.

· Users can stop synchronization by performing a splitting operation.

3. Switching services

· The data status and secondary LUN’s accessible property show whether a primary/secondary switchover can be performed.

· A new pair is generated after a primary/secondary switchover.

4. Recovering data

Data recovery is implemented using synchronization.

5. Restoring pairs

The original pair is restored after another primary/secondary switchover.

Pair

A pair is the relationship between a primary logical unit number (LUN) and a secondary LUN in a remote replication task. Between pairs, data can be replicated only from the primary LUN to the secondary LUN, and only after a pair is established between the LUNs. To be paired, the primary and secondary LUNs must be in different storage systems.

The running status of a pair may change throughout a remote replication task. By viewing the running status of a pair, you can determine whether that pair requires further actions and, if so, what operation is required. After performing an operation, view the running status of the pair to check whether the operation has succeeded.

Table 1-4 describes the running status of pairs involved in a remote replication task.

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Table 1-4 Running status of a remote replication pair

Running Status Description

Normal Data synchronization between the primary and secondary LUNs is

Split Data replication between the primary and secondary LUNs is

Interrupted The running status of a pair changes to Interrupted after the pair

To be recovered If a remote replication task requires restoration using a Manual

1 Feature Description

complete.

NOTE

If Initial Synchronization is set to The data on primary and secondary resources is consistent and data synchronization is not required., a newly

created remote replication pair is in the Normal state.

suspended. The running status of a pair changes to Split after the primary and secondary LUNs are manually split by an administrator.

between the primary and secondary LUNs is interrupted. This occurs when the links used by a remote replication task are down or either LUN fails.

policy following recovery from the Interrupted state, the pair running status changes to To be recovered. This state is a notice to begin manual synchronization to restore the pair between the original primary and secondary LUNs.

Invalid If the original properties of a primary or secondary LUN change

Synchronizing Data is being copied from the primary to the secondary LUN. In this

Consistency Group

A consistency group is a collection of pairs that have a service relationship with each other. For example, the primary storage system has three primary LUNs, which respectively store service data, log, and change tracking information of a database. If data on any of the three LUNs becomes invalid, all data on the three LUNs becomes unusable. For these LUNs, you can create a consistency group, and add the remote replication sessions of the LUNs to the consistency group.

Synchronization

while a pair is Interrupted, the pair running status changes to Invalid because the primary and secondary system configurations

become inconsistent.

state, data on the secondary LUN is unavailable and cannot be used for service recovery if a disaster occurs. Only Consistent LUNs can be used to recover services.

Synchronization is a process of copying data from the primary to a secondary LUN. Synchronization can be performed for a single remote replication session or for multiple remote replication sessions in a consistency group at the same time.

Synchronization of a remote replication pair involves initial synchronization and incremental synchronization.

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l After an asynchronous remote replication task is created, initial synchronization is

performed to copy full data from the primary LUN to the secondary LUN. After the initial synchronization is complete, if the remote replication pair is normal, incremental data of the primary LUN will be synchronized to the secondary LUN based on the specified synchronization mode (manual or automatic). If the remote replication is interrupted due to a fault, incremental data will be synchronized from the primary to the secondary LUN based on the specified recovery policy (manual or automatic) after the fault is rectified.

l After a synchronous remote replication task is created, initial synchronization is

performed to copy full data from the primary LUN to the secondary LUN. After the initial synchronization is complete, if the remote replication pair is normal, host I/Os will be written into both the primary and secondary LUNs, not requiring data synchronization. If the remote replication is interrupted due to a fault, incremental data will be synchronized from the primary to the secondary LUN based on the specified recovery policy (manual or automatic) after the fault is rectified.

Synchronization can be classified into the following three scenarios based on the types of primary and secondary LUNs:

l The primary LUN is a thin LUN not configured with SmartDedupe&SmartCompression

and the secondary LUN is a thin LUN with no space allocated. During the initial synchronization, data for which space is not allocated on the primary LUN will not be synchronized to the secondary LUN.

l The primary LUN is a thick LUN or a thin LUN configured with

SmartDedupe&SmartCompression and the secondary LUN is a thin LUN with no space allocated. During the initial synchronization, data in the primary LUN is read in sequence and the consecutive 64 KB all zero data will not be synchronized to the secondary LUN.

l In other scenarios except the previous two, during the initial synchronization, the system

reads data in the primary LUN in sequence. The 64 KB all zero data is compressed to 4 KB (16:1), synchronized to the secondary LUN, decompressed to 64 KB, and then written to the secondary LUN. Other data is written to the secondary LUN in sequence.

1 Feature Description

Splitting

Splitting is a process of stopping replicating data from the primary to the secondary LUN. This operation can be performed only by the administrator. Splitting can be performed for a single remote replication session or multiple remote replication sessions in a consistency group at one time. After the splitting, the pair relationship between the primary LUN and the secondary LUN still exists and the access permission of hosts for the primary and secondary LUNs remains unchanged.

At some time, for example when the bandwidth is not enough to support critical services, you probably do not want to copy data from the primary LUN to the secondary LUN. In such cases, you can split the secondary LUN from the primary LUN to suspend data synchronization.

Users can effectively control a remote replication process by performing synchronization and splitting.

Primary/Secondary Switchover

A primary/secondary switchover is a process of exchanging the roles of the primary and secondary LUNs in a pair relationship. You can perform a primary/secondary switchover for a

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single remote replication session or multiple remote replication sessions in a consistency group at one time. A primary/secondary switchover is typically performed in the following scenarios:

l After the primary site recovers from disasters, the remote replication links are

reestablished and data is synchronized between the primary and secondary sites.

l When the primary storage system requires maintenance or an upgrade, the secondary

storage system must take control of services.

After a primary/secondary switchover, services run on the secondary storage system instead. Data on the secondary LUN must be available prior to the primary/secondary switchover. Determine whether data on the secondary LUN is available by viewing its data status.

Data Status

By determining differences between a primary and a secondary LUN, remote replication identifies the data status of the current pair. If a disaster occurs, remote replication determines whether to allow a primary/secondary switchover based on the data status of the pair. The acceptable data states are Consistent and Inconsistent.

Writable Secondary LUN

1 Feature Description

Hosts can send data to secondary LUNs. By default, the secondary LUN can only be read following configuration of remote replication. If the primary LUN fails, set Status of Secondary Resource Protection to Read/Write. This allows writing to the secondary LUN and ensures service continuity by allowing the secondary storage system to maintain host services. You must configure the secondary LUN to be writable in the following scenarios:

l The primary LUN fails and the remote replication link is in the disconnected state.

l The primary LUN fails and the remote replication link is in the normal state. The pair

Link Compression

In an asynchronous remote replication task, data is compressed on the primary storage system before transfer. That data is decompressed on the secondary storage system, reducing bandwidth use in data transfer. Link compression on the OceanStor storage systems provides the following advantages:

l Inline data compression

l Intelligent compression

l High reliability and security

l User unawareness

l Compatibility with full backup and incremental backup

must be split before you enable the secondary LUN to be writable.

Data is compressed when being transferred.

The system preemptively determines if data can be compressed, preventing unnecessary compression and improving transfer efficiency.

Lossless compression technology is used to ensure data security. Multiple check methods ensure data reliability. After receiving data, the secondary device verifies data correctness and checks data integrity after the data is decompressed.

Link compression does not affect services running on the host and is transparent to users.

Link compression compresses all data that is transferred over the network regardless of upper-layer services.

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Switching Over Owning Controllers of LUNs

OceanStor storage systems support switchover of owning controllers on local LUNs. The switchover on the primary storage switches over owning controllers of primary LUNs. The switchover on the secondary storage switches over owning controllers of secondary LUNs. In parallel networking, it is recommended to set the same owning controller for primary and secondary LUNs of a remote replication pair. For example, if primary LUNs belong to controller A, secondary LUNs also belong to controller A. If primary and secondary LUNs have different owning controllers, I/O forwarding is required, affecting performance.

1.3.2 Data Replication

Data replication is a process of writing service data generated by hosts to the secondary LUN in the secondary storage system for backup and disaster recovery. The writing process varies depending on the remote replication mode. This section describes data replication performed using synchronous and asynchronous remote replication sessions.

Writing Process in Synchronous Remote Replication

A synchronous remote replication session replicates data in real time from the primary storage system to the secondary storage system. The characteristics of synchronous remote replication are as follows:

l After receiving a write I/O request from a host, the primary storage system sends the

request to the primary and secondary LUNs.

l The data write result is returned to the host only after the data is written to both primary

and secondary LUNs. The data write result is determined by whether the data is successfully written to the primary LUN and is irrelevant to the secondary LUN. If data fails to be written to the primary LUN or secondary LUN, the primary LUN or secondary LUN returns a write I/O failure to the remote replication management module. Then, the remote replication management module changes the mode from dual-write to singlewrite, and the remote replication is interrupted.

After a synchronous remote replication pair is created with the primary LUN and the secondary LUN, you need to manually perform synchronization so that the two LUNs are consistent. Every time a host writes data to the storage system after synchronization, the data is copied from the primary LUN to the secondary LUN in real time. Figure 1-2 shows how a synchronous replication processes a write (N: Data block being written).

1 Feature Description

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Figure 1-2 Writing process in synchronous remote replication mode

1 Feature Description

Data block N

Primary

Cache

Primary

LUN

Primary

storage system

Host

Primary

Records the difference in the LOG

Data block N

LOG

Remote replication links

Primary

cache

Data block N

LUN

DCL

Secondary

Cache

Secondary

LUN

Secondary

storage system

LOG

Secondary

cache

Secondary

LUN

Write I/O result

Determination

· Saves the log to the DCL upon any write failure

Write I/O result

· Deletes the log if all writes are successful

RM: Remote replication management module.

LOG: Records data write logs.

DCL: Data change log.

NOTE

The DCL is stored on all the disks in the disk domain and four-disk RAID 1 is used for data protection while storage system logs are stored on coffer disks.

1. The host sends a write I/O request to the RM.

2. The RM records the write I/O request in the LOG.

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3. The RM concurrently writes the write I/O request to both the primary cache and secondary cache.

4. The primary cache and secondary cache return the write I/O result to the RM.

5. After receiving the response from the primary cache and secondary cache, a storage array returns the write I/O result to the host. If data fails to be written to the primary cache or secondary cache, the primary cache or secondary cache returns a write I/O failure to the RM. The RM then changes the mode from dual-write to single-write and the remote replication is interrupted.

6. The storage array determines whether dual-write succeeds. – If data has been successfully written to both the primary cache and secondary

cache, the LOG is deleted.

– If data fails to be written to the primary cache or secondary cache, the LOG is

stored in the DCL.

Writing Process in Asynchronous Remote Replication

Asynchronous remote replication sessions periodically replicate data from the primary to secondary storage systems. The principles of asynchronous remote replication are as follows:

l Asynchronous remote replication relies on the snapshot technology. A snapshot is a

point-in-time copy of source data.

l When a host successfully writes data to a primary LUN, the primary storage system

returns a response to the host declaring the successful write.

l Data synchronization is triggered manually or automatically at configured intervals.

When an asynchronous remote replication relationship is configured between primary and secondary LUNs, an initial synchronization begins. The initial synchronization copies all data from the primary to the secondary LUN to ensure data consistency.

1 Feature Description

When a host is writing to the primary storage system, the primary storage system sends the data to the primary LUN. If the write is successful, a response message will be sent from the primary LUN to the primary storage system and then to the host. At configured synchronization times, new data is copied from the primary to the secondary LUN. Figure

1-3 shows the writing process in asynchronous remote replication mode (N: Data block being

written).

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Figure 1-3 Writing process in asynchronous remote replication mode

Primary

Snapshot

storage system

Pri

mar

Data block N

Write I/O

result

Data block N

Write I/O

result

Host

Cache

LUN

Primary

Cache

Primary

LUN

Data block N

Records the difference in the DCL

DCL

Remote replication links

DCL

差异位图

Primary

LUN

Primary

LUN

snapshot

The primary LUN

snapshot is created

Secondary

Cache

Secondary

LUN

Snapshot

Secondary

storage system

Secondary

Cache

1 Feature Description

Secondary

LUN

Secondary

LUN

Secondary

LUN

snapshot

The secondary LUN

snapshot is created

Data is replicated from the primary cache and LUN to the secondary cache.

RM: Remote replication management module.

DCL: Data change log.

Eliminates the

difference in the DCL.

Incremental data is synchronized

to the secondary cache

Data block N

The primary LUN snapshot is stopped.

The secondary LUN snapshot is stopped.

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NOTE

The DCL is stored on all the disks in the disk domain and four-disk RAID 1 is used for data protection while storage system logs are stored on coffer disks.

When synchronization is started (synchronization is manually started or automatically triggered when the system reaches the synchronization period), snapshots of the primary and secondary LUNs are generated and activated. Snapshot functions are as follows:

l Primary LUN snapshot

Ensures that data read from the primary LUN during data synchronization is always consistent and allows for simultaneous implementation of data synchronization and data write to the primary LUN.

l Secondary LUN snapshot

Stores backup data for the data on the secondary LUN before synchronization so that data on the secondary LUN is still usable even if a failure occurs during synchronization.

The snapshot function is used only during data synchronization. After data synchronization is complete, the snapshot function stops to reduce system overhead and improve performance.

1. The host sends a write I/O request to the RM, and the RM directly writes data to the primary cache.

2. The primary cache returns the write I/O result to the RM, and the RM further returns the result to the host.

1 Feature Description

3. After data in the primary cache is written to the LUN, the RM records data differences between the primary LUN and the secondary LUN in the DCL.

