Setting Start, Failover, And Failback Modes For Cluster Resources; Monitoring Services Critical To Clustering; Understanding Cluster Resource Modes - Novell OPEN ENTERPRISE SERVER 2 SP 2 - CLUSTER SERVICES 1.8.7 FOR LINUX Manual

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Monitoring scripts can also be used for monitoring critical services needed by the resources, such as

Linux User Management (namcd) and Novell eDirectory (ndsd). However, the monitoring is in

effect only where the cluster resource is running.

IMPORTANT: The monitor script runs only on the cluster server where the cluster resource is

currently online. The script does it monitor the critical services on its assigned cluster server when

the resource is offline. The monitor script does not monitor critical services for any other cluster

node.

For example, to monitor whether the namcd and ndsd services are running, add the following

commands to the Monitor script:

# (optional) status of the eDirectory service

exit_on_error rcndsd status

# (optional) status of the Linux User Management service

exit_on_error namcd status

9.7 Setting Start, Failover, and Failback Modes

for Cluster Resources

You can configure the start, failover, and failback of cluster resources to happen manually or

automatically.

IMPORTANT: Cluster Services works with NCP user connections so that the user data sessions are

resumed after failover. However, non-NCP users might experience service interruption and need to

reconnect to the server after the failover. Applications using server based storage must be restarted

on the client even with NCP unless they are NCP reconnect aware.

Section 9.7.1, "Understanding Cluster Resource Modes," on page 125

Section 9.7.2, "Viewing or Modifying the Start, Failover, and Failback Modes for a Resource,"

on page 126

With the resource Start mode set to AUTO, the resource automatically starts on a server when the

cluster is first brought up. If the resource Start mode is set to MANUAL, you can manually start the

resource on a server when you want, instead of having it automatically start when servers in the

cluster are brought up.

With the resource Failover mode set to AUTO, the resource automatically starts on the next server

in the Assigned Nodes list in the event of a hardware or software failure. If the resource Failover

mode is set to MANUAL, you can intervene after a failure occurs and before the resource is moved

to another node.

With the resource Failback mode set to DISABLE, the resource does not fail back to its most

preferred node when the most preferred node rejoins the cluster. If the resource Failback mode is set

to AUTO, the resource automatically fails back to its most preferred node when the most preferred

Configuring and Managing Cluster Resources 125

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Troubleshooting