Configuring failover peers
You configure Core high availability by choosing Configure > Failover: Failover Configuration. To configure failover peers for Core, you need to provide the following information for each of the Core peers:
• The IP address of the peer appliance
• The local failover interface through which the peers exchange and monitor heartbeat messages
• An additional IP address of the peer appliance
• An additional local failover interface through which the peers exchange and monitor heartbeat messages
You can configure any interface as a failover interface, but to maintain some consistency we recommend that you configure and use eth1_2 and eth1_3 as dedicated failover interfaces selected from the Local Interface drop-down list. Also in the Configuration page you can select the interface you want to use for connections from the failover peer Edge appliances.
After you click Enable Failover, the Core attempts to connect through the failover interfaces sending the storage configuration to the peer. If successful, you see the Device Failover Settings.
After the Core failover has been successfully configured, you can log in to the Management Console of the peer Core and view its Failover Configuration page.
Even though the relevant failover interfaces are automatically configured on the peer, you must configure the peer Preferred Interfaces for Edge Connections. By default, the primary interface is selected.
In the Core CLI, you can configure failover using the device-failover peer and device-failover peerip commands. To display the failover settings use the show device-failover command.
If the failover configuration is not successful, then details are available in the Core log files and a message is displayed in the user interface. The failure can be for any number of different reasons. Some examples, along with items to check, are as follows:
• Unable to contact peer—Check the failover interface configurations (IP addresses, interface states and cables).
• Peer is already configured as part of a failover pair—Check that you have selected the correct Core.
• The peer configuration includes one or more exports that are already assigned to the other Core in the failover pair—Check the export assignments and correct the configuration.
• The peer configuration includes one or more Edge appliances that are already assigned to the other Core in the failover pair—Check the Edge assignments and correct the configuration.
After the failover configuration is complete and active, the configurations of the two peers in the cluster are periodically exchanged through a TCP connection using port 7971 on the failover interfaces. If you change or save either Core configuration, the modified configuration is sent to the failover peer. In this way, each peer always has the latest configuration details of the other.
You configure any Edge that is connecting to a Core HA configuration with the primary Core details (hostname or IP). After connected to the primary Core, the Edge is automatically updated with the peer Core information. This information ensures that during a Core failover situation in which an Edge loses its primary Core, the secondary Core can signal the Edge that it is taking over. The automatic update also minimizes the configuration activities required at the Edge regardless of whether you configure Core HA or not.