4. When a replication period starts, the snapshots of the primary and secondary LUNs are activated.

5. Data is replicated from the primary cache and LUN to the secondary cache.

Asynchronous remote replication employs multi-time-point caching technology to replicate data from cache to the DR site. The working principle is as follows:

a. When a replication period starts, new time segments (T2 and P2) are respectively

generated in the caches of primary and secondary LUNs.

b. New data from the host is written to time segment T2 in the cache of the primary

LUN.

c. The primary LUN returns a message indicating that the write I/O operation is

complete.

d. Data in time segment T1 is replicated to time segment P2.

e. Data in the caches of the primary and secondary LUNs is written to LUNs.

6. The RM deletes differences recorded in the DCL after replicating data.

7. After the remote replication, the snapshot for the primary and secondary LUNs is stopped.

1.3.3 Service Switchover

When a disaster occurs at the primary site of a remote replication session, the secondary site can quickly take over primary site services to ensure business continuity.

The remote replication feature not only implements remote data backup but also recovers services as soon as possible in the case of a disaster to keep service continuity. The following two indicators need to be considered before a service switchover:

l RPO

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The maximum acceptable amount of time prior to a disaster wherein changes to data may be lost. Data changes preceding the disaster by longer than this amount of time are preserved via recovery. Synchronous remote replication copies data from a primary LUN to a secondary LUN in real time, ensuring that the Recovery Point Objective (RPO) is 0. Zero is a valid value and meets the "zero data loss" requirement. A remote disaster recovery system built based on synchronous remote replication implements data-level disaster recovery with a high disaster recovery level (tier 6—zero data loss). In asynchronous remote replication scenarios, the RPO is the time that you set for Interval.

l RTO

The maximum acceptable amount of time required to return one or more applications and associated data to a normal operational state after a disaster. The indicated recovery time serves as the objective and ensures that the standby host takes over services as quickly as possible. The Recovery Time Objective (RTO) depends on host services and disasters in remote replication scenarios.

Choose the remote replication mode based on the RPO and RTO requirements of users.

Service Switchover Through Remote Replication

Services can run on the secondary storage system only when the following conditions are met:

l Historical service data exists in the secondary storage system.

l Services on the production host have also been configured on the standby host.

l The secondary storage system allows a host to access a LUN in a LUN group mapped to

the host.

When a disaster occurs at the primary site, the remote replication links between the primary LUN and the secondary LUN go down. If this occurs, the administrator needs to manually change the access permission of secondary LUNs to accessible to enable a service switchover.

Figure 1-4 shows how a service switchover is implemented through remote replication.

1 Feature Description

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Figure 1-4 Service switchover through remote replication

1 Feature Description

Primary site

Production host

The production

host runs services.

Primary

LUN

Primary storage system Secondary storage system

Production host

Phases in a service switchover

Primary storage system Secondary storage system

Primary

LUN

Remote replication

links

Remote replication

links interrupted

Secondary site

Standby host

Read only

Secondary

LUN

Read only

Secondary

LUN

1. The primary site is working properly.

· The primary LUN is accessible to hosts but the secondary LUN is not.

· The primary site copies data to the secondary site.

2. The primary site encounters a disaster.

· The remote replication links are interrupted.

· The pair between the primary and

secondary LUNs is broken.

Production host

Primary storage system

NOTE

After a primary/secondary switchover, the respective primary and secondary sites record changed data to avoid full synchronization when the secondary site becomes the primary site.

1.3.4 Data Recovery

If a failure occurs at the primary site of a remote replication task, the secondary site temporarily takes over its services. When the primary site recovers, it regains control of those services.

Primary

LUN

Links interrupted

Standby host

The standby

Read

host takes over

/Write

Secondary storage system

services.

Secondary

LUN

3. The secondary site takes over services.

· Administrator sets the access permission of secondary LUNs manually to accessible.

· The secondary site takes over services from the primary site to ensure service continuity.

When the primary site recovers from a disaster, it is required to rebuild a remote replication between primary and secondary storage systems. And you can use the data on the secondary site to recover the primary site. Figure 1-5 shows how the storage system recovers data at the primary site after a disaster.

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Figure 1-5 Process of data recovery at the primary site following a disaster

1 Feature Description

Primary site

Production

host

Links restored

Secondary

LUN

Phases in a data recovery process

Primary storage

system

Production

host

Recovers data

New remote replication

Secondary

LUN

Primary storage system Secondary storage system

links

Secondary site

Standby host

Secondary storage

Standby host

The standby

host runs

services.

Primary

system

Primary

LUN

1. The primary site recovers from the

· The primary storage system recovers from the disaster. And the links between storage systems are

restored.

· After the links are restored, it is need to perform a primary/secondary switchover manually on the primary site, to make the secondary LUN on the secondary storage system

become the primary one.

2. The secondary site recovers data at the

· Synchronous: Perform synchronization once to copy data on the primary LUN

to the secondary LUN.

· Asynchronous: Perform synchronization for multiple times during idle hours to copy data on the

primary LUN to the secondary LUN.

disaster.

primary site.

Production

host

The

production

host runs services.

Primary storage system Secondary storage system

Primary

LUN

Remote replication

Standby host

NOTE

In asynchronous remote replication scenarios, the storage system performs data synchronization until data differences between the primary and secondary LUNs are minimal. The storage system then stops services and performs the final synchronization. This prevents data loss and minimizes downtime.

1.3.5 Functions of a Consistency Group

In medium- and large-sized database applications, data, logs, and modification information are stored on different LUNs that have relationships with each other. If data on one of the LUNs becomes unavailable, data on the other LUNs also becomes unavailable. Adding LUN pairs to a consistency group ensures the availability of data on the LUNs. This section compares storage systems running a consistency group with storage systems not running a consistency group to show you how a consistency group ensures business continuity.

Secondary

LUN

3. The primary site recovers services.

· Synchronous: Perform a primary/secondary switchover to

restore the pre-disaster pair.

· Asynchronous: Start synchronization again to eliminate the difference caused by host writes during the previous synchronization. Then split Pair to set the secondary LUN to be writable and perform a primary/secondary switchover to restore the pre-disaster pair.

· After recovered the pair, set the secondary resource protection status to read-only in the primary storage system.

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Users can perform synchronization, splitting, and primary/secondary switchovers for a single remote replication session or perform these operations for multiple remote replication sessions using a consistency group. Note the following when creating a consistency group:

l Remote replication sessions can be added to a consistency group only on the primary

storage system. In addition, secondary LUNs of all member remote replication sessions must be in the same remote storage system.

l LUNs of different member remote replication sessions in a consistency group can belong

to different working controllers.

l Remote replication sessions in the same consistency group must use the same remote

replication mode.

Remote Replication Without Using a Consistency Group

Data on LUNs not added to a consistency group is at risk for becoming unavailable, as shown in Figure 1-6.

1 Feature Description

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Figure 1-6 Remote replication without using a consistency group

Primary storage

system

Primary

LUN01

Primary

LUN02

Primary

LUN03

Before data

replication

Remote replication

session 01

Remote replication

session 02

Remote replication

session 03

Secondary storage

system

Secondary

LUN01

Secondary

LUN02

Secondary

LUN03

1 Feature Description

1. No consistency group is created.

· Data, log, and change tracking information of a database are respectively stored on primary LUN01, primary LUN02, and primary LUN03.

· No consistency group is created on the primary storage system.

Phases in a process of data becoming invalid

Primary

LUN01

Primary

LUN02

Primary

LUN03

Primary

LUN01

Primary

LUN02

Primary

LUN03

Data replication

Remote replication

session 01

Remote replication

session 02

Remote replication

session 03

Data recovery

Remote replication

session 01

Remote replication

session 02

Remote replication

session 03

Secondary

LUN01

Secondary

LUN02

Secondary

LUN03

Secondary

LUN01

Secondary

LUN02

Secondary

LUN03

2. A task failure causes data inconsistency.

· During synchronization, remote replication session 02 fails due to a fault.

· Remote replication sessions 01 and 03 succeed. As a result, data in the primary storage system becomes inconsistent with that in the secondary storage system.

3. Data becomes invalid.

· After the remote replication session failure, the secondary storage system recovers data in the primary storage system, but data in the primary storage system is still unusable because the three primary LUNs store data at different points in time.

Remote Replication Using a Consistency Group

If associated LUNs are added to a consistency group, data unavailability is prevented as shown in Figure 1-7.

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Figure 1-7 Remote replication using a consistency group

Primary storage

system

Primary

LUN01

Primary

LUN02

Primary

LUN03

Consistency group 01

Remote replication session

Secondary storage

system

Secondary

LUN01

Secondary

LUN02

Secondary

LUN03

1 Feature Description

1. Create a consistency group

· Data, log, and change tracking information of a database are respectively stored on primary LUN01, primary LUN02, and primary LUN03.

· Create consistency group 01 in the primary storage system and add the three remote replication sessions to the consistency group.

Consistency group 01

Remote replication session

Primary

LUN01

Remote replication session

Primary LUN02

Remote replication session

Primary

LUN03

Consistency group 01

Primary

Phases in a process in which a consistency group protects data availability

LUN01

Primary LUN02

Primary

LUN03

Remote replication session

2. The consistency group stops all remote

Secondary

LUN01

Secondary

LUN02

Secondary

LUN03

Secondary

LUN01

Secondary

LUN02

Secondary

LUN03

· During synchronization, remote

· The consistency group stops remote

· After the fault is rectified, the consistency

· In the event of a disaster, the secondary

replication sessions.

replication session 02 fails due to a fault.

replication sessions 01 and 03 immediately.

group resumes synchronization.

3. The consistency group protects data availability

storage system recovers data on the primary storage system. Data in the primary storage system is available immediately after the recovery.

1.4 Impact and Restrictions

This section describes restrictions on the remote replication feature.

Compatibility

When using HyperReplication, ensure that the host operating system, multipathing software, and the remote storage system are compatible with each other. You can query the compatibility using the OceanStor Interoperability Navigator.

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1.5 Application Scenarios

The remote replication feature is used for data backup and DR. The typical application scenarios include central backup and DR, and 3DC.

Different remote replication modes apply to different application scenarios.

l Synchronous remote replication applies to backup and DR scenarios where the primary

site is very near to the secondary site, for example, in the same city (same data center or campus).

l Asynchronous remote replication applies to backup and DR scenarios where the primary

site is far from the secondary site (for example, cross countries or regions) or the network bandwidth is limited.

NOTE

As for the asynchronous remote replication on an iSCSI network, you are advised to use a device such as a security gateway to encrypt links when adding the iSCSI links to ensure data transfer security among storage systems and prevent information leakage.

1 Feature Description

Different remote replication modes are used in different application scenarios. The modes are generally determined by distance and bandwidth between sites. Table 1-5 describes the typical application scenarios of HyperReplication and their conditions.

Table 1-5 Typical application scenarios of remote replication

Analysis Items

Scenario characteristics

Central Backup and DR 3DC

l Backup data is managed

l Three data centers (DCs)

centrally so that data analysis and data mining can be performed without affecting services.

l When a disaster occurs at

a service site, the central

l Service data is backed up

backup site can quickly take over services at the site and recover data, achieving unified service data management.

l When data in the

l The remote replication

mode can be selected for a service site flexibly based on the distance between the service site and the

l If a large-scale disaster

central backup site.

are deployed in two locations. Real-time backup and remote backup are available concurrently.

to the intra-city DR center in real time through a high-speed link.

production center is unavailable, services are quickly switched to the intra-city DR center.

occurs at both the production center and DR center in the same city, the remote DR center can take over services and implement DR.

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Analysis Items Central Backup and DR 3DC

1 Feature Description

Remote replication mode Synchronous remote

Maximum distance between primary and secondary sites

Central Backup and DR

In central backup and DR scenarios, service data distributed in different locations is backed up to the same site for centralized management. When a disaster occurs at a service site, the central backup site can take over services from the service site and recover data. Figure 1-8 shows a central backup and DR scenario.

Figure 1-8 Central backup and DR

replication or asynchronous remote replication

Synchronous remote replication: within 200 km

Asynchronous remote replication: no restriction

l Intra-city: synchronous

or asynchronous remote replication

l Remote: asynchronous

remote replication

Synchronous remote replication: within 200 km

Asynchronous remote replication: no restriction

Remote replication

Primary LUN 01

Service site 01

Primary LUN 02

Service site 02

...

Primary

LUN n

Service site n

Snapshot

session 01

Synchronous

Remote replication

session 02

Asynchronous

...

Remote replication

session n

Asynchronous

Secondary

LUN 01

Host

Secondary

LUN 02

...

Secondary

LUN n

Central backup site

Functions of remote replication are as follows:

l Collects data from service sites 01 to n, takes a snapshot of a secondary LUN, and maps

the secondary LUN to a host. The snapshot can be used for data analysis and data mining.

l Allows the central backup site to take over services when any service site (01 to n)

encounters a disaster and switch services back to the service site when the site recovers.

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l Implements real-time backup (using the synchronous remote replication mode) from

service site 01 to the central backup site, which is 500 m away from service site 01. Performs replication tasks (using the asynchronous remote replication mode) from service site 02 to the central backup site, which is 500 km away from service site 02.

3DC

3DC is a DR solution scenario in which three DCs are deployed across two different locations. The three DCs are the production center, intra-city DR site, and remote DR site. This version supports the 3DC configuration in the following modes: synchronous + asynchronous or asynchronous + asynchronous remote replication and HyperMetro + remote replication. Figure 1-9 shows the cascaded 3DC configuration in synchronous + asynchronous mode.

Figure 1-9 Cascaded 3DC configuration in synchronous + asynchronous mode

Site A

1 Feature Description

Storage System

Production

center

Site B

Storage System

Intra-city DR

center

LUN

Synchronous

Remote

Replication

LUN

Asynchronous

Remote

Replication

Site C

LUN

Storage System

Remote DR

center

Optical fiber cable

Network cable

The cascaded 3DC in synchronous + asynchronous mode meets the following service requirements:

l Real-time backup and remote backup of data ensure the reliability of critical service data

and ensure that critical service data has two copies.

l The cascaded 3DC has minor impact on the performance of the storage system in the

production center and does not affect host services.

