Managing HP Serviceguard for Linux, Seventh Edition, July 2007

Cluster and Package Maintenance
Reconfiguring a Cluster
Chapter 7 253
Updating the Cluster Lock LUN Configuration Offline
The cluster must be halted before you change the lock LUN
configuration. Proceed as follows:
Step 1. Halt the cluster.
Step 2. In the cluster configuration file, modify the values of CLUSTER_LOCK_LUN
for each node.
Step 3. Run cmcheckconf to check the configuration.
Step 4. Run cmapplyconf to apply the configuration.
If you need to replace the physical device, see “Replacing a Lock LUN” on
page 288.
Reconfiguring a Running Cluster
You can add new nodes to the cluster configuration or delete nodes from
the cluster configuration while the cluster is up and running. Note the
following, however:
• You cannot remove an active node from the cluster. You must halt the
node first.
• The only configuration change allowed while a node is unreachable
(for example, completely disconnected from the network) is to delete
the unreachable node from the cluster configuration. If there are also
packages that depend upon that node, the package configuration
must also be modified to delete the node. This all must be done in one
configuration request (cmapplyconf command).
• The access control list for the cluster can be changed while the
cluster is running.
Changes to the package configuration are described in a later section.
The following sections describe how to perform dynamic reconfiguration
tasks.
Adding Nodes to the Configuration While the Cluster is Running
Use the following procedure to add a node. For this example, nodes
ftsys8 and ftsys9 are already configured in a running cluster named
cluster1, and you are adding node ftsys10.