HA override

The HA override CLI keyword is disabled by default. When override is disabled a cluster may not always renegotiate when an event occurs that affects primary unit selection. For example, when override is disabled a cluster will not renegotiate when you change a cluster unit device priority or when you add a new cluster unit to a cluster. This is true even if the unit added to the cluster has a higher device priority than any other unit in the cluster. Also, when override is disabled a cluster does not negotiate if the new unit added to the cluster has a failed or disconnected monitored interface.


	For a virtual cluster configuration, override is enabled by default for both virtual clusters when you enable virtual cluster 2. For more information, see “Virtual clustering and HA override”.

In most cases you should keep override disabled to reduce how often the cluster negotiates. Frequent negotiations may cause frequent traffic interruptions.

However, if you want to make sure that the same cluster unit always operates as the primary unit and if you are less concerned about frequent cluster negotiation you can set its device priority higher than other cluster units and enable override.

To enable override, connect to each cluster unit CLI (using the execute ha manage command) and use the config system ha CLI command to enable override.

For override to be effective, you must also set the device priority highest on the cluster unit that you want to always be the primary unit. To increase the device priority, from the CLI use the config system ha command and increase the value of the priority keyword to a number higher than the default priority of 128.

You can also increase the device priority from the web‑based manager by going to System > Config > HA. To increase the device priority of the primary unit select edit for the primary or subordinate unit and set the Device Priority to a number higher than 128.


	The override setting and device priority value are not synchronized to all cluster units. You must enable override and adjust device priority manually and separately for each cluster unit.

With override enabled, the primary unit with the highest device priority will always become the primary unit. Whenever an event occurs that may affect primary unit selection, the cluster negotiates. For example, when override is enabled a cluster renegotiates when you change the device priority of any cluster unit or when you add a new unit to a cluster.