Red Hat CLUSTER FOR ENTERPRISE LINUX 5.0, Руководство по настройке

Страница: 50 / 114

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.
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.
Tip
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 7.1, “Adding a Failover Domain”
• Section 7.2, “Modifying a Failover Domain”
Chapter 3. Configuring Red Hat Cluster With Conga
40