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    Cloud Backup:Step 7: Perform a failover

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    Cloud Backup:Step 7: Perform a failover

    Last Updated:Jun 12, 2026

    After the replication status of a protection group changes to incremental replication, you can perform a failover. This topic describes the basic operations of failover and failback.

    Failover types

    • Switch After Data Synchronization

      During the failover, Cloud Backup stops the protected instances in the protection group, and performs the final data synchronization after all the protected instances are stopped. The failover starts after the data is synchronized. This ensures that the data at the disaster recovery site is the same as that at the production site. This type of failover applies to scenarios such as planned disaster recovery drills and business migration.

    • Switch Now

      During the failover, Cloud Backup attempts to stop the protected instances in the protection group. Cloud Backup does not wait until all the protected instances are stopped or perform the final data synchronization. Some data may be lost within the recovery point objective (RPO) range. This type of failover applies to scenarios in which a fault cannot be rectified within a short period of time at the production site and business must be immediately switched to the disaster recovery site.

    Failback types

    • Switch After Data Synchronization

      During the failback, Cloud Backup stops the protected instances in the protection group, and performs the final data synchronization after all the protected instances are stopped. The failback starts after the data is synchronized. The service unavailability time is longer than the time for the immediate failback. The production site works properly in such failback scenarios.

    • Switch Now

      During the failback, Cloud Backup attempts to stop the protected instances in the protection group. Cloud Backup does not wait until all the protected instances are stopped or perform the final data synchronization. This type of failback applies to scenarios where a fault cannot be rectified within a short period of time at the disaster recovery site and business must be immediately switched to the production site. During the failback, some data may be lost.

    Switch After Data Synchronization

    Forward Protection - Failover

    Perform the following steps to perform a failover:

    1. Log on to the Cloud Backup console.

    2. In the navigation pane on the left, choose Disaster Recovery > ECS Disaster Recovery.

    3. If you are not on the EBS Async Replication page, click Switch to EBS Async Replication.

    4. On the Site Pairs tab, click the target site pair, and then click the Protection Group tab.

    5. On the Protection Group tab, find the target protection group. In the Actions column, click image..png and choose Forward Protection > Failover.

    6. In the Start Failover dialog box, select Switch after data synchronization, configure the policy for handling an insufficient instance specification, and then click OK.

      Note

      • An instance in economical mode may fail to start due to insufficient instance specifications in the zone. In this case, select Upgrade within specification family. Cloud Backup then preferentially attempts to upgrade the instance within the specification family. The maximum CPU or memory size is three times that of the current instance specification.

      • If the automatic configuration upgrade fails or you select manual processing, modify the instance specifications in the ECS console based on the error message, and then retry the task in the task list.

      1. The protection group status changes to Failover in Progress.

      2. After the failover is complete, the protection group status changes to Failover Succeeded.

    7. After the failover is complete, click Manage Protected Instances for the protection group to open the Protected Instances page.

    8. Click the link in the ID/Name of instance at DR site column to verify the data and applications on the ECS instance.

    9. After verification, in the Actions column for the protection group, click image..png and choose Forward Protection > Failover Completed.

      The protection group status changes to Failover Confirmed. At this point, the ECS instance at the production site is Stopped, and the ECS instance at the disaster recovery site is Running.

    Enable Reverse Replication

    Reverse replication is the process of replicating data from the disaster recovery site to the production site for failback.

    1. Log on to the Cloud Backup console.

    2. In the navigation pane on the left, choose Disaster Recovery > ECS Disaster Recovery.

    3. If you are not on the EBS Async Replication page, click Switch to EBS Async Replication.

    4. On the Site Pairs tab, click the target site pair, and then click the Protection Group tab.

    5. On the Protection Group tab, find the target protection group and click Enable Reverse Replication in the Actions column.

    6. In the Enable Reverse Replication panel, click Confirmation.

      Note

      If you enable reverse replication after the production site is recovered, you do not need to create instances or disks.

      The protection group status changes to Reverse Replicating Data.

    Reverse Protection - Failback

    After the production site recovers, you must perform a failback to restore data from the disaster recovery site to the production site. You can perform a failback when the protection group status is Reverse Replicating Data and the Actual RPO meets your requirements.

