Reconstructing a DR System by Using the Remote DR Center (Cascading Network)

Prerequisites

• Storage arrays have been configured in the production center and same-city DR center, and LUNs have been created.
• Physical and logical links have been established between the production center and the same-city DR center and between the same-city DR center and the remote DR center.
• The DR management network has been recovered between the production center and the same-city DR center.

Procedure

1. Log in to the storage array in the remote DR center. Create an asynchronous remote replication relationship between the storage arrays in the remote DR center and same-city DR center.
2. Synchronize service data from the remote DR center to the same-city DR center.
   1. Log in to the DR host in the remote DR center, shut shown the application, and unmount disks.
   2. Log in to the storage array in the remote DR center, and remove the mapping view between the DR host and LUNs.
   3. Perform data synchronization for consistency groups of asynchronous remote replication.

3. Split the asynchronous remote replication relationship between the storage arrays in the remote DR center and same-city DR center.
   1. Log in to the storage array in the remote DR center.
   2. Split consistency groups of asynchronous remote replication.
   3. Select Enable Protection for Secondary Resource for consistency groups of asynchronous remote replication.

4. Perform a primary/secondary switchover for consistency groups of asynchronous remote replication.
   1. Log in to the storage array in the remote DR center.
   2. Perform a primary/secondary switchover for consistency groups of asynchronous remote replication.

      The storage array in the remote DR center becomes the secondary storage array, and the storage array in the same-city DR center becomes the primary storage array.

   3. Log in to the storage array in the same-city DR center. Perform data synchronization for consistency groups of asynchronous remote replication.

      The same-city DR center has been reconstructed by using the remote DR center.

5. Log in to the storage array in the same-city DR center. Create a synchronous remote replication relationship between the storage arrays in the same-city DR center and production center, and perform data synchronization for consistency groups of synchronous remote replication.

   Data has been synchronized to the production center.

6. Log in to the storage array in the production center. Perform a primary/secondary switchover for consistency groups of synchronous remote replication.

   Data has been synchronized and remote replication relationships have been restored between the production center, same-city DR center, and remote DR center.

7. Test services.
   1. Log in to the storage array in the production center, and re-create a mapping view between the production host and LUNs.
   2. Log in to the production host, mount disks, and start the application to test services.

8. Restore DR configurations.
   1. Log in to the DR management server eReplication in the same-city DR center. Add the hosts and storage arrays in the production center and same-city DR center to the corresponding sites.
   2. Delete the existing protected groups and recovery plans.
   3. Re-create protected groups and recovery plans.

Result

• Data is synchronously replicated from the production center to the same-city DR center and is asynchronously replicated from the same-city DR center to the remote DR center.
• protected groups and recovery plans are re-created on the DR management servers. You can see a complete DR topology and perform DR testing.