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l When the production center (A) encounters a disaster, the intra-city DR center (B) takes

over services immediately and recovers data. If the secondary disaster damages the intracity DR center (B), data in the remote DR center (C) is available.

Figure 1-10 shows the cascaded 3DC in asynchronous + asynchronous mode.

Figure 1-10 Cascaded 3DC in asynchronous + asynchronous mode

Site A

Storage System

Production

center

1 Feature Description

LUN

Asynchronous

Remote

Replication

Site B

Storage System

Intra-city DR

center

LUN

Asynchronous

Remote

Replication

Site C

LUN

Storage System

Remote DR

center

Optical fiber cable

Network cable

The cascaded 3DC in asynchronous + asynchronous mode meets the following service requirements:

l Real-time backup and remote backup of data achieve robust reliability of critical service

data and ensure that critical service data has two copies.

l The cascaded 3DC has minor impact on the performance of the storage system in the

production center and does not affect host services.

l When a disaster occurs at the production center (A), the intra-city DR center (B) takes

over services immediately and recovers data. If the disaster also affects the intra-city DR center (B), data in the remote DR center (C) is still available.

Figure 1-11 shows the parallel 3DC configuration in synchronous + asynchronous mode.

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Figure 1-11 Parallel 3DC configuration in synchronous + asynchronous mode

Site A

Storage System

Production

center

Synchronous

Remote

Replication

1 Feature Description

LUN

Asynchronous

Remote

Replication

Site B

LUN

Storage System

Intra-city DR

center

Site C

LUN

Storage System

Remote DR

center

Optical fiber cable

Network cable

The parallel 3DC configuration in synchronous + asynchronous mode meets the following service requirements:

l Real-time backup and remote backup of data ensure the reliability of critical service data

and ensure that critical service data has two copies.

l Data backup of the remote DR center (C) does not depend on the intra-city DR center

(B). If the intra-city DR center (B) or remote DR center (C) fails, the production center (A) still has a backup site.

l When a disaster occurs at the production center (A), the intra-city DR center (B) takes

over services immediately and recovers data. If the disaster also affects the intra-city DR center (B), data in the remote DR center (C) is still available.

Figure 1-12 shows the parallel 3DC configuration in asynchronous + asynchronous mode.

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Figure 1-12 Parallel 3DC configuration in asynchronous + asynchronous mode

Site A

1 Feature Description

LUN

Storage System

Production

center

Site B

Storage System

Intra-city DR

center

Asynchronous

Remote

Replication

LUN

Asynchronous

Remote

Replication

Site C

LUN

Storage System

Remote DR

center

Optical fiber cable

Network cable

The parallel 3DC configuration in asynchronous + asynchronous mode meets the following service requirements:

l Real-time backup and remote backup of data ensure the reliability of critical service data

and ensure that critical service data has two copies.

l Data backup of the remote DR center (C) does not depend on the intra-city DR center

(B). If the intra-city DR center (B) or remote DR center (C) fails, the production center (A) still has a backup site.

l When a disaster occurs at the production center (A), the intra-city DR center (B) takes

over services immediately and recovers data. If the disaster also affects the intra-city DR center (B), data in the remote DR center (C) is still available.

NOTE

The difference between 3DC in synchronous + asynchronous and asynchronous + asynchronous modes lies in the different data synchronization modes of the production center (A) and intra-city DR center (B). For the data synchronization mode used by the 3DC in synchronous + asynchronous mode, when data is concurrently written to the production center (A) and intra-city DR center (B), a message is displayed indicating that the synchronization succeeds. For the data synchronization mode used by the 3DC in asynchronous + asynchronous mode, when data is concurrently written to the production center (A), a message is displayed indicating that the synchronization succeeds.

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Figure 1-13 shows the 3DC configuration in HyperMetro + asynchronous remote replication

mode.

Figure 1-13 3DC configuration in HyperMetro + asynchronous remote replication mode

1 Feature Description

Site A

Storage system

LUN

Production center

Optical fiber

Network cable

Site B

LUN

HyperMetro

Storage system

Same-city

production center

Asynchronous

remote

replication

Site C

LUN

Storage system

Remote DR center

NOTE

A remote replication relationship can be established between the remote DR center and either production center.

LUNs of two production centers in the same city form pairs and are accessible to application servers, achieving service load sharing and implementing intra-city DR for data. A remote replication relationship is established between HyperMetro member LUNs in the production center (A) or intra-city DR center (B) and LUNs in the remote DR center, implementing remote DR for data.

Using BCManager eReplication to Implement DR

BCManager eReplication is a DR management software program specially designed for Huawei typical DR solutions. It provides a visualized and process-based platform for simple and fast operations and monitoring, with data consistency, snapshot, and remote replication supported.

Figure 1-14 illustrates how to use BCManager eReplication to deploy a remote replication

task. Deploy the BCManager eReplication host in the DR center and install BCManager eReplication Server on the host. Install BCManager eReplication Agent on service hosts and DR hosts in the production center.

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Figure 1-14 Using BCManager eReplication to deploy remote replication

Production

host

BCManager

eReplication

Agent

Remote

replication

BCManager

eReplication

Server

1 Feature Description

DR centerProduction center

BCManager eReplication

Agent

DR hostBCManager

eReplication

host

Storage system

Figure 1-15 and Figure 1-16 illustrate how to use BCManager eReplication to deploy 3DC.

Deploy the BCManager eReplication hosts in DR centers 1 and 2 and install BCManager eReplication Server on the hosts. Install BCManager eReplication Agent on production hosts and DR hosts in the production center.

Figure 1-15 Using BCManager eReplication to deploy cascaded 3DC

DR center 2

eReplication

host

DR hostBCManager

Storage system

BCManager eReplication

Agent

Production

host

Storage system

BCManager

eReplication

Agent

Synchronous/ Asynchronous

remote

replication

BCManager

eReplication

Server

DR center 1Production center

eReplication

host

DR hostBCManager

Storage system

BCManager

eReplication

Agent

Asynchronous

remote

replication

BCManager

eReplication

Server

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Figure 1-16 Using BCManager eReplication to deploy parallel-connected 3DC

1 Feature Description

DR center 1

Production center

BCManager

eReplication

Agent

Production

host

Storage system

Synchronous/

Asynchronous

remote

replication

Asynchronous

remote replication

BCManager

eReplication

Server

BCManager

eReplication

Server

BCManager

eReplication

Agent

DR hostBCManager

eReplication

host

Storage system

DR center 2

BCManager

eReplication

Agent

DR hostBCManager

eReplication

host

Storage system

NOTE

For details about how to install, deploy, and configure BCManager eReplication, see the BCManager eReplication production documentation.

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This chapter describes the networks and data you must plan before remote replication configuration.

Network Planning

2 Planning

Remote replication involves a primary storage device and a secondary storage device. Therefore, you must plan the networking mode for remote replication and replication links between the storage devices before configuring remote replication.

Remote replication supports Fibre Channel and IP networks as well as Fibre Channel and iSCSI ports for replication. Based on application scenarios, the following three networking modes are available: direct connection using iSCSI host ports, direct connection using Fiber Channel host ports (multi-mode optical fibers), and connection through remote transfer devices (switches or routers). Table 2-1 provides the maximum transmission distance for remote replication in each networking mode.

Table 2-1 Maximum transmission distance for remote replication in different networking modes

Networking Mode

Direct connection using iSCSI host ports

Direct connection using Fiber Channel host ports (multimode optical fibers)

Connection through remote transfer devices (switches or routers)

Synchronous remote replication

100 m to 150 m 100 m to 150 m

500 m 500 m

200 km Not limited

Asynchronous Remote Replication

NOTE

If two storage devices are connected using a switch through Fibre Channel ports, it is recommended that their access ports on the switch be in the same zone. This ensures isolation between host service ports and inter-array replication service ports, minimizing the impact on each other.

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When planning replication links between storage devices, comply the following rules:

l Ensure that each controller of the primary storage device has a replication link to the

secondary storage device, which reduces I/Os forwarded between controllers. Otherwise, ensure that each controller enclosure of the primary storage device has a replication link to the secondary storage device.

l A maximum of eight available links can be identified between a controller and the

remote device. When you add a remote device, a maximum of eight links can be used for replication.

Data Planning

l Capacity planning

– Storage pool: Before configuring the remote replication feature, reserve 5‰ of the

LUN capacity in the storage pool where the primary and secondary LUNs reside. If you want to configure multiple value-added features on the primary or secondary LUN, reserve 1% of the LUN capacity in the storage pool. In addition, for asynchronous remote replication, reserve certain capacity in the storage pool to which the primary and secondary LUNs belong for pre-write copy. For details about space planning, see 9.7 Functions of Reserved Space for an Asynchronous

Remote Replication Task.

– LUN: The primary LUN and secondary LUN must have the same capacity.

l Bandwidth planning

– For synchronous remote replication, a write success response is returned only after

the data in each write request is written to the primary site and secondary site. If the primary site is far away from the secondary site, the write latency of applications is quite long, affecting user services. Therefore, synchronous remote replication applies to scenarios where the primary site is near to the secondary site, for example, intra-city disaster recovery. Normally, the disaster recovery distance of a metropolitan area network (MAN) is smaller than 200 km and the minimum network bandwidth must be or larger than 64 Mbit/s. The transmission latency must be smaller than 1 ms (single-way) and the actual network bandwidth must be larger than the peak service I/O write bandwidth.

– For asynchronous remote replication, the write latency of applications is

independent of the distance between the primary and secondary sites. As a result, asynchronous remote replication is applied in the disaster recovery scenario where the primary and secondary sites are far away from each other, or the network bandwidth is limited. Generally, there is no explicit limit on the WAN distance between the primary and secondary sites. It is recommended that the link bandwidth be greater than 10 Mbit/s (peak bandwidth/bandwidth usage), and the unidirectional transmission latency be smaller than 50 ms.

2 Planning

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3 Configuring Remote Replication

About This Chapter

Synchronous remote replication ensures data consistency between the primary resource and secondary resource of each remote replication pair. Asynchronous remote replication quickly responds to hosts' service requests and enables long-distance disaster recovery. Before configuring remote replication, you must understand the configuration process and check for the related license file. Then, configure link connectivity and parameters related to remote replication.

3 Configuring Remote Replication

3.1 Configuration Process

This section describes how to configure remote replication. You can set up a pair relationship between the primary resource and secondary resource to implement data synchronization.

3.2 Preparing for the Configuration

To successfully configure the remote replication feature, you must make preparations in advance, for example, obtaining the remote replication license, setting device information, and selecting host ports for data transmission.

3.3 Checking the License File

Remote replication is a value-added feature that requires a licence file. Before configuring remote replication, ensure that its license file is valid.

3.4 (Optional) Adding Routes

If iSCSI networking is adopted and data needs to be transmitted across network segments, you need to configure routes.

3.5 Adding a Remote Device

This operation enables you to establish a logical connection between a local storage device and a remote storage device for data transfer between the two devices.

3.6 Creating a Remote Replication

Remote replication copies data from a local storage device to a remote storage device for remote disaster recovery. Remote replication includes synchronous remote replication and asynchronous remote replication.

3.7 Creating a Consistency Group

Remote replication can implement data backup and disaster recovery in the scenario where a host writes data to a single or multiple independent primary LUNs. However, remote

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replication cannot implement data backup and disaster recovery in the scenario where a host writes data to multiple dependent primary LUNs. A consistency group ensures data consistency of secondary LUNs of all remote replication pairs in the group at the same point in time (for example, the data of all secondary LUNs are the data copy of its primary LUN at 3:00 PM today), therefore ensures the data availability of primary LUNs after disaster recovery.

3.8 Verifying the Configuration

After remote replication/consistency group is configured, you can view the status of the data on the primary and secondary storage systems to check whether data replication between the primary and secondary LUNs is successful.

3.1 Configuration Process

This section describes how to configure remote replication. You can set up a pair relationship between the primary resource and secondary resource to implement data synchronization.

Figure 3-1 shows the process of configuring remote replication.

Figure 3-1 Process for configuring remote replication

3 Configuring Remote Replication

Start

Prepare configuration

Check the remote

replication license

Add a route

Add a remote device

Create a remote

replication

Verify the Configuration

Obtain remote replication license and identify port type for connecting primary storage device and secondary storage

device.

When the local and remote storage systems connect through iSCSI host ports, and they locate on different network segments, add a route.

End

Note:

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NOTE

Unless otherwise stated, the preceding operations can be performed on either the primary or the secondary end. If you want to perform the operations on the secondary end, perform primary/secondary switchover first.

3.2 Preparing for the Configuration

Activating the License

Before configuring remote replication, import and activate its license file to enable the remote replication function to take effect.

l If you do not have its license, contact technical support to purchase the license.

l If you have purchased its license, follow instructions in Managing License File of the

Online Help to import the license file to the primary storage system and secondary storage system respectively and activate them.

3 Configuring Remote Replication

Setting Device Information

To distinguish between primary and secondary storage devices, you need to set the device information, including device names and locations, before configuring the remote replication

feature. Log in to DeviceManager and choose Device Information to set device information.

Selecting Host Ports

Remote replication supports data transmission based on FC host ports or iSCSI host ports.

l Fibre Channel port

Fibre Channel ports feature high transmission rate and low transmission latency. However, Fibre Channel ports use multi-mode optical fibers as transmission media. Multi-mode optical fibers support only a short transmission distance. Therefore, remote replication that uses Fibre Channel ports is suitable for short-distance backup and DR.

l iSCSI host port

Typically, iSCSI host ports are inferior to Fibre Channel ports in terms of transmission rate and latency. However, iSCSI host ports carry data by using the IP protocol. Therefore, data can be backed up to the secondary storage system through the Internet or dedicated cables, achieving remote backup and DR across cities, provinces, and even countries.