    Perform the following steps to perform a failback:

    1. Log on to the Cloud Backup console.

    2. In the navigation pane on the left, choose Disaster Recovery > ECS Disaster Recovery.

    3. If you are not on the EBS Async Replication page, click Switch to EBS Async Replication.

    4. On the Site Pairs tab, click the target site pair, and then click the Protection Group tab.

    5. On the Protection Group tab, find the target protection group. In the Actions column, click image..png and choose Reverse Protection > Failback.

    6. In the Start Failback dialog box, select Switch after data synchronization, configure policies for economical mode and for handling an insufficient instance specification, and then click OK.

      The protection group status changes to Failback in Progress.

      After the failback is complete, the protection group status changes to Failback Completed. At this point, the ECS instance at the production site is Running, and the ECS instance at the disaster recovery site is Stopped.

    7. After confirming the failback is complete, click image..png and choose Reverse Protection > Failback Completed.

      After confirmation, the protection group status changes to Dispatching.

    Switch Now

    Forward Protection - Failover

    1. Log on to the Cloud Backup console.

    2. In the navigation pane on the left, choose Disaster Recovery > ECS Disaster Recovery.

    3. If you are not on the EBS Async Replication page, click Switch to EBS Async Replication.

    4. On the Site Pairs tab, click the target site pair, and then click the Protection Group tab.

    5. On the Protection Group tab, find the target protection group. In the Actions column, click image..png and choose Forward Protection > Failover.

    6. In the Start Failover dialog box, select Switch now, configure the policy for handling an insufficient instance specification, and then click OK.

      Note

      • An instance in economical mode may fail to start due to insufficient instance specifications in the zone. In this case, select Upgrade within specification family. Cloud Backup then preferentially attempts to upgrade the instance within the specification family. The maximum CPU or memory size is three times that of the current instance specification.

      • If the automatic configuration upgrade fails or you select manual processing, modify the instance specifications in the ECS console based on the error message, and then retry the task in the task list.

      The protection group status changes to Failover in Progress.

      Important

      This operation may cause loss of some data. Proceed with caution.

      After the failover is complete, the protection group status changes to Failover Succeeded. Navigate to the Protected Instances page to verify the data and applications on the ECS instance.

    7. After verification, in the Actions column for the protection group, click image..png and choose Forward Protection > Failover Completed.

      The protection group status changes to Failover Confirmed. At this point, the ECS instance at the production site is Stopped, and the ECS instance at the disaster recovery site is Running.

    Enable Reverse Replication

    Reverse replication is the process of replicating data from the disaster recovery site to the production site for failback.

    1. Log on to the Cloud Backup console.

    2. In the navigation pane on the left, choose Disaster Recovery > ECS Disaster Recovery.

    3. If you are not on the EBS Async Replication page, click Switch to EBS Async Replication.

    4. On the Site Pairs tab, click the target site pair, and then click the Protection Group tab.

    5. On the Protection Group tab, find the target protection group and click Enable Reverse Replication in the Actions column.

    6. In the Enable Reverse Replication panel, click Confirmation.

      Note

      If you enable reverse replication after the production site is recovered, you do not need to create instances or disks.

      The protection group status changes to Reverse Replicating Data.

    Reverse Protection - Failback

    1. Log on to the Cloud Backup console.

    2. In the navigation pane on the left, choose Disaster Recovery > ECS Disaster Recovery.

    3. If you are not on the EBS Async Replication page, click Switch to EBS Async Replication.

    4. On the Site Pairs tab, click the target site pair, and then click the Protection Group tab.

    5. On the Protection Group tab, find the target protection group. In the Actions column, click image..png and choose Reverse Protection > Failback.

    6. In the Start Failback dialog box, select Switch now, configure policies for economical mode and for handling an insufficient instance specification, and then click OK.

      Important

      This operation may cause loss of some data. Proceed with caution.

      The protection group status changes to Failback in Progress.

      After the failback is complete, the protection group status changes to Failback Succeeded. At this point, the ECS instance at the production site is Running, and the ECS instance at the disaster recovery site is Stopped.

    7. After confirming the failback is complete, click image..png and choose Reverse Protection > Failback Completed.

      After confirmation, the protection group status changes to Dispatching.

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