In order to configure an SMA appliance as a standby appliance, there must be more than one SMA appliance in the CMS cluster.
An active appliance with ongoing user sessions can be configured to become a standby appliance. Once the appliance becomes a standby appliance, new user connections to the GTO service name are no longer directed to that appliance.
A standby appliance can be configured to become an active appliance by an administrator only from the Central Management Console.
To add a standby appliance to the CMS
Navigate to Managed Appliances > Add/Remove.
Click on the name of the appliance that you want to configure as a standby appliance.
The Edit Appliance Settings dialog displays.
Select Standby appliance.
When you select Standby appliance, DNS authoritative server is automatically selected. Leave this option selected.
This appliance will now start operating as a standby appliance and stop processing user connections until activated.