Settings > Basic Information >

Understanding the advantages and disadvantages of data transmission based on Fibre Channel ports and those of data transmission based on iSCSI host ports helps you select host ports that best meet service needs. After you select a host port type, the corresponding link type is also selected by default. In an actual networking scenario, you must also consider factors such as the bandwidth, latency, network quality, and security to ensure link efficiency and stability.

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3.3 Checking the License File

Remote replication is a value-added feature that requires a licence file. Before configuring remote replication, ensure that its license file is valid.

Context

On the DeviceManager interface, remote replication feature is displayed in Feature of HyperReplication(Remote Replication).

Precautions

The capacity of the remote replication license for 18000 V3 series or 18000F V3 series storage systems must be equal to or larger than the total capacity of LUNs equipped with this feature. However, if the total capacity of the LUNs in a storage pool equipped with this feature is larger than that of the storage pool, use the capacity of the storage pool to calculate the capacity required for the remote replication license. The following is a capacity calculation example.

3 Configuring Remote Replication

Procedure

Step 1 Log in to DeviceManager.

Step 2 Choose Settings > License Management.

Step 3 Check the active license files.

Storage Pool Name

StoragePool001 5 GB 10 GB 5 GB ≥25 GB

StoragePool002 10 GB 10 GB 10 GB

StoragePool003 20 GB 10 GB 10 GB

1. In the navigation tree on the left, choose Active License.

2. In the middle information pane, verify the information about active license files.

LUN Capacity (Total Capacity of Thin and Thick LUNs)

Capacity of the Storage Pool To Which LUNs Belong

License Capacity You Must Apply for the Storage Pool

Total License Capacity You Must Apply

----End

Follow-up Procedure

l If the license information about the remote replication feature is not displayed on the

Active License page, apply for and import a license file as instructed in the Installation Guide of the corresponding product model.

l If the storage system generates an alarm indicating that the license expired, purchase and

import another license file.

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3.4 (Optional) Adding Routes

If iSCSI networking is adopted and data needs to be transmitted across network segments, you need to configure routes.

Context

The Ethernet port has been assigned an IP address.

NOTE

In redundant links, you must configure IP addresses and routes for multiple Ethernet ports.

Procedure

Step 1 Log in to DeviceManager.

Step 2 Choose Provisioning > Port > Ethernet Ports.

3 Configuring Remote Replication

Step 3 Select the Ethernet port for which you want to add a route and click Route Management.

The Route Management dialog box is displayed.

Step 4 Configure the route information for the Ethernet port.

1. In IP Address, select the IP address of the Ethernet port.

2. Click Add.

The Add Route dialog box is displayed.

NOTICE

The default IP addresses of the internal heartbeat on a dual-controller storage system are

127.127.127.10 and 127.127.127.11, and the default IP addresses of the internal heartbeat on a four-controller storage system are 127.127.127.10, 127.127.127.11,

127.127.127.12, and 127.127.127.13. Therefore, the IP address of the router cannot fall within the 127.127.127.XXX segment. Besides, the IP address of the gateway cannot be

127.127.127.10, 127.127.127.11, 127.127.127.12, or 127.127.127.13. Otherwise, routing will fail. (Internal heartbeat links are established between controllers for these controllers to detect each other's working status. You do not need to separately connect cables. In addition, internal heartbeat IP addresses have been assigned before delivery, and you cannot change these IP addresses).

3. In Type, select the type of the route to be added.

There are three route options:

– Default route

Data is forwarded through this route by default if no preferred route is available. The destination address field and the target mask field (IPv4) or prefix (IPv6) of the default route are automatically set to 0. To use this option, you only need to add a gateway.

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– Host route

The host route is the route connecting to an individual host. The destination mask (IPv4: 255.255.255.255) or prefix (IPv6: 128) of the host route is automatically set. To use this option, you only need to add the target address and a gateway.

– Network segment route

The network segment route is the route connecting to a network segment. You need to add the target address, target mask (IPv4) or prefix (IPv6), and gateway. For example, the target address is 172.17.0.0, target mask is 255.255.0.0, and gateway is 172.16.0.1.

4. Set Destination Address.

– If IP Address is an IPv4 address, set Destination Address to the IPv4 address or

network segment of the application server's service network port or that of the other storage system's Ethernet port.

– If IP Address is an IPv6 address, set Destination Address to the IPv6 address or

network segment of the application server's service network port or that of the other storage system's Ethernet port.

5. Set Destination Mask (IPv4) or Prefix (IPv6).

– If Destination Mask is set for an IPv4 address, this parameter specifies the subnet

mask of the IP address for the service network port on the application server or the other storage device.

– If Prefix is set for an IPv6 address, this parameter specifies the prefix of the IPv6

address for the application server's service network port or that of the other storage system's Ethernet port.

6. In Gateway, enter the gateway of the local storage system's Ethernet port IP address.

3 Configuring Remote Replication

Step 5 Click OK. The route information is added to the route list.

A security alert dialog box is displayed.

Step 6 Confirm the information of the dialog box and select I have read and understood the

consequences associated with performing this operation..

Step 7 Click OK.

The Success dialog box is displayed, indicating that the operation succeeded.

NOTE

To remove a route, select it and click Remove.

Step 8 Click Close.

----End

3.5 Adding a Remote Device

This operation enables you to establish a logical connection between a local storage device and a remote storage device for data transfer between the two devices.

Prerequisites

l A local storage device is normally connected to the remote storage device.

l In scenarios where a firewall is deployed, ports 36061 and 3260 must be enabled for

adding a remote device.

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Context

The link between a local storage device and a remote storage device can be a Fibre Channel link or an iSCSI link.

NOTE

l On a Fibre Channel network, clear zone configurations of ports connecting to the storage system

from the switch before adding the remote device. You are advised to allocate two ports in one zone to prevent excessive remote links because too many ports in one zone.

l A maximum of eight links are available between a controller and a remote device, and

HyperReplication can use all of them as the replication links between the local and remote devices.

Procedure

Step 1 Log in to DeviceManager.

3 Configuring Remote Replication

Step 2 Choose

Data Protection > Remote Device.

Step 3 Click Add Remote Device.

The Wizard for Adding Remote Device dialog box is displayed.

Step 4 Select Replication, and click Next.

NOTICE

l If Running Status of an added link is Invalid, delete and add the link again.

l To ensure data transfer security among storage systems, you are advised to use a device

such as a security gateway to encrypt links to prevent information leakage.

l If the version of the local device is different from that of the remote device, you need to

add a remote device on the newer version device. Otherwise the operation may fail.

Step 5 Set up the connection to the remote device.

l Adding an iSCSI link

a. Set Link Type to iSCSI.

b. Set parameters for the iSCSI link. Table 3-1 lists related parameters.

Table 3-1 iSCSI link parameters

Parameter

Description Setting

Controller Name of the local storage device's

controller connected to the remote storage device.

Local Port Local storage device's Ethernet port

connected to the remote storage device.

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[Example]

CTE0.A

[Example]

CTE0.A.IMO1.P0

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Parameter Description Setting

3 Configuring Remote Replication

IP Address IP address of the Ethernet port on the

remote storage device.

Username The user used for communication

authentication between remote devices.

n If remote devices are OceanStor

18000 series V100R001C20, T series V200R002C20, or OceanStor V3 series V300R001C10 or later, you need to use the machine-machine user.

n If remote devices are OceanStor

18000 series V100R001C10, T series V200R002C10, or OceanStor V3 series V300R001C00 or earlier, you need to use the super administrator or administrator account on the older version remote device.

[Example]

192.168.26.12

[Value]

n The default

username of the machinemachine user is mm_user.

n Obtain the super

administrator or administrator account on the remote device.

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Parameter Description Setting

3 Configuring Remote Replication

Password Password of the user used for

communication authentication between remote devices.

n If remote devices are OceanStor

18000 series V100R001C20, T series V200R002C20, or OceanStor V3 series V300R001C10 or later, you need to use the password of the machine-machine user.

n If remote devices are OceanStor

18000 series V100R001C10, T series V200R002C10, or OceanStor V3 series V300R001C00 or earlier, you need to use the password of the super administrator or administrator account on the older version remote device.

[Value]

n The default

password of the machinemachine user is

mm_user@stor age.

NOTE

You are advised to change your login password periodically in the future by executing the

change mm_user password

command. This reduces the password leakage risks. For details about how to use the command, see the Command Reference of the corresponding product model.

n The password of

the super administrator or administrator account is consistent with the password on the remote device.

TCP/IP Port

Ethernet port number on the remote storage device.

l Adding a Fibre Channel link

a. Set Link Type to FC.

b. In the Fibre Channel link list, select a Fibre Channel link.

c. Set parameters for the Fibre Channel link. Table 3-2 lists related parameters.

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3260

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Table 3-2 Fibre Channel link parameters

Parameter Description Setting

3 Configuring Remote Replication

Username The user used for communication

authentication between remote devices.

n If remote devices are OceanStor

18000 series V100R001C20, T series V200R002C20, or OceanStor V3 series V300R001C10 or later, you need to use the machine-machine user.

n If remote devices are OceanStor

18000 series V100R001C10, T series V200R002C10, or OceanStor V3 series V300R001C00 or earlier, you need to use the super administrator or administrator account on the older version remote device.

[Value]

n The default

username of the machinemachine user is mm_user.

n Obtain the super

administrator or administrator account on the remote device.

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Parameter Description Setting

3 Configuring Remote Replication

Password Password of the user used for

communication authentication between remote devices.

n If remote devices are OceanStor

18000 series V100R001C20, T series V200R002C20, or OceanStor V3 series V300R001C10 or later, you need to use the password of the machine-machine user.

n If remote devices are OceanStor

[Value]

n The default

password of the machinemachine user is

mm_user@stor age.

NOTE

You are advised to change your login password periodically in the future by executing the

change mm_user password

command. This reduces the password leakage risks. For details about how to use the command, see the Command Reference of the corresponding product model.

n The password of

the super administrator or administrator account is consistent with the password on the remote device.

Step 6 Click Next. The information summary is displayed.

Step 7 Click Finish. The operation result is displayed. Perform the following operations based on the

number of links you want to add:

l To add only one link, click Close.

l To add another link for link redundancy, select Continue adding links and click Close.

The Add Link dialog box is displayed. Perform Step 8 as prompted.

NOTE

After the links are added, you can select the remote device from the remote device list. On the navigation bar, click Add Link or right-click the device and choose Add Link to add other links.

Step 8 Optional: Perform the following operations based on Link Type:

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l Add an iSCSI link.

a. In the Link Type drop-down list, select iSCSI.

b. In the Local Device area, set Controller and Local Port.

c. In the Remote Device area, set IP Address.

d. Click OK.

The Execution Result dialog box is displayed indicating that the operation succeeded.

e. Click Close.

l Add a Fibre Channel link.

a. In the Link Type drop-down list, select FC.

b. Select the newly added Fibre Channel link and click OK.

The Execution Result dialog box is displayed indicating that the operation succeeded.

c. Click Close.

3 Configuring Remote Replication

----End

Follow-up Procedure

If error code 1073804034 occurs or the connection fails to be created, see the case What Can I Do If the Remote Connection Fails to Be Created with the TOE Interface Module in FAQ.

After an iSCSI replication link is established, run change iscsi target and change initiator on the primary and secondary end (For details about how to use these commands, see the Command Reference of the corresponding product model.) to enable CHAP authentication for the iSCSI replication link. If CHAP authentication is not enabled, spoofing may occur between primary and secondary storage systems.

In the synchronous remote replication, if the distance between the local and remote storage devices exceeds 25 km, you can run the following command to enable the fast write function to ensure link transfer efficiency.

l FC link:

By default, this function is disabled. This function is only enabled for 4-port 8 Gbit/s Fibre Channel links. You can run the change port fc fc_port_id=XXX fast_write_enable=yes command to enable the fast write function. To obtain the value of fc_port_id, run show port general. The function needs to be enabled on both the local and remote storage system. Run the show port general port_id=XXX command. When the status of Fast Write Enable in the output is Yes, this function is successfully enabled.

l iSCSI link:

By default, this function is enabled. You are advised to enable this function. You can run the change remote_device link link_type=iSCSI link_id=XXX fast_write_enable=no command to disabled the fast write function. To obtain the value of link_id, run show remote_device link. The function needs to be enabled only on the local storage system. You can run the show remote_device link link_type=iSCSI link_id=XXX command to query the status of this function. When the status of Fast Write Enable in the output is Yes, this function is successfully enabled.

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3 Configuring Remote Replication

3.6 Creating a Remote Replication

3.6.1 Creating a Synchronous Remote Replication (Applicable to V300R006C00)

Creating a synchronous remote replication includes the following operations: configuring basic information about the remote replication, selecting a primary resource and a secondary resource, and setting remote replication properties. You can proceed as prompted.

Prerequisites

l The remote replication license is valid.

l The local and remote storage devices must support remote replication.

l The remote storage device is added already, and secondary resource is created on the

remote device.

l The storage capacities of primary and secondary LUNs are the same.

l The statuses of primary and secondary LUNs are healthy.

l The primary and secondary LUNs have not configured any feature that conflicts with the

remote replication feature.

Procedure

Step 1 Log in to DeviceManager.

Step 2 Choose

Step 3 Click Create.

Step 4 Select the replication mode of the remote replication to Synchronous, and click Next.

Step 5 Select the primary resource and secondary resource to form a remote replication pair.

Data Protection > Remote Replication.

The Create Remote Replication Pair dialog box is displayed.

1. Select a primary resource type from the drop-down list.

Possible values of the primary resource type are LUN, Microsoft Exchange, VMware, Hyper-V, Oracle and SQL Server.

