After a remote replication relationship is established between the production center and the DR center, initial synchronization is automatically started to replicate data from the production center to the DR center.

In actual application scenarios, the amount of data in the production center is large (up to a terabyte level), but the data transmission bandwidth is limited between the DR center and the production center. As a result, initial synchronization takes a long time. Performing initial synchronization using an external storage system can greatly reduce the initial synchronization time.

Figure A-1 shows the process for using the external storage system to perform initial synchronization for remote replication.

Figure A-1 Process for using an external storage system to perform initial synchronization

The process in Figure A-1 is as follows:

1. Replicate data from the production center to the external storage system.
2. Move the external storage system to the DR center.
3. Replicate data from the external storage system to the storage system in the DR center.
4. Start remote replication from the production center to the DR center.

Methods for performing initial synchronization for remote replication using the external storage system vary with providers of the LUN copy feature:

• Method 1: Use the snapshot feature of the production center and the LUN copy feature of the production and DR centers and create LUN copies in the production center and the DR center respectively.
• Method 2: Use the snapshot feature of the production center and the LUN copy feature of the external storage system and create LUN copies on the external storage system.