Service Migration in the Production Center After Fault Recovery

Prerequisites

• LUN-based protection policies and recovery plans have been configured for other applications.
• For protected groups that use asynchronous remote replication, the DR center has at least one copy of intact service data.

Context

If data or applications become unavailable due to disasters or faults in the production center, services will be quickly switched to and started in the DR center. After the production center recovers, the services will be switched back to it by performing planned migration.

Procedure

1. Perform pre-recovery configurations.
2. Perform a fault recovery.
   

   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.

   1. On the menu bar, select Utilization > Data Restore.
   2. Select the recovery plan to be recovered and click More > Fault Recovery on the Operation list.
   3. Perform fault recovery based on protected object types.
      • 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 Fault Recovery.
        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.
      • If the type of protected objects is NAS File System, perform the following operations: 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. Then click OK.
   • Latest data: The system uses service backup data backed up to the DR center before the disaster for recovery and starts services in the DR center.
   • Latest snapshots: Before a manual or automatic protected group execution, the system automatically creates a snapshot for placeholder VMs of the DR site. If you choose this mode for fault recovery, the system will use the latest snapshot of the placeholder VMs to register and start VMs.

3. In the production center, check the application startup status.

   After the fault recovery 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, you need to log in to the application host in the disaster recovery 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.

4. Check the environment before starting reprotection.
   

   For Huawei Distributed Block Storage, you need to repair the production end. After it is repaired, manually unmap the LUNs on the production end.

5. Perform reprotection to protect services switched to the DR center.

   After the planned migration is complete, the application system is working in the DR center and protected groups become Invalid. You must perform reprotection to recover the replication status and synchronize the data from the DR center to the production center. Then, the original DR center becomes the new 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.