2. Optional: When Microsoft Exchange, VMware, Hyper-V, Oracle or SQL Server is selected as the primary resource type, click Select, select an application instance, and click OK.

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NOTE

When you create a remote replication task using the storage resources created based on an application, all available LUNs of the application are displayed in Primary Resource. For details about how to create storage resources based on applications, see Creating Storage Resources Based on Applications in the OceanStor V3 Series V300R006 Basic Storage Service Guide for Block. For OceanStor 2000 V3 series (excluding 2600 V3 Video Surveillance Edition and 2800 V3), 5000 V3 series, and 6000 V3 series, you can configure the storage resources created based on applications. For OceanStor 18000 V3 series, the storage resources created based on applications are not displayed when you create a remote replication pair, because this type of storage resources is not supported by OceanStor 18000 V3 series.

3. In the primary resource area, select the desired primary resource.

4. From the Remote device drop-down list, select the remote device where the secondary resource resides.

NOTE

If no remote device exists, click Add to add one.

5. In the secondary resource area, select the desired secondary resource.

6. Click Add to Pairs.

Add the pair of the primary and secondary resources to Pairs.

7. Click Next.

3 Configuring Remote Replication

Step 6 Set properties of the synchronous remote replication.

1. From the Speed drop-down list, select the desired speed for synchronizing data from the primary resource to the secondary resource.

– Low: When the speed is set to low, remote replication will take a long time. This

value is applicable to scenarios where the service load is heavy. The speed is normally from 0 to 5 MB/s.

– Medium: When the speed is set to medium, remote replication will take a relatively

short period. This value is applicable to scenarios where the service load is heavy. The speed is normally from 10 to 20 MB/s. (default value)

– High: When the speed is set to high, remote replication will take a short period.

This value is applicable to scenarios where the service load is relatively light. The speed is normally from 50 to 70 MB/s.

– Highest: When the speed is set to highest, remote replication will be complete in

the shortest period. This value is applicable to scenarios where the service load is light. The speed is normally above 100 MB/s.

2. In Recovery policy drop-down list, select whether the remote replication pair automatically synchronizes data or not after internal I/O errors of a remote replication task are rectified or the replication link is up.

– Manual: The pair enters the To be recovered state. You need to manually

synchronize the data from the primary resource to the secondary resource in the pair.

– Automatic: The pair enters the Synchronizing state. The system will automatically

synchronize the data from the primary resource to the secondary resource in the pair. (default value)

3. Select the initial synchronization method of the remote replication.

– Data is inconsistent between the primary and secondary resources. After a

remote replication task is created, the system automatically performs data synchronization.: After the remote replication task is created, the data on the

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secondary resource is overwritten immediately. Ensure that the data on the secondary resource is no longer necessary or has been backed up. (default value)

– Data is inconsistent between the primary and secondary resources. After a

remote replication task is created, manually perform data synchronization.:

After the remote replication task is created, manually synchronize data on the primary and secondary resources as soon as possible to ensure data consistency.

– The data on primary and secondary resources is consistent and data

synchronization is not required.: Ensure that the data on the primary and

secondary resources is consistent. If the data is inconsistent, the secondary resource cannot be used to recover data or take over services from the primary resource when the primary resource fails. As a result, data loss and service interruption may occur.

4. Optional: Select Set the I/O timeout threshold for the secondary LUN and set Timeout Threshold (second).

NOTE

If the data is not written into the secondary LUN successfully after the timeout you set, the remote replication pair enters the Interrupted status.

The value range of timeout is 10 to 30 seconds. The default value is 30 seconds.

5. Click Next.

3 Configuring Remote Replication

Step 7 Optional: Add the remote replication pair to a newly created consistency group.

1. Select Create a consistency group and add pairs to it.

2. Set Name and Description of the consistency group.

3. Click Next.

NOTE

You cannot set Timeout Threshold (second) when creating consistency groups. After the remote replication is added to a consistency group, it inherits the configuration of the consistency group.

Step 8 Confirm the creation of the remote replication pair.

1. Click Next and view the configuration summary of the remote replication pair.

2. Click Finish to create the remote replication pair.

The security alert dialog box is displayed.

3. Confirm the information in the dialog box. Select I have read and understand the consequences associated with performing this operation. and click OK.

The Execution Result dialog box is displayed, indicating that the operation succeeded.

4. Click Close.

----End

3.6.2 Creating a Synchronous Remote Replication (Applicable to V300R006C10)

Prerequisites

l The remote replication license is valid.

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l The local and remote storage devices must support remote replication.

l The remote storage device is added already, and secondary resource is created on the

remote device.

l The storage capacities of primary and secondary LUNs are the same.

l The statuses of primary and secondary LUNs are healthy.

l The primary and secondary LUNs have not configured any feature that conflicts with the

remote replication feature.

Procedure

Step 1 Log in to DeviceManager.

3 Configuring Remote Replication

Step 2 Choose

Data Protection > Remote Replication > Remote Replication Pair.

Step 3 Click Create.

The Create Remote Replication Pair dialog box is displayed.

Step 4 Specify the replication mode and resource type for remote replication.

1. Set Replication Mode to Synchronous.

2. Select a primary resource type from the drop-down list.

Possible values of the primary resource type are LUN, Microsoft Exchange, VMware, Hyper-V, Oracle and SQL Server.

3. Optional: When Microsoft Exchange, VMware, Hyper-V, Oracle or SQL Server is selected as the primary resource type, click Select, select an application instance, and click OK.

NOTE

4. Click Next.

Step 5 Select synchronous remote replication primary and secondary resources.

1. From the Remote device drop-down list, select the remote device where the secondary resource resides.

NOTE

If no remote device exists, click Add to add one.

2. In the Primary Resource area, select the remote replication primary resource.

3. In the Secondary Resource area, select the remote replication secondary resource.

4. Click Add to Pairs.

The selected primary and secondary resources are added to Pairs.

5. Click Next.

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Step 6 Set properties of the synchronous remote replication.

1. In the Set Properties dialog box, set synchronous remote replication parameters.

Table 3-3 describes the related parameters.

Table 3-3 Synchronous remote replication pair parameters

Parameter Description Value

3 Configuring Remote Replication

Speed Speed of data synchronization. The

value can be: – Low: When the speed is set to low,

remote replication will take a long time. This value is applicable to scenarios where the service load is heavy. The speed is normally from 0 to 5 MB/s.

– Medium: When the speed is set to

medium, remote replication will take a relatively short period. This value is applicable to scenarios where the service load is heavy. The speed is normally from 10 to 20 MB/s. (default value)

– High: When the speed is set to high,

remote replication will take a short period. This value is applicable to scenarios where the service load is relatively light. The speed is normally from 50 to 70 MB/s.

– Highest: When the speed is set to

highest, remote replication will be complete in the shortest period. This value is applicable to scenarios where the service load is light. The speed is normally above 100 MB/s.

[Default value]

Medium

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Parameter Description Value

3 Configuring Remote Replication

Recovery Policy After the remote replication internal I/O

error is rectified or the replication link is up, the remote replication pair automatically synchronizes data or not. The values include:

– Manual: The pair enters the To be

recovered state. You need to

manually synchronize the data from the primary resource to the secondary resource in the pair.

– Automatic: The pair enters the

Synchronizing state. The system

will automatically synchronize the data from the primary resource to the secondary resource in the pair. (default value)

[Default value]

Automatic

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Parameter Description Value

3 Configuring Remote Replication

Initial Synchronization

This parameter refers to the mode of initial data synchronization between the primary and secondary resources. The value can be:

– Data is inconsistent between the

primary and secondary resources. After a remote replication task is created, the system automatically performs data synchronization.:

After the remote replication task is created, the data on the secondary resource is overwritten immediately. Ensure that the data on the secondary resource is no longer necessary or has been backed up. (default value)

– Data is inconsistent between the

primary and secondary resources. After a remote replication task is created, manually perform data synchronization.: After the remote

replication task is created, manually synchronize data on the primary and secondary resources as soon as possible to ensure data consistency.

– The data on primary and

secondary resources is consistent and data synchronization is not required.: Ensure that the data on

the primary and secondary resources is consistent. If the data is inconsistent, the secondary resource cannot be used to recover data or take over services from the primary resource when the primary resource fails. As a result, data loss and service interruption may occur.

[Default value]

Data is inconsistent between the primary and secondary resources. After a remote replication task is created, the system automatically performs data synchronization.

Set the I/O timeout threshold for the secondary LUN

If the data is not written into the secondary LUN successfully after the timeout you set, the remote replication pair enters the Interrupted status.

Timeout Threshold (second)

Timeout threshold that data is not written to the secondary LUN successfully.

2. Click Next.

Step 7 Optional: Add the remote replication pair to a newly created consistency group.

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[Default value]

Disable

[Default value]

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NOTE

If Initial Synchronization is set to The data on primary and secondary resources is consistent and data synchronization is not required, the Add Pairs to Remote Replication Consistency Group page will be

skipped.

1. Select Create a consistency group and add pairs to it.

2. Set Name and Description of the consistency group.

3. Click Next.

NOTE

You cannot set Timeout Threshold (second) when creating consistency groups. After the remote replication is added to a consistency group, it inherits the configuration of the consistency group.

Step 8 Confirm the creation of the remote replication pair.

1. View the configuration summary of the remote replication pair.

2. Click Finish to create the remote replication pair.

The security alert dialog box is displayed.

3. Confirm the information in the dialog box. Select I have read and understand the consequences associated with performing this operation. and click OK.

The Execution Result dialog box is displayed, indicating that the operation succeeded.

4. Click Close.

3 Configuring Remote Replication

----End

3.6.3 Creating an Asynchronous Remote Replication (Applicable to V300R006C00)

Creating an asynchronous remote replication includes the following operations: configuring basic information about the remote replication, selecting a primary resource and a secondary resource, and setting remote replication properties. You can proceed as prompted.

Prerequisites

l The remote replication license is valid.

l The local and remote storage devices must support remote replication.

l The remote storage device is added already, and secondary LUN is created on the remote

device.

l The storage capacities of primary and secondary LUNs are the same.

l The statuses of primary and secondary LUNs are healthy.

l The primary and secondary LUNs have not configured any feature that conflicts with the

remote replication feature.

Procedure

Step 1 Log in to DeviceManager.

Step 2 Choose

Data Protection > Remote Replication.

Step 3 Click Create.

The Create Remote Replication Pair Wizard dialog box is displayed.

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Step 4 On the Select Replication Mode page, select Asynchronous. Click Next.

Step 5 Select the primary resource and secondary resource to form a remote replication pair.

1. Select a primary resource type from the drop-down list.

Possible values of the primary resource type are LUN, Microsoft Exchange, VMware, Hyper-V, Oracle and SQL Server.

2. Optional: When Microsoft Exchange, VMware, Hyper-V, Oracle or SQL Server is selected as the primary resource type, click Select, select an application instance, and click OK.

NOTE

3. In the Secondary Resource area, select a remote device to which the primary resource is copied from the Remote Device drop-down list.

4. In the Secondary Resource area, select the secondary resource.

5. Click Add to Pairs. After the pair is added successfully, the specified pair will be displayed in Pairs.

3 Configuring Remote Replication

NOTE

The Remote Device Compression Status in the pairs list indicates that the compression algorithm or protocol of both local and remote storage devices matches or not. If it matches, the status displays as Valid, indicating data compression transmission is available. Otherwise, the status displays as Invalid, indicating data compression transmission is not available.

6. Click Next.

The Set Properties page is displayed.

Step 6 Set properties of the remote replication pair.

1. On the Set Properties page, set the remote replication parameters based on your service requirements.

Table 3-4 describes parameters of remote replication.

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Table 3-4 Parameters of remote replication

Parameter Description Value

3 Configuring Remote Replication

Speed Speed of data synchronization. The values

include: – Low: When the speed is set to low,

remote replication will take a long time. This value is applicable to scenarios where the service load is heavy. The speed is normally from 0 to 5 MB/s.

– Medium: When the speed is set to

medium, remote replication will take relatively short period. This value is applicable to scenarios where the service load is heavy. The speed is normally from 10 to 20 MB/s.

– High: When the speed is set to high,

remote replication will take a short period. This value is applicable to scenarios where the service load is relatively light. The speed is normally from 50 to 70 MB/s.

– Highest: When the speed is set to

highest, remote replication will be complete in the shortest period. This value is applicable to scenarios where the service load is light. The speed is normally above 100 MB/s.

[Default value]

Medium

Recovery Policy After the remote replication internal I/O

error is rectified or the replication link is up, the remote replication pair automatically synchronizes data or not. The values include:

– Manual: The pair enters the To be

recovered state. You need to manually

synchronize the data from the primary resource to the secondary resource in the pair.

– Automatic: The pair enters the

Synchronizing state. The system will

automatically synchronize the data from the primary resource to the secondary resource in the pair.

[Default value]

Automatic

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Parameter Description Value

3 Configuring Remote Replication

Data Transmission

Synchronization Method

During primary and secondary resource synchronization, data is compressed or not. If you select data compression transmission, replication links are with lower bandwidth pressure, while improving the replication performance. The values include:

– Compression – No compression

NOTE

When Remote Device Compression Status is Invalid, do not configure Data Transmission

as Compression, or creating a remote replication pair would fail.

Mode of data synchronization between the primary resource and secondary resource. The values include:

– Manual: Data must be manually

synchronized between the primary resource and secondary resource.

– Timed wait when synchronization

begins: The system starts timing as

soon as the latest synchronization begins. When the time specified in Interval has elapsed, the system automatically starts to synchronize data between the primary resource and secondary resource again.

NOTE

If the latest synchronization is still being executed after the time specified in Interval has elapsed, the data synchronization will start after the latest synchronization finishes.

