Two system cluster where one system fails
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Two system cluster where one system fails

In this example, System1 fails, and System0 carries out the I/O fencing operation as follows:

• The GAB module on System0 determines System1 has failed due to loss of heartbeat signal reported from LLT.
• GAB passes the membership change to the fencing module on each system in the cluster.

  The only system that is still running is System0

• System0 gains control of the coordinator disks by ejecting the key registered by System1 from each coordinator disk.

  The ejection takes place one by one, in the order of the coordinator disk's serial number.

• When the fencing module on System0 successfully controls the coordinator disks, HAD carries out any associated policy connected with the membership change.
• System1 is blocked access to the shared storage, if this shared storage was configured in a service group that was now taken over by System0 and imported.

  I/O Fencing example with system failure

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