Saturday, April 28, 2007

Step by step: How to install exchange 2003 cluster part XII

Simulate a network failure and recovery.
1. On the passive node, go to the "Edit configuration"
2. Change "Local Network" virtual network to "Not connected"
3. The passive node will reports that the nework lost connection.
4. Try to fail over, it should fail, but the active node knows that the passive server is alive.
5. Change "Not connected" to "Local Network" virtual network
6. Change the "HeartBeat" virtual network to "Not connected"
7. Try to fail over, it should work this time.
8. Enable the "HeartBeat" virtual network.

What happened?
Local network is mixed mode, and HeartBeat is dedicated heartbeat network.
The whole purpose of the heartBeat network is to make sure each node knows about others and prevent them from become active when "Local Network" fails.
As you can see, in this lab if both nodes try to be active, that would be a real disaster! and we prevented it.
There is a case you might need only "Local Network" which uses mixed mode. You might need it when you create a campus cluster or geo cluster. Hopefully you have at least 2 ISP and they can back up each other.

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