How automatic takeover and giveback work

The automatic takeover and giveback operations can work together to reduce and avoid client outages.

With the default settings, if one node in the HA pair panics or reboots, the partner node automatically takes over and then automatically gives back storage when the affected node reboots. This returns the HA pair to a normal operating state.

The automatic giveback occurs by default. You can also configure the system to not perform automatic giveback if you want to control giveback impact on clients using the storage failover modify-auto-giveback false-node < node command. Before performing the automatic giveback (regardless of what triggered it), the partner node waits for a fixed amount of time as controlled by the -delay-seconds parameter of the storage failover modify command. The default delay is 600 seconds. By delaying the giveback, the process results in two brief outages:

  1. One outage during the takeover operation
  2. One outage during the giveback operation
This process avoids a single, prolonged outage that includes:
  1. The time for the takeover operation
  2. The time it takes for the taken-over node to boot up to the point at which it is ready for the giveback
  3. The time for the giveback operation

If the automatic giveback fails for any of the non-root aggregates, the system automatically makes two additional attempts to complete the giveback.

Note: During the takeover process, the auto giveback process starts before the partner node is ready for the giveback. When the time limit of the auto giveback process expires and the partner node is still not ready, the timer restarts. As a result, the time between the partner node being ready and the actual giveback being performed might be shorter than the auto giveback time.