A failover is the process of switching from the original VM on the source host/cluster to a replica VM on a target host/cluster. Since the replica VM is stored in a ready-to-run state, this can be done in a matter of minutes, ensuring quick access and minimal downtime, in turn ensuring a low RTO.
A failover can be either permanent or temporary until the main site is available again and a failback can be performed. A permanent failover is often used if the target site is designed to run production workloads, and subsequently a failback is used when it is desirable to move the workload back to the original site once any availability issues have been resolved.
When a failover is performed, the following happens to the replica VM:
The replicated VM rolls back to the selected restore point.
The replicated VM is powered on in the target host/cluster.
All changes made to the replicated VM while it runs in the failover state are written to the delta file of the snapshot...