Configuring A Failover Domain - Red Hat ENTERPRISE LINUX 5 - ADMINISTRATION Manual

3. On that page, at the Choose a taskdrop-down box, choose Delete this node and click Go. When
the node is deleted, a page is displayed that lists the nodes in the cluster. Check the list to make
sure that the node has been deleted.

3.7. Configuring a Failover Domain

A failover domain is a named subset of cluster nodes that are eligible to run a cluster service in the
event of a node failure. A failover domain can have the following characteristics:
• Unrestricted — Allows you to specify that a subset of members are preferred, but that a cluster
service assigned to this domain can run on any available member.
• Restricted — Allows you to restrict the members that can run a particular cluster service. If none
of the members in a restricted failover domain are available, the cluster service cannot be started
(either manually or by the cluster software).
• Unordered — When a cluster service is assigned to an unordered failover domain, the member on
which the cluster service runs is chosen from the available failover domain members with no priority
ordering.
• Ordered — Allows you to specify a preference order among the members of a failover domain. The
member at the top of the list is the most preferred, followed by the second member in the list, and so
on.
• Failback — Allows you to specify whether a service in the failover domain should fail back to the
node that it was originally running on before that node failed. Configuring this characteristic is useful
in circumstances where a node repeatedly fails and is part of an ordered failover domain. In that
circumstance, if a node is the preferred node in a failover domain, it is possible for a service to fail
over and fail back repeatedly between the preferred node and another node, causing severe impact
on performance.
Note
The failback characteristic is applicable only if ordered failover is configured.
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
Configuring a Failover Domain
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