You can initiate takeovers manually or they can 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:
- When you manually initiate takeover
- When a node in an HA pair with the default configuration for immediate takeover on panic undergoes a software or system failure that leads to a panic
By default, the node automatically performs a giveback, returning the partner to normal operation after the partner has recovered from the panic and booted up.
- When a node 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.
- When 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.
- When hardware-assisted takeover is enabled and it triggers a takeover when the remote management device (Service Processor) detects failure of the partner node