You might want to force a failover if, for example, you need to replace or upgrade the primary NetScaler instance. You can force failover from either the primary instance or the secondary instance. When you force a failover on the primary instance, the primary becomes the secondary and the secondary becomes the primary. Forced failover is only possible when the primary instance can determine that the secondary instance is UP.
A forced failover is not propagated or synchronized. To view the synchronization status after a forced failover, you can view the status of the instance.
A forced failover fails in any of the following circumstances:
- You force failover on a standalone system.
- The secondary instance is disabled or inactive. If the secondary instance is in an inactive state, you must wait for its state to be UP to force a failover.
- The secondary instance is configured to remain secondary.
The NetScaler instance displays a warning message if it detects a potential issue when you run the force failover command. The message includes the information that triggered the warning, and requests confirmation before proceeding.
You can force a failover on a primary instance or on a secondary instance.