The Cluster Configuration Tool automatically retains backup copies of the three most recently used configuration files (besides the currently used configuration file). Retaining the backup copies is useful if the cluster does not function correctly because of misconfiguration and you need to return to a previous working configuration.
Each time you save a configuration file, the Cluster Configuration Tool saves backup copies of the three most recently used configuration files as /etc/cluster/cluster.conf.bak.1, /etc/cluster/cluster.conf.bak.2, and /etc/cluster/cluster.conf.bak.3. The backup file /etc/cluster/cluster.conf.bak.1 is the newest backup, /etc/cluster/cluster.conf.bak.2 is the second newest backup, and /etc/cluster/cluster.conf.bak.3 is the third newest backup.
If a cluster member becomes inoperable because of misconfiguration, restore the configuration file according to the following steps:
At the Cluster Configuration Tool tab of the Red Hat Cluster Suite management GUI, click File => Open.
Clicking File => Open causes the system-config-cluster dialog box to be displayed.
At the the system-config-cluster dialog box, select a backup file (for example, /etc/cluster/cluster.conf.bak.1). Verify the file selection in the Selection box and click OK.
Increment the configuration version beyond the current working version number as follows:
Click Cluster => Edit Cluster Properties.
At the Cluster Properties dialog box, change the Config Version value and click OK.
Click File => Save As.
Clicking File => Save As causes the system-config-cluster dialog box to be displayed.
At the the system-config-cluster dialog box, select /etc/cluster/cluster.conf and click OK. (Verify the file selection in the Selection box.)
Clicking OK causes an Information dialog box to be displayed. At that dialog box, click OK.
Propagate the updated configuration file throughout the cluster by clicking Send to Cluster.
The Cluster Configuration Tool does not display the Send to Cluster button if the cluster is new and has not been started yet, or if the node from which you are running the Cluster Configuration Tool is not a member of the cluster. If the Send to Cluster button is not displayed, you can still use the Cluster Configuration Tool; however, you cannot propagate the configuration. You can still save the configuration file. For information about using the Cluster Configuration Tool for a new cluster configuration, refer to Chapter 3 Installing and Configuring Red Hat Cluster Suite Software.
Clicking Send to Cluster causes a Warning dialog box to be displayed. Click Yes to propagate the configuration.
Click the Cluster Management tab and verify that the changes have been propagated to the cluster members.