Red Hat Cluster Suite, Руководство пользователя

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56 Chapter 3. Installing and Configuring Red Hat Cluster Suite Software
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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.
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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).
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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.
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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.
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 compris-
ing 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, removing a failover domain, and
removing members from a failover domain:
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Section 3.8.1 Adding a Failover Domain
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Section 3.8.2 Removing a Failover Domain
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Section 3.8.3 Removing a Member from a Failover Domain
3.8.1. Adding a Failover Domain
To add a failover domain, follow these steps:
1. At the left frame of the the Cluster Configuration Tool , click Failover Domains .