Installation guide

member at the top of the list is the most preferred, followed by the second member in the list, and so
on.
Note
Changing a failover domain configuration has no effect on currently running services.
Note
Failover domains are not required for operation.
By default, failover domains are unrestricted and unordered.
In a cluster with several members, using a restricted failover domain can minimize the work to set up the
cluster to run a cluster service (such as httpd), which requires you to set up the configuration
identically on all members that run the cluster service). Instead of setting up the entire cluster to run the
cluster service, you must set up only the members in the restricted failover domain that you associate
with the cluster service.
Note
To configure a preferred member, you can create an unrestricted failover domain comprising only
one cluster member. Doing that causes a cluster service to run on that cluster member primarily
(the preferred member), but allows the cluster service to fail over to any of the other members.
The following sections describe adding a failover domain and modifying a failover domain:
Section 3.7.1, “Adding a Failover Domain”
Section 3.7.2, “Modifying a Failover Domain”
3.7.1. Adding a Failover Domain
To add a failover domain, follow the steps in this section. T he starting point of the procedure is at the
cluster-specific page that you navigate to from Choose a cluster to adm inister displayed on
the cluster tab.
1. At the detailed menu for the cluster (below the clusters menu), click Failover Domains. Clicking
Failover Domains causes the display of failover domains with related services and the display of
menu items for failover domains: Add a Failover Domain and Configure a Failover Domain .
2. Click Add a Failover Domain. Clicking Add a Failover Domain causes the display of the Add
a Failover Dom ain page.
3. At the Add a Failover Dom ain page, specify a failover domain name at the Failover
Domain Name text box.
Note
The name should be descriptive enough to distinguish its purpose relative to other names
used in your cluster.
Red Hat Enterprise Linux 4 Cluster Administration
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