– Timed wait when synchronization

ends: The system starts timing as soon

as the latest synchronization ends. When the time specified in Interval has elapsed, the system automatically starts to synchronize data between the primary resource and secondary resource again.

[Default value]

No compression

[Default value]

Manual

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Parameter Description Value

3 Configuring Remote Replication

Interval Time spent waiting of the two

synchronization methods, Timed wait

when synchronization begins and Timed wait when synchronization ends.

NOTE

This parameter is available when Replication Mode is set to Asynchronous and Synchronization Method is set to Timed wait when synchronization begins or Timed wait when synchronization ends.

[Value range] – The interval is

an integer ranging from 1 to 1440 (inclusive), when minutes is used as the unit.

– The interval is

an integer ranging from 3 to 59 (inclusive), when seconds is used as the unit.

[Default value]

If the unit is minute, the default value is 60 minutes.

If the unit is second, the default value is 30 seconds.

NOTE

When the primaryend model is 2200 V3, the resource type is LUN, the unit can only be minutes and the interval is an integer ranging from 15 to 1440 (inclusive).

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Parameter Description Value

3 Configuring Remote Replication

Initial Synchronization

Mode of initial data synchronization between the primary resource and secondary resource. The values include:

– Data is inconsistent between the

primary and secondary resources. After a remote replication task is created, the system automatically performs data synchronization.:

– Data is inconsistent between the

primary and secondary resources. After a remote replication task is created, manually perform data synchronization.: After the remote

replication task is created, manually synchronize data on the primary and secondary resources as soon as possible to ensure data consistency.

– The data on primary and secondary

resources is consistent and data synchronization is not required.:

Ensure that the data on the primary and secondary resources is consistent. If the data is inconsistent, the secondary resource cannot be used to recover data or take over services from the primary resource when the primary resource fails. As a result, data loss and service interruption may occur.

[Default value]

Data is inconsistent between the primary and secondary resources. After a remote replication task is created, the system automatically performs data synchronization.

2. Click Next.

The Add Pairs to Remote Replication Consistency Group page is displayed.

Step 7 Optional: Add the remote replication pair to a newly created consistency group.

1. Select Create a consistency group and add pairs to it.

2. Set the Name and Description of consistency group.

3. Click Next.

The Summary page is displayed.

Step 8 Confirm the creation of the remote replication pair.

1. Check the remote replication pair information. If correct, click Finish.

The security alert dialog box is displayed.

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2. Read the content in the dialog box carefully, and select I have read and understood the consequences associated with performing this operation..

3. Click OK.

The Execution Result page is displayed.

4. On Execution Result page, check whether remote replication pair is created successfully.

5. Click Close.

The remote replication pair displays detailed information in the remote replication pair list if successfully created.

----End

3 Configuring Remote Replication

3.6.4 Creating an Asynchronous Remote Replication (Applicable to V300R006C10)

Prerequisites

Procedure

Step 1 Log in to DeviceManager.

Step 2 Choose

Step 3 Click Create.

Step 4 Specify the replication mode and resource type for remote replication.

l The remote replication license is valid.

l The local and remote storage devices must support remote replication.

l The remote storage device is added already, and secondary LUN is created on the remote

device.

l The storage capacities of primary and secondary LUNs are the same.

l The statuses of primary and secondary LUNs are healthy.

l The primary and secondary LUNs have not configured any feature that conflicts with the

remote replication feature.

Data Protection > Remote Replication > Remote Replication Pair.

The Create Remote Replication Pair dialog box is displayed.

1. Set Replication Mode to Synchronous.

2. Select a primary resource type from the drop-down list.

Possible values of the primary resource type are LUN, Microsoft Exchange, VMware, Hyper-V, Oracle and SQL Server.

3. Optional: When Microsoft Exchange, VMware, Hyper-V, Oracle or SQL Server is selected as the primary resource type, click Select, select an application instance, and click OK.

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NOTE

4. Click Next.

Step 5 Select synchronous remote replication primary and secondary resources.

1. From the Remote device drop-down list, select the remote device where the secondary resource resides.

NOTE

If no remote device exists, click Add to add one.

2. In the Primary Resource area, select the remote replication primary resource.

3. In the Secondary Resource area, select the remote replication secondary resource.

4. Click Add to Pairs.

The selected primary and secondary resources are added to Pairs.

5. Click Next.

3 Configuring Remote Replication

Step 6 Set properties of the remote replication pair.

1. On the Set Properties page, set the remote replication parameters based on your service requirements.

Table 3-5 describes parameters of remote replication.

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Table 3-5 Parameters of remote replication

Parameter Description Value

3 Configuring Remote Replication

Speed Speed of data synchronization. The values

include: – Low: When the speed is set to low,

remote replication will take a long time. This value is applicable to scenarios where the service load is heavy. The speed is normally from 0 to 5 MB/s.

– Medium: When the speed is set to

medium, remote replication will take relatively short period. This value is applicable to scenarios where the service load is heavy. The speed is normally from 10 to 20 MB/s.

– High: When the speed is set to high,

remote replication will take a short period. This value is applicable to scenarios where the service load is relatively light. The speed is normally from 50 to 70 MB/s.

– Highest: When the speed is set to

highest, remote replication will be complete in the shortest period. This value is applicable to scenarios where the service load is light. The speed is normally above 100 MB/s.

[Default value]

Medium

Recovery Policy After the remote replication internal I/O

error is rectified or the replication link is up, the remote replication pair automatically synchronizes data or not. The values include:

– Manual: The pair enters the To be

recovered state. You need to manually

synchronize the data from the primary resource to the secondary resource in the pair.

– Automatic: The pair enters the

Synchronizing state. The system will

automatically synchronize the data from the primary resource to the secondary resource in the pair.

[Default value]

Automatic

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Parameter Description Value

3 Configuring Remote Replication

Data Transmission

Synchronization Method

– Compression – No compression

NOTE

When Remote Device Compression Status is Invalid, do not configure Data Transmission

as Compression, or creating a remote replication pair would fail.

Mode of data synchronization between the primary resource and secondary resource. The values include:

– Manual: Data must be manually

synchronized between the primary resource and secondary resource.

– Timed wait when synchronization

begins: The system starts timing as

NOTE

If the latest synchronization is still being executed after the time specified in Interval has elapsed, the data synchronization will start after the latest synchronization finishes.

– Timed wait when synchronization

ends: The system starts timing as soon

as the latest synchronization ends. When the time specified in Interval has elapsed, the system automatically starts to synchronize data between the primary resource and secondary resource again.

[Default value]

No compression

[Default value]

Manual

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Parameter Description Value

3 Configuring Remote Replication

Interval Time spent waiting of the two

synchronization methods, Timed wait

when synchronization begins and Timed wait when synchronization ends.

NOTE

This parameter is available when Replication Mode is set to Asynchronous and Synchronization Method is set to Timed wait when synchronization begins or Timed wait when synchronization ends.

[Value range] – The interval is

an integer ranging from 1 to 1440 (inclusive), when minutes is used as the unit.

– The interval is

an integer ranging from 3 to 59 (inclusive), when seconds is used as the unit.

[Default value]

If the unit is minute, the default value is 60 minutes.

If the unit is second, the default value is 30 seconds.

NOTE

When the primaryend model is 2200 V3, the resource type is LUN, the unit can only be minutes and the interval is an integer ranging from 15 to 1440 (inclusive).

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Parameter Description Value

3 Configuring Remote Replication

Initial Synchronization

Mode of initial data synchronization between the primary resource and secondary resource. The values include:

– Data is inconsistent between the

primary and secondary resources. After a remote replication task is created, the system automatically performs data synchronization.:

– Data is inconsistent between the

primary and secondary resources. After a remote replication task is created, manually perform data synchronization.: After the remote

replication task is created, manually synchronize data on the primary and secondary resources as soon as possible to ensure data consistency.

– The data on primary and secondary

resources is consistent and data synchronization is not required.:

[Default value]

Data is inconsistent between the primary and secondary resources. After a remote replication task is created, the system automatically performs data synchronization.

2. Click Next.

The Add Pairs to Remote Replication Consistency Group page is displayed.

Step 7 Optional: Add the remote replication pair to a newly created consistency group.

NOTE

skipped.

1. Select Create a consistency group and add pairs to it.

2. Set the Name and Description of consistency group.

3. Click Next.

The Summary page is displayed.

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Step 8 Confirm the creation of the remote replication pair.

1. Check the remote replication pair information. If correct, click Finish.

The security alert dialog box is displayed.

2. Read the content in the dialog box carefully, and select I have read and understood the consequences associated with performing this operation..

3. Click OK.

The Execution Result page is displayed.

4. On Execution Result page, check whether remote replication pair is created successfully.

5. Click Close.

The remote replication pair displays detailed information in the remote replication pair list if successfully created.

----End

3.7 Creating a Consistency Group

3 Configuring Remote Replication

Prerequisites

Precautions

Remote replication can implement data backup and disaster recovery in the scenario where a host writes data to a single or multiple independent primary LUNs. However, remote replication cannot implement data backup and disaster recovery in the scenario where a host writes data to multiple dependent primary LUNs. A consistency group ensures data consistency of secondary LUNs of all remote replication pairs in the group at the same point in time (for example, the data of all secondary LUNs are the data copy of its primary LUN at 3:00 PM today), therefore ensures the data availability of primary LUNs after disaster recovery.

l The Role of the remote replication pair to be added into the consistency group must be

Primary.

l The remote replication pair to be added into the consistency group must be from the

same storage device.

l The Replication Mode of the remote replication pair to be added into the consistency

group must be the same as the Replication Mode of the consistency group.

l If the remote replication pair is not in split status, the system will split the remote

replication pair first and then add it into the consistency group.

l The consistency group does not support the remote replication pair whose resource type

is file system.

l After the remote replication pair has been added into the consistency group, the remote

replication pair will function according to the replication properties of the consistency group (the properties are Recovery Policy, Speed, Data Transmission, Synchronization Method, and Interval). Functions of the remote replication pair are not relevant to its own properties.

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Procedure

Step 1 Log in to DeviceManager.

Step 2 Choose Data Protection > Remote Replication > Remote Replication

Consistency Group.

Step 3 Click Create.

The Create Consistency Group Wizard dialog box is displayed.

Step 4 Configure basic information about the consistency group. The Table 3-6 describes related

parameters.

Table 3-6 Consistency Group Parameters

3 Configuring Remote Replication

Parameter

Description Setting

Name The name of the consistency group. [Value range]

l The name must be

unique.

l The name can

contain letters, digits, periods (.), underscores (_), and hyphens (-).

l The name contains

1 to 31 characters.

[Example]

ConsistentGroup001

Description The description of the consistency group. None

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Parameter Description Setting

3 Configuring Remote Replication

Replication Mode Data replication mode of a consistency

group. The values include:

l Synchronous: When data is written on

a primary resource, the write request is also sent to the secondary resource. Only after the data is written on both the primary and secondary resources successfully, does the host receive a successful data write message. Synchronous mode ensures that the data on the primary resource and secondary resource synchronizes in real-time. If the primary resource is written successfully, a write success acknowledgement is returned to the host.

l Asynchronous: When data is written

on a primary resource successfully, the host receives a successful data write message. In the meanwhile, the primary site records the data difference between the written data and the secondary resource. In the data synchronization later, only the different data the primary site records are synchronized to the secondary site, reducing the write latency of application server to the minimum.

[Default value]

Asynchronous

Recovery Policy After the remote replication internal I/O

error is rectified or the replication link is up, the consistency group automatically synchronizes data or not. The values include:

l Manual: The consistency group enters

the To be recovered state. You need to manually synchronize the data from the primary resource to the secondary resource.

l Automatic: The consistency group

enters the Synchronizing state. The system will automatically synchronize the data from the primary resource to the secondary resource.

[Default value]

Automatic

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Parameter Description Setting

3 Configuring Remote Replication

Speed Rate of data synchronization of the

consistency group. The values include:

l Low: When the speed is set to low,

remote replication will take a long time. This value is applicable to scenarios where the service load is heavy. The speed is normally from 0 to 5 MB/s.

l Medium: When the speed is set to

medium, remote replication will take relatively short period. This value is applicable to scenarios where the service load is heavy. The speed is normally from 10 to 20 MB/s.

l High: When the speed is set to high,

remote replication will take a short period. This value is applicable to scenarios where the service load is relatively light. The speed is normally from 50 to 70 MB/s.

l Highest: When the speed is set to

highest, remote replication will be complete in the shortest period. This value is applicable to scenarios where the service load is light. The speed is normally above 100 MB/s.

[Default value]

Medium

Data Transmission During data synchronization for the

consistency group, data is compressed or not. If you select data compression transmission, replication links are with lower bandwidth pressure, while improving the replication performance. The values include:

l Compression

l No compression

NOTE

This parameter is available only when Replication Mode is set to Asynchronous.

[Default value]

No compression

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Parameter Description Setting

3 Configuring Remote Replication

Synchronization Method

Mode of data synchronization of the consistency group. The values include:

l Manual: Synchronization is performed

manually.

l Timed wait after synchronization

begins: The system starts timing as

NOTE

If the latest synchronization is still being executed after the time specified in Interval has elapsed, the data synchronization will start after the latest synchronization finishes.

l Timed wait after synchronization

ends: The system starts timing as soon

as a synchronization ends. When the time specified in Interval has elapsed, the system starts to synchronize data again.

NOTE

This parameter is available only when Replication Mode is set to Asynchronous.

[Default value]

Manual

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Parameter Description Setting

3 Configuring Remote Replication

Interval Waiting time for the two synchronization

methods, Timed wait after

synchronization begins and Timed wait after synchronization ends.

NOTE

This parameter is available only when

Synchronization Method is set to Timed wait after synchronization begins or Timed wait after synchronization ends.

[Value range]

l An integer ranging

from 1 to 1440 (inclusive), when minutes is used as the unit.

l An integer ranging

from 3 to 59 (inclusive), when seconds is used as the unit.

