System information

Site Recovery Manager uses VMware Tools heartbeat to discover when a virtual machine is running on the
recovery site. In this way, Site Recovery Manager can ensure that all virtual machines are running on the
recovery site. For this reason, VMware recommends that you install VMware Tools on protected virtual
machines. If you do not or cannot install VMware Tools on the protected virtual machines, you must
configure Site Recovery Manager not to wait for VMware Tools to start in the recovered virtual machines
and to skip the guest operating system shutdown step. See “Change Recovery Settings,” on page 105.
After Site Recovery Manager completes the final replication, Site Recovery Manager makes changes at both
sites that require significant time and effort to reverse. Because of this time and effort, you must assign the
privilege to test a recovery plan and the privilege to run a recovery plan separately.
Running a Recovery with Forced Recovery
If the protected site is offline and Site Recovery Manager cannot perform its usual tasks in a timely manner
which increases the RTO to unacceptable level, you can run the recovery with the forced recovery option.
Forced recovery starts the virtual machines on the recovery site without performing any operations on the
protected site.
CAUTION Only use forced recovery in cases where the recovery time objective (RTO) is severely affected by
a lack of connectivity to the protection site.
Forced recovery is for use 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. To resolve this situation, you can force recovery.
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 might complete more quickly.
Running disaster recovery with array-based replication when the protected site storage array is offline or
unavailable can affect the mirroring between the protected and the recovery storage arrays. After you run
forced recovery, you must check that 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 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.
When you enable forced recovery when 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.
To select forced recovery when running disaster recovery, you must enable the option
recovery.forceRecovery in Advanced Settings on the recovery Site Recovery Manager server. In the Run
Recovery Plan wizard, select the forced recovery option only in disaster recovery mode. It is not available
for planned migration.
After the forced recovery completes 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.
Site Recovery Manager Administration
44 VMware, Inc.