Managing Serviceguard Eighteenth Edition, September 2010

Reconfiguring a Halted Cluster
You can make a permanent change in the cluster configuration when the cluster is
halted. This procedure must be used for changes marked “Cluster must not be running”
in Table 7-2 (page 359), but it can be used for any other cluster configuration changes
as well.
Use the following steps:
1. Halt the cluster on all nodes, using Serviceguard Manager’s Halt Cluster
command, or cmhaltcl on the command line.
2. On one node, reconfigure the cluster as described in the chapter “Building an HA
Cluster Configuration.” You can do this by using Serviceguard Manager, or by
entering cmquerycl on the command line to generate an ASCII file, which you
then edit.
3. Make sure that all nodes listed in the cluster configuration file are powered up
and accessible. To copy the binary cluster configuration file to all nodes, use
Serviceguard Manager’s Apply button, or enter cmapplyconf on the command
line. This file overwrites any previous version of the binary cluster configuration
file.
4. Start the cluster on all nodes or on a subset of nodes. Use Serviceguard Manager’s
Run Cluster command, or cmruncl on the command line.
Reconfiguring a Running Cluster
This section provides instructions for changing the cluster configuration while the
cluster is up and running. Note the following restrictions:
• You cannot remove an active node from the cluster. You must halt the node first.
• You cannot delete an active volume group from the cluster configuration. You
must halt any package that uses the volume group and ensure that the volume is
inactive before deleting it.
• 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).
Changes to the package configuration are described in a later section.
Adding Nodes to the Cluster While the Cluster is Running
You can use Serviceguard Manager to add nodes to a running cluster, or use
Serviceguard commands as in the example below.
In this example, nodes ftsys8 and ftsys9 are already configured in a running cluster
named cluster1, and you are adding node ftsys10.
Reconfiguring a Cluster 365