[Default value]

60, when minutes is used as the unit.

30, when seconds is used as the unit.

NOTE

When the primary-end model is 2200 V3, the unit can only be minutes and the interval is an integer ranging from 15 to 1440 (inclusive).

Step 5 Select the remote replication pair that you want to add to the consistency group.

1. Click Next, and in Owning Remote Device of Secondary Resource of Pair, select the remote device.

NOTE

The remote device is the storage device which the secondary resource of the remote replication pair to be added into the consistency group belongs to.

2. From the Available Remote Replication Pairs list, select one or multiple remote

replication pairs and click

to add.

Step 6 Confirm the consistency group creation.

1. Click Next and view the configuration summary of the consistency group to be created.

2. Click Finish to create the consistency group.

The security alert dialog box is displayed.

3. Read the content in the dialog box carefully, and select I have read and understand the consequences associated with performing this operation..

4. Click OK.

The Execution Result page is displayed.

5. On Execution Result page, check whether the consistency group is created successfully.

6. Click Close.

----End

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3.8 Verifying the Configuration

Remote Replication Pair

l The primary and secondary storage systems of the remote replication task are correctly

connected to the application server.

l Initial synchronization of the remote replication task has been complete.

Step 1 Map the primary and secondary LUNs to the host.

1. Log in to DeviceManager. Choose Provisioning > LUN > LUN Group. Click Create to create LUN groups and add the primary and secondary LUNs of the remote replication task to corresponding LUN groups.

3 Configuring Remote Replication

Choose Provisioning > Mapping View. Choose the mapping view that the host group which holds the application servers belongs to. Then add the newly created LUN group to this mapping view.

NOTE

To check on a standby server whether data replication succeeds, you need to mount the secondary LUN to the standby server. Before mounting the secondary LUN, split the LUN and set Status of Secondary Resource Protection to Read/Write.

Step 2 Check whether data replication succeeded.

1. Log in to the application server at the primary site and write file X.txt to the primary LUN. When Pair Running Status is Normal, go to the next step.

2. Log in to DeviceManager at the primary site. Choose Data Protection > Remote Replication > Remote Replication Pair. Click the remote replication to be synchronized. Choose More > Synchronize to perform the synchronization manually.

3. Log in to the standby server at the secondary site to check whether data file X.txt exists on the secondary LUN.

– If yes, data replication succeeded.

– If no, log in to DeviceManager at the primary site. Choose

Remote Replication > Remote Replication Pair. Click the remote replication task to be synchronized. Choose More > Synchronize to perform the synchronization manually.

Data Protection >

Step 3 Check whether a primary/secondary switchover can be performed on the secondary site.

1. Log in to DeviceManager at the secondary site. Choose Data Protection > Remote Replication > Remote Replication Pair and perform the following operations.

a. Select the remote replication pair to be split and choose More > Split.

b. Click Properties. Modify Status of secondary resource protection to Read/Write

to set the secondary LUN to readable and writable.

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c. Choose More > Primary/Secondary Switchover to switch the secondary LUN to

the primary LUN.

2. Log in to the standby server at the secondary site and write file Y.txt to the new primary LUN. Check whether the primary LUN is readable and writable.

– If yes, a primary/secondary switchover can be performed on the secondary site. – If no, a primary/secondary switchover cannot be performed on the secondary site.

Check whether an alarm about remote replication exists on DeviceManager at the primary and secondary sites. If yes, solve the fault based on the alarm information and repeat the previous operations. If no, contact technical support engineers.

Step 4 Check whether data can be recovered.

1. Log in to DeviceManager at the secondary site, choose Data Protection > Remote Replication > Remote Replication Pair, and perform the following operations.

a. Select the remote replication for which you want to enable secondary resource

protection and click Properties. Modify Status of secondary resource protection to Read-only to set the secondary LUN to read-only.

b. Choose More > Synchronize to perform the synchronization manually.

2. After the synchronization is complete, log in to the application server at the primary site to check whether file Y.txt exists on the secondary LUN (after the primary/secondary switchover).

– If yes, data can be recovered. – If no, data cannot be recovered. Check whether an alarm about remote replication

exists on DeviceManager at the primary and secondary sites. If yes, solve the fault based on the alarm information and repeat the previous operations. If no, contact technical support engineers.

3. Switch services back to the primary site after the verification. Log in to DeviceManager at the primary site, choose Data Protection > Remote Replication > Remote Replication Pair, and perform the following operations.

3 Configuring Remote Replication

a. Select the remote replication pair to be split and choose More > Split.

b. Click Properties. Modify Status of secondary resource protection to Read/Write

to set the secondary LUN to readable and writable.

c. Choose More > Primary/Secondary Switchover.

d. Click Properties. Modify Status of secondary resource protection to Read-only

to set the secondary LUN to read-only.

e. Choose More > Synchronize to perform the synchronization manually.

----End

Remote Replication Consistency Group

l The primary and secondary storage systems of a remote replication task are correctly

connected to the application server.

l Initial synchronization for the consistency group is complete.

l Remote replication pairs have been created and added to the consistency group.

NOTE

After remote replication pairs are added to a consistency group, you can only perform operations on the consistency group and cannot perform operations on the pairs in the consistency group.

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Step 1 Map all the primary and secondary LUNs in the consistency group to the host.

1. Log in to DeviceManager. Choose Provisioning > LUN > LUN Group. Click Create to create LUN groups and add the primary and secondary LUNs of the remote replication task to corresponding LUN groups.

3 Configuring Remote Replication

2. Choose

Provisioning > Mapping View. Choose the mapping view that the host group which holds the application servers belongs to. Then add the newly created LUN group to this mapping view.

NOTE

Step 2 Check whether data replication succeeded.

1. Log in to the application server at the primary site and write file X1.txt to all primary LUNs of the consistency group. When Running Status of the consistency group is Normal, go to the next step.

2. Log in to DeviceManager at the primary site. Choose Data Protection > Remote Replication > Remote Replication Consistency Group. Click the remote replication to be synchronized. Choose More > Synchronize to perform the synchronization manually.

3. Log in to the standby server at the secondary site to check whether data file X1.txt exists on the secondary LUNs of the consistency group.

– If yes, data replication succeeded. – If no, log in to DeviceManager at the primary site. Choose Data Protection >

Remote Replication > Remote Replication Consistency Group. Click the consistency group to be synchronized. Choose More > Synchronize to perform the synchronization manually.

Step 3 Check whether a primary/secondary switchover can be performed on the secondary site.

1. Log in to DeviceManager at the secondary site, choose Data Protection > Remote Replication > Remote Replication Consistency Group, and perform the following operations.

a. Right-click the consistency group to be split and choose More > Split.

b. Right-click the consistency group for which you want to disable secondary resource

protection. Choose More > Disable Protection for Secondary Resource to set secondary LUNs of all remote replication pairs in the consistency group to readable and writable.

c. Right-click the consistency group for which you want to perform a primary/

secondary switchover. Choose More > Primary/Secondary Switchover to switch secondary LUNs of all remote replication pairs in the consistency group to primary LUNs.

2. Log in to the standby server at the secondary site and write file Y1.txt to the new primary LUNs. Check whether the primary LUNs are readable and writable.

– If yes, a primary/secondary switchover can be performed on the secondary site. – If no, a primary/secondary switchover cannot be performed on the secondary site.

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Step 4 Check whether data can be recovered.

1. Log in to DeviceManager at the secondary site. In the navigation tree, choose Data Protection > Remote Replication > Remote Replication Consistency Group and perform the following operations:

a. Right-click the consistency group for which you want to enable secondary resource

protection. Choose More > Enable Protection for Secondary Resource to set secondary LUNs of all remote replication pairs in the consistency group to readonly.

b. Right-click the remote replication task to be synchronized. Choose More >

Synchronize to perform the synchronization manually.

2. After the synchronization is complete, log in to the application server at the primary site to check whether file Y1.txt exists on the secondary LUNs (after the primary/secondary switchover).

– If yes, data can be recovered. – If no, data cannot be recovered. Check whether an alarm about remote replication

exists on DeviceManager at the primary and secondary sites. If yes, solve the fault based on the alarm information and repeat the previous operations. If no, contact technical support engineers.

3 Configuring Remote Replication

a. Click the consistency group to be split and choose More > Split.

b. Choose More > Disable Protection for Secondary Resource to set secondary

LUNs of all remote replication pairs in the consistency group to readable and writable.

c. Choose More > Primary/Secondary Switchover to switch secondary LUNs of all

remote replication pairs in the consistency group to primary LUNs.

d. Choose More > Enable Protection for Secondary Resource to set secondary

LUNs of all remote replication pairs in the consistency group to read-only.

e. Click the consistency group to be synchronized. Choose More > Synchronize to

perform the synchronization manually.

----End

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About This Chapter

The remote replication feature is usually used for remote disaster recovery. The feature can be configured flexibly based on customer requirements. This chapter provides an example to explain how to configure the remote replication feature in a typical remote disaster recovery scenario. The content is divided into requirement analysis, configuration planning, configuration procedure, and configuration verification.

4 Configuration Example

4.1 Central Backup and Disaster Recovery

This example explains how to configure the remote replication feature to implement central backup and disaster recovery.

4.1 Central Backup and Disaster Recovery

This example explains how to configure the remote replication feature to implement central backup and disaster recovery.

4.1.1 Requirement Analysis

This section analyzes the requirements of a carrier that implements central backup and disaster recovery using the remote replication feature and comes to a conclusion.

Requirement Source

A carrier has a service site at site A. At site A, there is an application server that serves the user data management application. Data generated by the application server is stored in an OceanStor storage system. The data and bandwidth status of site A is as follows:

l The daily data change amount is between 100 MB to 200 MB.

l The total data amount does not exceed 500 GB.

l The current network bandwidth between the application server and the storage system is

2 Mbit/s.

Since the network is complete and the application is running properly, the carrier prefers to keep the existing network. Figure 4-1 shows a diagram of the existing network.

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Figure 4-1 Diagram of the existing network

4 Configuration Example

Site A

Switch

Host port P0 on

controller A

Management

network port

Maintenance

terminal

Application server 1

Host port P0 on

controller B

Storage system

Table 4-1 and Table 4-2 describe the LUN mapping and IP address allocation on existing

devices at site A.

Table 4-1 LUN mapping at site A

LUN Name

LUN Size Host Mapping

LUN001 500 GB Mapped to application server 1

Table 4-2 IP address allocation at site A

Port

Management network

IP Address Subnet Mask Gateway

192.168.15.60 255.255.0.0 192.168.0.1

port

Host port P0 on

172.16.19.30 255.255.0.0 172.16.0.1

controller A

Host port P0 on

172.16.19.31 255.255.0.0 172.16.0.1

controller B

The carrier wants to protect service data at site A against natural disasters and quickly recover the service data when a disaster occurs. The specific requirements are as follows:

l Data backup and disaster recovery

Data at site A is automatically backed up to a backup site without interrupting services to minimize data loss upon a disaster. The backup data can be used to quickly recover services at site A after the disaster.

l Quick service recovery

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Once a disaster happens, site B takes over services with an RTO no longer than 15 minutes.

l Central data management

After a new service site (site C) or more service sites are set up, data from all service sites is backed up to the backup site for central management, reducing deployment and maintenance costs.

l Data analysis and mining

Service data can be exported for analysis and mining to support policy-making.

Requirement Analysis and Conclusions

The previous requirements indicate that the carrier needs a disaster recovery solution. Table

4-3 lists the criteria for implementing a remote disaster recovery solution.

Table 4-3 Criteria for implementing a remote disaster recovery solution

4 Configuration Example

Consideration

Description

Data transfer amount Inter-city data transfer is subject to the bandwidth. The amount

of lost data decreases as the amount of data transferred within a specified period of time increases.

Host performance Data backup affects services on the host. Services on the host

can run properly if the impact of backup on the services is minor.

Data availability Availability of data at the disaster recovery site is significant

for data recovery. Therefore, data at the disaster recovery site must be available any time.

Service continuity The disaster recovery site must be able to quickly take over

services at the service site through a service switchover to protect service continuity.

Others Other factors to be considered include cost as well as central

data management and analysis.

The details of the solution are as follows:

l Data transfer amount

At site A, the daily data change amount is between 100 MB to 200 MB, while the available bandwidth is only 2 Mbit/s, which is not adequate for the data change amount. Therefore, the data replication period must be shortened to reduce the amount of data transferred each time.

l Host performance

The carrier requires minimized impact of backup on host performance to ensure host services run correctly. Multiple service sites may locate in different places and are comparatively far from the backup site. Therefore, asynchronous remote replication is suitable for this case. Table 4-4 describes advantages of asynchronous remote replication.

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Table 4-4 Advantages of an asynchronous remote replication solution

Advantage Description

4 Configuration Example

Incremental data replication

No host performance deterioration

Quick service takeover When a disaster occurs, remote replication pairs are

l Data availability

The carrier needs to analyze the backup data and requires that data at site A be quickly recovered after a disaster. Therefore, data at the backup site must be available anytime.

l Service continuity

The backup site must be able to quickly take over services when a disaster causes a failure of site A to minimize the loss, by setting the Interval to 10 minutes to satisfy the RPO requirement.

l Others

Besides backup and disaster recovery, the carrier hopes backup data be managed centrally and latest data at service sites be available anytime so that services can be analyzed conveniently. Therefore, data at service sites needs to be centrally backed up to one site. In this way, copies of all data can be quickly obtained when necessary.

Incremental data replication is implemented between the primary and secondary storage systems. Specifically, after the initial synchronization (full replication), only data changes are replicated from the service site to the backup site during each synchronization process. Since the amount of data replicated each time is small, synchronization is fast.

