HP Serviceguard manual Reconfiguring a Running Cluster, Cmgetconf -c cluster1 temp.ascii

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.

1.Use the following command to store a current copy of the existing cluster configuration in a temporary file:

cmgetconf -c cluster1 temp.ascii

2.Specify a new set of nodes to be configured and generate a template of the new configuration. Specify the node name (39 bytes or less) without its full domain name; for example, ftsys8 rather than ftsys8.cup.hp.com. Enter a command such as the following (all on one line):

cmquerycl -C clconfig.ascii -c cluster1 -n ftsys8 -n ftsys9 -n ftsys10

3.Open clconfig.ascii in an editor and check that the information about the new node is what you want.

4.Verify the new configuration: cmcheckconf -C clconfig.ascii

5.Apply the changes to the configuration and distribute the new binary configuration file to all cluster nodes:

cmapplyconf -C clconfig.ascii

Use cmrunnode to start the new node, and, if you so decide, 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: Before you can add a node to a running cluster that uses Veritas CVM, the node must already be connected to the disk devices for all CVM disk groups. The disk groups will be available for import when the node joins the cluster.

Removing Nodes from the Cluster while the Cluster Is Running

You can use Serviceguard Manager to delete nodes, or Serviceguard commands as shown below. The following restrictions apply:

•The node must be halted. See “Removing Nodes from Participation in a Running Cluster” (page 279).

•If the node you want 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

296 Cluster and Package Maintenance