Automatic Failover; Reprotection; Automated Failback - Dell EMC ME4 Series User Manual

Automatic failover

SRM automates the execution of recovery plans to ensure accurate and consistent execution. Through the vCenter Server you can gain
full visibility and control of the process, including the status of each step, progress indicators, and detailed descriptions of any error that
occurs.
In the event of a disaster when an SRM actual failover is requested, the SRA will perform the following steps:
1 Select the replicated volumes.
2 Identify and remove any incomplete remote copies that are in progress and present the most recently completed Remote Copy as a
primary volume.
3 Convert remote volumes into primary volumes and configure authentication for ESXi hosts to mount them.
If an actual failover does not run completely for any reason, the failover can be called many times to try to complete the run. If, for example,
only one volume failed to restore and that was due to a normal snapshot being present, the snapshot could be manually deleted and the
failover be requested again.

Reprotection

After a recovery plan or planned migration is executed, there are often cases where the environment must continue to be protected against
failure in order to ensure its resilience or to meet all disaster recovery objectives.
Reprotection is an SRM extension to recovery plans for use only with storage system replication. It enables the environment at the
recovery site to establish synchronized replication and protection of the original environment.
After failover of the recovery site, choosing to reprotect the environment will establish synchronization and attempt to replicate the data
between the protection groups running at the recovery site and at the previously protected primary site.
This capability to reprotect an environment ensures that environments are protected against failure even after a site recovery scenario. It
also enables automated failback to a primary site following a migration or failover.

Automated failback

You can set up an automated failback workflow to return the entire environment to the primary site from the recovery site.
The failback happens after the reprotection has ensured that data replication and synchronization are established to the original primary
site.
Automated failback runs the same workflow that was used to migrate the environment to the protected site. It ensures that the critical
systems encapsulated by the recovery plan are returned to their original environment. The workflow executes only if reprotection is
successfully completed. Failback is only available with storage system replication.
Failback ensures the following:
• All virtual machines that were initially migrated to the recovery site are moved back to the primary site.
• Environments that require that disaster recovery testing be done with live environments with genuine migrations can be returned to
their initial site.
• Simplified recovery processes enable a return to standard operations after a failure.
• Failover can be done in case of disaster or in case of planned migration.
10 Using SRM for disaster recovery