Avaya Aura System Platform Installing And Configuring page 96

How System Platform High Availability Failover works
1. If the crossover link is interrupted on any node, no action will result because both machines
have the same score.
2. If the public link is interrupted on the standby node, no action will result because the active
node still has the full score while the standby node has lost 2 ping sources.
3. If the public link is interrupted on the active node, heartbeat will initiate failover because active
node has lost 2 ping sources while the standby has the full score.
Note:
The default gateway is the ping target and it is not a configurable parameter. Ensure that your gateway
replies to ICMP pings which have payloads larger that the defaults and come from the System Platform
nodes.
DRBD initial data synchronization
System Platform High Availability Failover uses the Distributed Replicated Block Device (DRBD)
component to propagate online changes that are made on the active node. Each Logical Volume that is
propagated by DRBD uses separate DRBD resource. List of these DRBD resources and their states can
be checked on the System Platform Failover page. However, before the initial synchronization of the DRBD
resources is completed, the standby node does not have the reliable data that could be used to start the
virtual machines. The time interval during initial data block synchronization is called initial data
synchronization. The following image depicts the initial data synchronization from the active node to the
standby node:
96 Installing and Configuring Avaya Aura
™
System Platform April 2010