Reconfiguring a Cluster

Select the cluster on the map or tree. From the Actions menu, select Configuration. MAX_CONFIGURED _PACKAGES is in the Parameters tab.

In Serviceguard A.11.17, you can change MAX_CONFIGURED_PACKAGES while the cluster is running. The default in A.11.17 is that MAX_CONFIGURED_PACKAGES is the maximum number allowed in the cluster.

In Serviceguard A.11.17, you can change MAX_CONFIGURED_PACKAGES while the cluster is running. The default in A.11.17 is that MAX_CONFIGURED_PACKAGES is the maximum number allowed in the cluster.

Use the cmgetconf command to obtain a current copy of the cluster's existing configuration. Example:

# cmgetconf -c cluster_name clconfig.ascii 

Edit the clconfig.ascii file to include the desired value for MAX_CONFIGURED_PACKAGES. Then use the cmcheckconf command to verify the new configuration. Using -k or -K option with the cmcheckconf command, can significantly reduce the response time.

Use the cmapplyconf command to apply the changes to the configuration and send the new configuration file to all cluster nodes. Using -k or -K option with the cmcheckconf command, can significantly reduce the response time.

Select the cluster on the tree or map. Choose Configuring from the Actions menu. You need root permission on the cluster. On the Nodes tab, under Available nodes, highlight the node you want to add, and click Add. Then click Apply. After Refresh, check the cluster’s Properties to confirm the change.

Use the following procedure to add a node with HP-UX commands. For this example, nodes ftsys8 and ftsys9 are already configured in a running cluster named cluster1, and you are adding node ftsys10.

Use cmrunnode to start the new node, and, if desired, set the AUTOSTART_CMCLD parameter to 1 in the /etc/rc.config.d/cmcluster file to enable the new node to join the cluster automatically each time it reboots.

	NOTE: If you add a node to a running cluster that uses CVM disk groups, the disk groups will be available for import when the node joins the cluster. To add a node to the cluster, it must already have connectivity to the disk devices for all CVM disk groups

The node must be halted. If it is not, select it and choose Administering Serviceguard from the Actions menu. Choose Halt Node.

Select the cluster on the tree or map. Choose Configuring Serviceguard from the Actions menu. (You need root permission on the cluster.) On the Nodes tab, under Available nodes, highlight the node to remove, and click Delete. Then click Apply. After Refresh, check the cluster’s Properties to confirm the change.

You cannot delete the session server node.

If the node you wish to delete is unreachable (disconnected from the LAN, for example), you can delete the node only if there are no packages which specify the unreachable node. If there are packages that depend on the unreachable node, halt the cluster or use Serviceguard commands as described in the next section.

Use the following procedure to delete a node with HP-UX commands. For this example, nodes ftsys8, ftsys9 and ftsys10 are already configured in a running cluster named cluster1, and you are deleting node ftsys10.

	NOTE: If you want to remove a node from the cluster, issue the cmapplyconf command from another node in the same cluster. If you try to issue the command on the node you want removed, you will get an error message.

	NOTE: If you are attempting to remove an unreachable node that has many packages dependent on it, especially if the dependent packages use a large number of EMS resources, you may see the following message: The configuration change is too large to process while the cluster is running. Split the configuration change into multiple requests or halt the cluster. In this situation, you must halt the cluster to remove the node.

Select the cluster on the tree or map. Choose Configuring Serviceguard from the Actions menu. (You need root permission on the cluster.) On the Logical Volumes tab highlight the node to add or remove, and click Add or Delete. Then click Apply. After Refresh, check the cluster’s Properties to confirm the change.

You cannot change the cluster lock volume group or physical volume configuration while the cluster is running.

	NOTE: If you are removing a volume group from the cluster configuration, make sure that you also modify or delete any package control script that activates and deactivates this volume group. In addition, you should use the LVM vgexport command on the removed volume group from each node that will no longer be using the volume group.

From the LVM’s cluster, follow these steps:

	NOTE: If the volume group that you are deleting from the cluster is currently activated by a package, the configuration will be changed but the deletion will not take effect until the package is halted; thereafter, the package will no longer be able to run without further modification, such as removing the volume group from the package control script.

You can add VxVM disk groups to the cluster configuration while the cluster is running. To add new CVM disk groups, the cluster must be running.

Create CVM disk groups from the CVM Master Node:

Similarly, you can delete VxVM or CVM disk groups provided they are not being used by a cluster node at the time.

	NOTE: If you are removing a disk group from the cluster configuration, make sure that you also modify or delete any package control script that imports and deports this disk group. If you are removing a disk group managed by CVM without CFS, be sure to remove the STORAGE_GROUP entries for the disk group from the package ASCII file. If you are removing a disk group managed by CVM with CFS, be sure to remove the DEPENDENCY parameter.

Serviceguard manages the VERITAS processes, specifically gab and LLT. As a result, the administration commands such as gabconfig, llthosts, and lltconfig should never be used for administering a cluster. It is safe to use the read-only uses of these commands, such as gabconfig -a. But an administrative command could potentially crash nodes or an entire cluster.