Appendix D.1 Example of hardware configuration and overview of MC/ServiceGuard behavior

When MC/ServiceGuard detects a failure in a monitored system (hereafter called the primary system), it switches processes to the secondary system (hereafter called the standby system) to continue services. This function is called failover. Behavior of a failover differs depending on whether the mode is in local node operation or multiple node operation. Examples of hardware configuration and an overview of failover for the respective operations are as follows.

Organization of this subsection
(1) Example of local node operation
(2) Example of multiple node operation

(1) Example of local node operation

The following example shows a double LAN configuration, one LAN is the primary LAN and the other is the standby LAN. Supported LAN cards are connected to each LAN.

In this configuration, when a failure occurs in the primary LAN card, the connection will be switched to the standby LAN card that resides on the same node. The following figure shows an example of local node operation.

Figure D-1 Example of local node operation

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(2) Example of multiple node operation

The example below shows a double LAN configuration.

One LAN is the primary LAN and the other is the standby LAN, and supported LAN cards are connected to each node. This is a double LAN communication line configuration consisting of either a heartbeat-dedicated LAN or a heartbeat line using RS232 signals, in addition to the primary LAN. The disk storage device is shared between nodes.

If a failure occurs in the primary node and MC/ServiceGuard determines that a failover to another node is needed, MC/ServiceGuard stops the primary system and starts the package on the standby system to continue services. The shared disk is mounted on the standby system. The following figure shows an example of multiple node operation.

Figure D-2 Example of multiple node operation (MC/ServiceGuard)

[Figure]