Creating a Remote Replication Pair

This operation enables you to create a remote replication pair between a local namespace and a remote namespace, so that data in the local namespace can be synchronized to the remote namespace. When a disaster occurs, you can use the data in the remote namespace to reconstruct data in the local namespace. Alternatively, you can directly take over services from the remote namespace to minimize data loss and shorten service interruption time.

Prerequisites

When creating a remote replication pair, ensure that the secondary namespace has not been used (data, snapshots, quotas, or dtrees are not created in the secondary namespace) and the DPC function of the secondary namespace is disabled. Otherwise, the remote replication pair cannot be created.

Procedure

Choose Data Protection > Protection Entity > Namespace > Remote Replication Pair.
Select the desired account from the Account drop-down list in the upper left corner.
Click Create.
The Create Remote Replication Pair dialog box is displayed.
In the Available Namespaces area on the left, select one or more desired namespaces for which you want to create remote replication pairs and they are added to the Selected Namespaces area on the right.

Namespaces for which the cross-site DR feature has been configured cannot be used to create a remote replication pair.
Click Next.
From the Remote Device drop-down list, select the remote device with which you want to create a remote replication pair.
Configure remote replication pairs.
1. Click Configure.
  The Configure Pair page is displayed.
2. Configure remote replication pairs.
  1. In the Local Resources area, select the local namespace.
  2. In the Remote Resources area, select the remote namespace. The name of the remote namespace must be the same as that of the local namespace.
  3. Click Add to Pair. After the pair is added successfully, the pair will be displayed in the list below.
  4. After all local resources are configured as pairs, click OK.

Set properties of a remote replication pair. Table 1 describes related parameters.

**Table 1** Remote replication pair parameters
Parameter	Description
Sync Type	Determines how data is synchronized between primary and secondary resources. Possible values are: Manual: Data must be manually synchronized between primary and secondary resources. Timed wait after sync 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 primary and secondary resources again. NOTE: If the latest synchronization is still being executed after the time specified in Interval has elapsed, data synchronization will start after the latest synchronization finishes. Timed wait after sync ends: The system starts timing after the last synchronization finishes. After the time specified in Interval is reached, the system automatically starts data synchronization between primary and secondary resources again. Specific time policy: The system automatically synchronizes data between primary and secondary resources based on a specific time policy.
Interval	Synchronization interval for Timed wait after sync begins and Timed wait after sync ends. [Value range] The interval is an integer ranging from 1 to 1440 when minutes is used as the unit. The value is an integer ranging from 30 to 59 when seconds is used as the unit. NOTE: This parameter is available only when Sync Type is set to Timed wait after sync begins or Timed wait after sync ends.
Time Policy	Specific time policy: The system automatically synchronizes data between primary and secondary resources based on a specific time policy. [Value range] Weekly: Data synchronization begins at a specific time on a specific day. Its value ranges from 00:00 on Monday to 23:59 on Sunday. Daily: Data synchronization begins on every day. Its value ranges from 00:00 to 23:59. Hourly: Data synchronization begins in every hour. Its value is an integer ranging from 0 to 59. NOTE: This parameter is available only when Sync Type is set to Specific time policy.

Set the advanced properties of a remote replication pair.

Select Advanced in the upper right corner.

Configure advanced remote replication pair properties. Table 2 describes related parameters.

**Table 2** Advanced remote replication pair parameters
Parameter	Description
Speed	Indicates the data synchronization speed of the remote replication pair. The value ranges from 1 MB/s to 10,240 MB/s (or 1024 KB/s to 10,485,760 KB/s). During initial synchronization, the recommended rate is 100 MB/s or higher. During incremental synchronization, if the service is busy, the recommended rate is 0 MB/s to 20 MB/s. During incremental synchronization, if the service load is heavy, the recommended rate is 20 MB/s to 70 MB/s. During incremental synchronization, if the service is idle, the recommended rate is 100 MB/s or higher. The default value is 32 MB/s.
Recovery Policy	Determines how data is synchronized after an internal I/O error or a replication link fault is rectified. The default value is Automatic. [Value range] Automatic: The system automatically synchronizes data. The pair enters the Synchronizing state. Manual: Data must be synchronized manually. The pair enters the To be recovered state.
Initial Sync	Indicates the initial synchronization mode of local and remote resources. The default value is Automatic. [Value range] Automatic: The system automatically synchronizes data of the primary resource to the secondary resource upon pair creation. Ensure that data of the secondary resource is no longer needed or has been backed up. Manual: Data of the primary resource must be manually synchronized to the secondary resource. For details, see Synchronizing a Remote Replication Pair.

Click Next.
A summary is displayed.
Confirm information about the created remote replication pair and click OK.
Confirm your operation as prompted.