Managing HP Serviceguard for Linux, Tenth Edition, September 2012

Changes that Will Trigger Warnings
Changes to the following will trigger warnings, giving you a chance to cancel, if the
change would cause the package to fail.
NOTE: You will not be able to cancel if you use cmapplyconf -f.
• Package nodes
• Package dependencies
• Package weights (and also node capacity, defined in the cluster configuration file)
• Package priority
• auto_run
• failback_policy
Responding to Cluster Events
Serviceguard does not require much ongoing system administration intervention. As long
as there are no failures, your cluster will be monitored and protected. In the event of a
failure, those packages that you have designated to be transferred to another node will
be transferred automatically. Your ongoing responsibility as the system administrator will
be to monitor the cluster and determine if a transfer of package has occurred. If a transfer
has occurred, you have to determine the cause and take corrective actions.
The typical corrective actions to take in the event of a transfer of package include:
• Determining when a transfer has occurred.
• Determining the cause of a transfer.
• Repairing any hardware failures.
• Correcting any software problems.
• Restarting nodes.
• Transferring packages back to their original nodes.
• Enabling package switching.
Single-Node Operation
In a multi-node cluster, you could have a situation in which all but one node has failed,
or you have shut down all but one node, leaving your cluster in single-node operation.
This remaining node will probably have applications running on it. As long as the
Serviceguard daemon cmcld is active, other nodes can rejoin the cluster.
If the Serviceguard daemon fails when the cluster is in single-node operation, it will leave
the single node up and your applications running
NOTE: This means that Serviceguard itself is no longer running.
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