When takeovers occur
Takeovers can be initiated manually or occur automatically when a failover event happens, depending on how you configure the HA pair. In some cases, takeovers occur automatically, regardless of configuration.
Takeovers can occur under the following conditions:
- A takeover is manually initiated.
- A node is in an HA pair with
the default configuration for immediate takeover on
panic, and that node undergoes a software or system failure that leads to a panic.
Note: The default setting for the cf.takeover.on_panic option is on. If the cf.takeover.on_panic option is set to on, a node panic will cause an automatic takeover. If the cf.takeover.on_panic option is set to off, a node panic will not cause an automatic takeover. You should not turn this option to off unless you are instructed by technical support to do so.
By default, after the partner has recovered from the panic and booted up, the node automatically performs a giveback, returning the partner to normal operation.
- A node that is in an HA pair undergoes a system failure (for example, a loss of power) and cannot reboot. Note: If the storage for a node also loses power at the same time, a standard takeover is not possible. For MetroCluster configurations, you can initiate a forced takeover in this situation.
- One or more network interfaces that are configured to support failover become unavailable.
- A node does not receive heartbeat messages from its partner.
This could happen if the partner experienced a hardware or software failure that did not result in a panic but still prevented it from functioning correctly.
- You halt one of the nodes without using the -f parameter.
- You reboot one of the nodes without using the -f parameter.
- Hardware-assisted takeover is enabled and triggers a takeover when the remote management device (RLM or Service Processor) detects failure of the partner node.