HP Serviceguard manual Preventing Automatic Activation of LVM Volume Groups

You can use these commands to test cluster operation, as in the following:

1.If the cluster is not already running, start it. From the Serviceguard Manager menu, choose Run Cluster. From the command line, use cmruncl -v.

By default, cmruncl will check the networks. Serviceguard will probe the actual network configuration with the network information in the cluster configuration. If you do not need this validation, use cmruncl -v-wnone instead, to turn off validation and save time

2.When the cluster has started, make sure that cluster components are operating correctly. you can use Serviceguard Manager to do this, or use the command cmviewcl -v.

Make sure that all nodes and networks are functioning as expected. For more information, see Chapter 7: “Cluster and Package Maintenance” (page 261).

3.Verify that nodes leave and enter the cluster as expected using the following steps:

•Halt the node. You can use Serviceguard Manager or use the cmhaltnode command.

•Check the cluster membership to verify that the node has left the cluster. You can do this in Serviceguard Manager, or use the cmviewcl command.

•Start the node. You can use Serviceguard Manager or use the cmrunnode command.

•To verify that the node has returned to operation, check in Serviceguard Manager, or use the cmviewcl command again.

4.Bring down the cluster. You can do this in Serviceguard Manager, or use the cmhaltcl -v-fcommand.

Additional cluster testing is described in See “Troubleshooting Your Cluster” (page 321). Refer to Appendix A for a complete list of Serviceguard commands. Refer to the Serviceguard Manager Help for a list of Serviceguard Administrative commands.

Preventing Automatic Activation of LVM Volume Groups

It is important to prevent LVM volume groups that are to be used in packages from being activated at system boot time by the/etc/lvmrc file. One way to ensure that this does not happen is to edit the /etc/lvmrc file on all nodes, setting AUTO_VG_ACTIVATE to 0, then including all the volume groups that are not cluster-bound in the custom_vg_activation function. Volume groups that will be used by packages should not be included anywhere in the file, since they will be activated and deactivated by control scripts.

NOTE: Special considerations apply in the case of the root volume group:

•If the root volume group is mirrored using MirrorDisk/UX, include it in the custom_vg_activation function so that any stale extents in the mirror will be re-synchronized.

•Otherwise, the root volume group does not need to be included in the

custom_vg_activation function, because it is automatically activated before the/etc/ lvmrc file is used at boot time.

Setting up Autostart Features

Automatic startup is the process in which each node individually joins a cluster; Serviceguard provides a startup script to control the startup process. Automatic cluster start is the preferred way to start a cluster. No action is required by the system administrator.

Managing the Running Cluster 223