Managing Serviceguard Nineteenth Edition, Reprinted June 2011

IMPORTANT: See “What Happens when You Change the Quorum Configuration Online”
(page 47) for important information.
1. In the cluster configuration file, modify the values of FIRST_CLUSTER_LOCK_PV and
SECOND_CLUSTER_LOCK_PV for each node.
2. Run cmcheckconf to check the configuration.
3. Run cmapplyconf to apply the configuration.
For information about replacing the physical disk, see “Replacing a Lock Disk” (page 311).
Updating the Cluster Lock LUN Configuration Online
You can change the lock LUN configuration while the cluster is running. Proceed as follows.
IMPORTANT: See “What Happens when You Change the Quorum Configuration Online”
(page 47) for important information.
1. In the cluster configuration file, modify the value of CLUSTER_LOCK_LUN for each node.
2. Run cmcheckconf to check the configuration.
3. Run cmapplyconf to apply the configuration.
For information about replacing the physical device, see “Replacing a Lock LUN” (page 312).
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 13 (page 278),
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.
282 Cluster and Package Maintenance