If the protected site is offline and Site Recovery Manager cannot perform its tasks in a timely manner, this increases the RTO to an unacceptable level. In such a case, you can run a recovery plan with the forced recovery option. Forced recovery starts the virtual machines on the recovery site without performing any operations on the protected site.
When to Use Forced Recovery
You can use forced recovery in cases where infrastructure fails at the protected site and, as a result, protected virtual machines are unmanageable and cannot be shut down, powered off, or unregistered. In such a case, the system state cannot be changed for extended periods.
Forcing recovery does not complete the process of shutting down the virtual machines at the protected site. As a result, a split-brain scenario occurs, but the recovery can finish more quickly.
Forced Recovery with vSphere Replication
When running disaster recovery using vSphere Replication, Site Recovery Manager prepares vSphere Replication storage for reprotect and you do not have to verify mirroring as you do with array-based replication.
Forced Recovery with Array-Based Replication
Running disaster recovery with array-based replication when the storage array of the protected site is offline or unavailable can affect the mirroring between the protected and the recovery storage arrays.
After you run forced recovery, you must check whether mirroring is set up correctly between the protected array and the recovery array before you can perform further replication operations. If mirroring is not set up correctly, you must repair the mirroring by using the storage array software.
When you enable forced recovery while the protected site storage is still available, any outstanding changes on the protection site are not replicated to the recovery site before the sequence begins. Replication of the changes occurs according to the recovery point objective (RPO) period of the storage array.
If a new virtual machine or template is added on the protection site and recovery is initiated before the storage RPO period has elapsed, the new virtual machine or template does not appear on the replicated datastore and is lost. To avoid losing the new virtual machine or template, wait until the end of the RPO period before running the recovery plan with forced recovery.
After the forced recovery finishes and you have verified the mirroring of the storage arrays, you can resolve the issue that necessitated the forced recovery.
After you resolve the underlying issue, run planned migration on the recovery plan again, resolve any problems that occur, and rerun the plan until it finishes successfully. Running the recovery plan again does not affect the recovered virtual machines at the recovery site.
Enabling Forced Recovery
To select forced recovery when running disaster recovery, you must enable the option recovery.forceRecovery in Advanced Settings on the Site Recovery Manager Server on the recovery site. For more information, see Change Recovery Settings.
In the Run Recovery Plan wizard, you can only select the forced recovery option in disaster recovery mode. This option is not available for planned migration.
Planned Migration after Forced Recovery
When you run planned migration after running a forced recovery, virtual machines on the protected site might fail to shut down if the underlying datastores are read only or unavailable. In this case, log into vCenter Server on the protected site and power off the virtual machines manually. After you have powered off the virtual machines, run planned migration again.