Planned Migration from the Production Center to the Same-City DR Center

Prerequisites

• The production and same-city DR centers communicate with each other properly. The management system and the DR environment in the same-city DR center are working normally.
• Recovery plans for services to be migrated have been created on eReplication, which have succeeded in at least one test.
  

  If no DR test is performed before the planned migration, the migration has a higher rate to fail. A migration failure will interrupt DR services. For this reason, at least one recovery plan test must be executed successfully before the planned migration.

• If the information about storage devices, hosts, or VMs is modified at the production or DR site, manually refresh the information. For details, see Refreshing Resource Information.
• In a DR Star network, before performing planned migration, log in to DeviceManager and ensure that the running status of the DR Star network is Enabled.

Procedure

1. Perform pre-migration configurations.
   • When the protected objects are databases, pre-migration configurations can be performed in the following two modes.
     • Method one: Manually stop applications and delete mapping views.
       1. Manually stop the service system and database applications and uninstall disks on the production host.
       2. Delete LUN mappings (to application hosts at the production sites) from the storage array in the production center.
       3. Log in to eReplication at the DR site, click Resources, select the site and the storage device, and refresh the storage device status, to ensure that all LUN mappings are removed.
     • Method two: Edit planned migration procedures. Before the planned migration, applications on hosts are automatically stopped and mapping views are automatically deleted.
       1. Log in to eReplication at the DR site, and on the menu bar select On the menu bar, select Utilization > Data Restore.
       2. Select the recovery plan and click the Procedure tab.
       3. Click Edit.
       4. From the drop-down list, select Planned Migration.
       5. Click Stop production service and click Start the step.
       6. Click Apply.

2. Perform the planned migration to migrate services from the production center to the same-city DR center.
   1. On the menu bar, select Utilization > Data Restore.
   2. Select the recovery plan used to perform the planned migration and click More > Planned Migration on the Operation list.
   3. Perform the planned migration based on different types of protected objects.
      

      If Huawei UltraPath has been installed on the Linux-based DR host, ensure that I/O suspension time is not 0 and all virtual devices generated by UltraPath have corresponding physical devices. For details, see the OceanStor UltraPath for Linux xxx User Guide.

   • If the type of protected objects is LUN perform the following operations:
     1. Select DR Site.
     2. Select Host (Group) > Available DR Hosts or Host Groups (This operation is optional when the protected object type is LUN).
        

        • If the storage array used at the DR site is T series V2 or later, the to-be-recovered host selected by a user can belong to only one host group on the storage array, and the host group can belong to only one mapping view. Moreover, the storage LUN used by protected applications and its corresponding secondary remote replication LUNs must belong to one LUN group, and the LUN group must reside in the same mapping view as the host group. If the storage array version is T series V2R2, deselect Enable Inband Command to change the mapping view attribute after the mapping view is created.
        • If the storage array is T series V2R2 or later, or 18000 series, automatic host adding and storage mapping are provided. Ensure that the storage is connected to hosts' initiators properly. In this manner, the system can automatically create hosts, host groups, LUN groups, and mapping views on the storage. The creation principles are as follows:

          

        • If no DR host or DR host group is selected, you need to manually map DR LUNs to the DR host when the type of protected objects is LUN.
     3. Click Planned Migration.
     4. In the Warning dialog box that is displayed, read the content of the dialog box carefully and select I have read and understood the consequences associated with performing this operation.
     5. Click OK.

3. After the migration is complete, verify that applications are started and data is consistent in the DR center.

   After the planned migration is complete, check whether the applications and data are normal. If an application or data encounters an exception, contact Huawei technical support.

   • Note the following when checking the startup status of applications.
   • If the protection policies are based on applications, check whether the applications are started successfully and data can be read and written correctly.
   • If the protection policies are based on LUNs, log in to the application host in the DR center, scan for disks, and start applications. Then check whether the applications are started successfully and data can be read and written correctly.
     

     You can use self-developed scripts to scan for disks, start applications, and test applications.

   • You can check data consistency by viewing the last entry of data written to the production and DR centers. If the last entry of data written to the production and DR centers is the same, the data consistency is ensured.

4. Delete data after migration.

   If storage array-based remote replication DR is used, snapshots are created automatically on the storage array at the DR site to back up DR data during the planned migration. If snapshots are not automatically deleted after the planned migration is complete, manually delete them to release storage space.

   

   • A snapshot name is a string of 31 characters named in the following format: DRdata_LUNID_YYYYMMDDHHMMSS_BAK, where YYYYMMDDHHMMSS is the backup time and LUNID may be the snapshot ID (a number ranging from 1 to 65535). This naming format enables you to quickly find the snapshots that you want to delete from the storage array at the DR site.
   • When the protection type is SAP HANA, you do not need to clear the data after the planned migration is complete.

5. Check the environment before starting the reprotection.
6. Perform reprotection to protect services switched to the intra-city DR center.

   After you complete the planned migration, the service system is working in the intra-city DR center and protected groups become Invalid. You must perform reprotection to restore data replication from the intra-city DR center to the production center so that data can be synchronized back to the production center.

   

   To ensure the normal running of protected groups and recovery plans after reprotection, the system automatically clears protected and recovered configurations, including startup configurations of protection policies and recovery plans, self-defined execution scripts, and self-defined execution steps. In addition, re-configuration of protection and recovery policies is recommended to ensure the continuity of DR services.

   1. On the menu bar, select Utilization > Data Restore.
   2. Select the recovery plan and click More > Reprotection on the Operation list.
   3. Carefully read the content of the Confirm dialog box that is displayed and click OK to confirm the information.
      

      If Save user configuration data is selected, self-defined protection policies and recovery settings, such as self-defined recovery steps, will be retained. Ensure that the configuration data has no adverse impact on service running after reprotection.

Result

After the reprotection is complete, the status of protected groups returns to normal and the network mode of the Geo-Redundant Solution switches between cascading and parallel. A cascading network will change to a parallel one in geo-redundant protection mode and vice versa.