Data replication is between storage systems, occupying no host resources, so it does not affect current services. The quality of service (QoS) does not decrease.

interrupted between the service site and the backup site. The backup site quickly takes over services of the service site.

Based on the former analysis, the details of the solution are as follows:

l Choose the central disaster backup solution and build a central backup site at site B

(equipment at the backup site includes an OceanStor storage system, an application server, a maintenance terminal, and an iSCSI switch).

l Use asynchronous remote replication for disaster backup.

l Set up an iSCSI connection between sites A and B.

4.1.2 Configuration Planning

This section describes how to plan the remote replication feature for central backup and disaster recovery. This section is organized into two parts: network planning and service planning.

Network Planning

Figure 4-2 shows a diagram of the planned network. As shown in the diagram, central backup

and disaster recovery is implemented without changing the carrier's existing network.

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Figure 4-2 Diagram of central backup and disaster recovery

4 Configuration Example

Site A

Switch

Management

network port

Maintenance

terminal

Application

Controller A host port P0

storage system

server 1

Controller B host port P0

Primary

Standby

server

Controller A host port P0

Secondary

storage system

Site C

Site B

Switch

Controller B host port P0

Management

network port

Maintenance

terminal

To achieve data backup to the central backup site, an iSCSI connection between site A and site B must be set up first, and then a logical connection needs to be established by adding a route and a target. Before setting up the connections, a detailed networking plan must be drawn.

Table 4-5 describes the IP address plan for site B.

Table 4-5 IP address plan for site B

Port

Management network port

Host port P0 on controller A

Host port P0 on controller B

Service Planning

Based on the conclusion of the requirement analysis, a central disaster backup solution can meet the requirements of the carrier. Figure 4-3 shows the configuration roadmap of the solution.

IP Address Subnet Mask Gateway

192.168.19.10 255.255.0.0 192.168.0.1

172.17.20.31 255.255.0.0 172.17.0.1

172.17.20.32 255.255.0.0 172.17.0.1

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Figure 4-3 Configuration roadmap

Enable the remote replication feature.

Start

Check the license files.

Create a disk domain.

4 Configuration Example

Make sure that the license files of storage systems at sites A and B grant the permission for asynchronous remote replication.

Create a secondary LUN in the storage system at site B.

Set up a logical connection between sites A and B.

Create an asynchronous remote replication session in the primary storage system at site A.

Create a storage pool.

Create a secondary LUN.

Configure host port IP

addresses.

Add routes.

Add a remote device.

Create an asynchronous

remote replication session.

End

In the storage system at site B, create a secondary LUN of the same size as the primary LUN at site A.

If you want to connect the two storage systems at the two sites through iSCSI host ports and the host ports of the two storage systems are in different network segments, add a route for each storage system.

After a logical connection is set up between the two storage systems, create an asynchronous remote replication session in the storage system at site A.

Table 4-6 lists the configuration operations and planning items involved in the configuration

example.

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Note:

Mandatory Optional

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Table 4-6 Configuration operations and planning items

4 Configuration Example

Configuration Roadmap

Enable the remote replication feature

Create a secondary LUN in the storage system at site B.

Major Operation and Purpose

Check the license file.

Check the license file to ensure that it grants the permission to use the remote replication feature.

Create a disk domain.

Before creating a storage pool, a disk domain needs to be created. All the disks used to create a storage pool are in the disk domain.

Planning

Parameter Planned Value

Item

None None None

Disk domain's name and disk type

l Name

l Disk Type

l DiskDomain_

l Performance

Tier (SAS)

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4 Configuration Example

Configuration Roadmap

Major Operation and Purpose

Create a storage pool.

This step is fundamental for subsequent storage space configuration. A storage pool is a container in which multiple LUNs can be created.

NOTE

When configuring asynchronous remote replication, reserve certain space in the storage pool of the secondary storage array to ensure that sufficient space is provided for COW for host I/Os or data synchronizati on I/Os of the secondary storage array during remote replication.

Planning Item

Storage pool parameters and available disk domains for the storage system at site B

Parameter Planned Value

l Name

l Disk Domain

l RAID policy

l StoragePool_

l DiskDomain_

l Capacity

l RAID 5;4D

+1P

l 1TB

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4 Configuration Example

Configuration Roadmap

Set up a logical connection between sites A and B.

Major Operation and Purpose

Create a secondary LUN.

Storage pools cannot be identified by hosts. The host can use the storage space only when the storage space of the storage pool is divided into LUNs.

Configure host port IP addresses.

This step is fundamental for setting up a logical connection between the two storage systems.

Planning Item

Information about the secondary LUN in the storage system at site B

IP addresses of host port at site A and that at site B

Parameter Planned Value

l Name

l Capacity

l Quantity

l Owning

Storage Pool

l IPv4

Address

l Subnet Mask

l LUN_BK

l 500GB

l 1

l StoragePool_

l Site A

– 172.16.19.

– 255.255.0.

l Site B

– 172.17.20.

– 255.255.0.

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4 Configuration Example

Configuration Roadmap

Major Operation and Purpose

Add a route.

Planning Item

Information about the route list of site A and that of site B

Parameter Planned Value

l Type

l Destination

address

l Destination

mask

l Gateway

l Site A

– Network

segment route

– 172.17.0.0 – 255.255.0.

– 172.16.0.1

l Site B

– Network

segment route

– 172.16.0.0 – 255.255.0.

– 172.17.0.1

Add a remote device.

Set up a logical connection between the primary and secondary storage systems for remote data transmission.

NOTE

You only need to perform this step on either storage system.

Remote device information of the storage system at site A or site B

l Link type

l Controller

l Port

l IP address

l Username

l Password

l iSCSI

l CTE0.A

l CTE0.R5.IO

M0.P0

l 172.17.20.31

l The right

username

l The right

password

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4 Configuration Example

Configuration Roadmap

Major Operation

Planning Item

Parameter Planned Value

and Purpose

Create an asynchronous remote replication session in the primary storage system at site A.

Create an asynchronous remote replication session.

The created asynchronous remote replication session is used to implement remote data replication.

Basic information and the primary LUN of the remote replication session in the primary storage system at site A

l Select

Replication Model

l Select

Primary LUN

l Secondary

LUN

l Rate

l Recovery

policy

l Data

Transmission

l Asynchronou

l LUN001

l LUN_BK

l Medium

l Automatic

l No

compression

l Timed wait

when synchronizati on begins

l 10 (minutes)

l Synchronizat

ion type

l Interval

a: The user used for communication authentication between remote devices.

l If remote devices are OceanStor 18000 series V1R1C20, T series V2R2C20, or

OceanStor V3 series V3R1C10 or later, you need to use the machine-machine user. The default username and password of the machine-machine user are mm_user and mm_user@storage respectively.

NOTE

You are advised to change your login password periodically in the future by executing the change mm_user password command. This reduces the password leakage risks. For details on using the

command, see the Command Reference of the corresponding product model.

l If remote devices are OceanStor 18000 series V1R1C10, T series V2R2C10, or

OceanStor V3 series V3R1C00 or earlier, you need to use the super administrator or administrator account on an earlier version of a remote device. The username and password of the super administrator or administrator account are consistent with those on the remote device.

NOTE

l Keep the default values of the parameters that are not mentioned in this table.

l If the version of the local device is different from that of the remote device, you need to add a

remote device on the newer version device. Otherwise the operation may fail.

4.1.3 Configuration Operations

After completing the network and service plans, configure the remote replication feature on the DeviceManager according to the plans.

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Prerequisites

l The connection between the storage system and application server at each site is normal.

l The iSCSI connection between the primary storage system at site A and the secondary

storage system at site B is normal.

Precaution

The OceanStor 5000 V3 series is used as an example. For other product models, the operations are similar but the GUI display may be different. The actual GUI depends on the specific product model.

Procedure

Step 1 Check the license file.

Remote replication is a value-added feature. Before configuring this feature, you must make sure that the license file of the storage system grants the permission for the remote replication feature.

4 Configuration Example

On the navigation bar of DeviceManager of each storage system, click License Management. On the Active License tab page, check information about the license file for remote replication. If the license file does not grant the permission for remote replication, search for License in Help. Then follow the displayed instructions to import and activate the license file.

Step 2 Create a secondary LUN in the secondary storage system at site B.

1. Create a disk domain in the secondary storage system at site B.

On the navigation bar of DeviceManager, click

Configuration and Optimization area, click Disk Domain to create DiskDomain_BK.

Provisioning. On the Storage

Settings. Click

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4 Configuration Example

2. Create a storage pool in the secondary storage system at site B.

This step is fundamental for subsequent storage space configuration. A storage pool is a container, in which multiple LUNs can be created.

On the navigation bar of DeviceManager, click

Provisioning. On the Storage

Configuration and Optimization area, click Storage Pool to create StoragePool_BK.

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4 Configuration Example

3. Create the secondary LUN in the storage pool.

A storage pool cannot be identified by hosts. The host can use the storage space only when the storage space of the storage pool is divided into LUNs.

On the navigation bar of the DeviceManager, click Block Storage Service area, click LUN to create a secondary LUN. The secondary LUN must have the same capacity as the primary LUN (500 GB). Otherwise the system cannot detect the created secondary LUN when you are adding a secondary LUN.

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4 Configuration Example

Step 3 Set up a logical connection between sites A and B.

1. Configure host port IP addresses.

This step is fundamental for setting up a logical connection between the two storage systems. The following uses port CTE0.R5.IOM0.P0 on the primary storage system at site A as an example to describe how to configure a port IP address. The procedure for any other host port on either site is the same.

In the navigation tree, click

Provisioning. Click Port, and click the host port whose IP address you want to change. Click Properties. On the Properties of the Port dialog box, configure the IP address of the port.

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4 Configuration Example

2. Add routes for iSCSI host ports of both the primary and secondary storage systems.

Perform this step when the host port on the primary storage system and that on the secondary storage system use IP addresses in different network segments. If the host ports use IP addresses in the same network segment, skip this step. The following uses the primary storage system at site A as an example to describe how to add a route for a host port. The procedure at site B is the same.

After modifying host port IP address, in Ethernet Ports, select the host port for which you need to add routes. Click Route Management, and choose Add in the displayed dialog box to add route information.

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3. Add a remote device in either the primary storage system at site A or the secondary storage system at site B.

4 Configuration Example

Add a remote device at one side to establish a usable link between two storage systems. The following uses the primary storage system at site A as an example to describe how to add a remote device. The procedure for the secondary storage system at site B is the same.

On the navigation bar of DeviceManager, click

Data Protection and then Remote Device. Choose Add Remote Device to add a remote device following the Add Remote Device Wizard dialog box.

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4 Configuration Example

NOTE

– If remote devices are OceanStor 18000 series V1R1C20, T series V2R2C20, or OceanStor

V3 series V3R1C10 or later, you need to use the machine-machine user. The default username and password of the machine-machine user are mm_user and mm_user@storage respectively.

NOTE

You are advised to change your login password periodically in the future by executing the change mm_user password command. This reduces the password leakage risks. For details on using the command, see the Command Reference of the corresponding product model.

– If remote devices are OceanStor 18000 series V1R1C10, T series V2R2C10, or OceanStor

V3 series V3R1C00 or earlier, you need to use the password of the super administrator or administrator account on the older version remote device. The username and password of the super administrator or administrator account are consistent with those on the remote device.

4. Add an iSCSI link.

Only one link is selected between the storage systems when a remote device is added. To ensure link redundancy, you must manually add links after the remote device is added.

Select the added remote device and click Add Link. Set Link Type to iSCSI and then add desired links.

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4 Configuration Example

Step 4 Create an asynchronous remote replication.

On the navigation bar of DeviceManager, click

Replication. Choose Create to create RP_001 following the Create Remote Replication Wizard dialog box.

Data Protection and then Remote

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4 Configuration Example

The following shows the properties of the asynchronous remote replication.

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4 Configuration Example

----End

4.1.4 Configuration Verification

After configuring the remote replication feature, view the data status of the secondary LUN of the remote replication session to check whether data replication from the primary LUN to the secondary LUN succeeded.

Prerequisites

l The connection between the storage system and application server at site A and that at

site B are normal.

l Initial synchronization of the asynchronous remote replication session is complete.

Procedure

Step 1 Map the primary and secondary LUNs to the hosts.

1. Log in to DeviceManager, and choose Create to create LUN groups. Then add primary and secondary LUNs to corresponding LUN groups.

Provisioning > LUN > LUN Group. Click

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Huawei OceanStor 2200 V3, OceanStor 2600 V3 Video Surveillance Edition, OceanStor 5600 V3, OceanStor 5800 V3, OceanStor 6800 V3 Features Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

About This Document

Contents

1 Feature Description

1.1 Overview

1.2 License Requirements and Compatible Products

1.3 Principles

1.3.1 Related Concepts

1.3.2 Data Replication

1.3.3 Service Switchover

1.3.4 Data Recovery

1.3.5 Functions of a Consistency Group

1.4 Impact and Restrictions

1.5 Application Scenarios

2 Planning

3 Configuring Remote Replication

3.1 Configuration Process

3.2 Preparing for the Configuration

3.3 Checking the License File

3.4 (Optional) Adding Routes

3.5 Adding a Remote Device

3.6 Creating a Remote Replication

3.6.1 Creating a Synchronous Remote Replication (Applicable to V300R006C00)

3.6.2 Creating a Synchronous Remote Replication (Applicable to V300R006C10)

3.6.3 Creating an Asynchronous Remote Replication (Applicable to V300R006C00)

3.6.4 Creating an Asynchronous Remote Replication (Applicable to V300R006C10)

3.7 Creating a Consistency Group

3.8 Verifying the Configuration

4 Configuration Example

4.1 Central Backup and Disaster Recovery

4.1.1 Requirement Analysis

4.1.2 Configuration Planning

4.1.3 Configuration Operations

4.1.4 Configuration Verification