Unplanned failover of applications

When the primary site of the given application is unreachable, you can run unplanned failover of applications to your local cluster.

About this task

Go through the following points before you start the unplanned failover of an application:
  • Important: In this document, the site where the application is running is the primary site and peer site is the secondary site of an application.
  • Run the unplanned failover from any of the following racks:
    • In case of rack shutdown, from the surviving rack.
    • In case of network disconnection, from the rack where the applications must be redeployed.
    • In case of AFM shutdown, from the rack AFM that is in good state.
  • To prepare the cluster to host the selected applications, the failover procedure creates the PVs, which are needed for the application to access data.
  • When you create applications and PVCs on a primary site, its associated PVs or filesets have a quota limit. You can replicate the entire data on the primary to the secondary as no quota limit exists in the secondary. The following issues can occur because of quota limit:
    • Some data may not get replicated when you do a failover from the new primary without quota limits to the new secondary with quota limits.
    • In the new secondary site, the Regional status of some of these failover applications may show as RPO missed
    • The Snapshot may go missing for few applications post restart replication
    In such situations, increase the quota on the new secondary before you do a failover. For the procedure to increase the quota, see Volume expansion.

Procedure

  1. Go to Disaster Recovery > Replicated applications.
  2. Click Actions > Force failover.
    The Force failover page is displayed. The table lists applications that run on the secondary site.
  3. Select the applications you wish to failover or relocate to the secondary site.
  4. Click Failover.
  5. In the Replicated applications page, check the status of the Primary site.
    Initially, the status of the Primary site for the application is Failing over. After completion, it displays
    Relocate icon
    icon next to the name of the Primary site. A failover initiated notification is displayed. IBM Storage Fusion HCI System prepares the site or cluster for deployment of the relocated applications. A Failover complete notification is displayed to confirm that the cluster is prepared for the deployment of the applications.

What to do next

After the failover is complete, deploy the applications on your local cluster.

After forced failover, restart replication option is provided on the old primary, that is, for applications that were forced failed over to the peer cluster. For the procedure to restart, Restarting replication.