This section explains the failback operation from the backup site to the primary site after the hardware environment on primary site is recovered.
Failback can be performed with the same procedure as switchover, however, the following operations must be performed in advance.
Clear Management Software Information
When a disaster does not damage the entire primary site, it is possible that some management software information remains in hardware that has not been damaged in the disaster. Examples of such management software information are host affinity on ETERNUS and reserved DHCP addresses. In that case, clear any remaining management software information on the recovered primary site.
Also, if an unplanned switchover (one that switches to the backup site without being able to access the primary site) is performed on an environment for physical L-Server switchover (physical OS) or physical/virtual L-Server switchover (VM host/VM guest), the VIOM information on the previous primary site may not match the actual physical server status.
To correct the status after an unplanned switchover, perform inventory boot on all physical servers managed by VIOM of the previous primary site before performing failback.
Install the Primary Site
Configure the environment on the primary site for failback. This environment needs to be prepared in the same way as the backup site was. For details on the installation procedure, refer to "Chapter 3 Installation".
Create Files Used for Switchover
Edit the files created in "3.6 Creating Files Used for Switchover".
Replace the contents of resources on the switchover source site with that of resources on the switchover destination site.
Collect Failback Information
Collect failback information from the backup site. For details on how to collect the failback information, refer to "4.1 Normal Operation".
Start Replication from the Backup Site
Start storage unit replication from the backup site to the primary site.
For the Active-Active operation, the following operations must be performed after failback.
Recovery of Definition Files
When definition files are merged in "4.2.8 Restoring the Configuration Files of the Switchover Source Site [Switchover Destination Site]", delete unnecessary configurations from definition files on the backup site (failback source site).
Deletion of Unnecessary Resources
Even when performing failback by tenant, users, user groups, and L-Server templates are imported with the resources on the backup site. Delete any unnecessary resources manually.
Note
In the following cases, ensure storage unit LUN replication from the switchover destination site to the switchover source site is performed.
There are physical L-Server disks created using dynamic LUN mirroring. and,
When replication has been performed using a copy pair automatically defined when creating an L-Server during failback.
In this condition, the disk after failback is handled in the same way as a disk allocated during dynamic LUN mirroring in normal operation.
When deleting a disk allocated in the dynamic LUN mirroring, LUN replication stops and the replication destination disk is also deleted.
When storage unit LUN replication from the switchover source site to the switchover destination site is not performed, an error will occur when deleting an L-Server or a disk.
