Red Hat ENTERPRISE LINUX 5 - GLOBAL NETWORK BLOCK DEVICE Guide d'installation télécharger pdf (Page 118)

• Section 5, “Debugging and Testing Services and Resource Ordering”

Note

The sections that follow present examples from the cluster configuration file,

/etc/cluster/cluster.conf, for illustration purposes only.

1. Parent, Child, and Sibling Relationships Among

Resources

A cluster service is an integrated entity that runs under the control of rgmanager. All resources

in a service run on the same node. From the perspective of rgmanager, a cluster service is one

entity that can be started, stopped, or relocated. Within a cluster service, however, the hierarchy

of the resources determines the order in which each resource is started and stopped.The

hierarchical levels consist of parent, child, and sibling.

Example D.1, “Resource Hierarchy of Service foo” shows a sample resource tree of the service

foo. In the example, the relationships among the resources are as follows:

• fs:myfs (<fs name="myfs" ...>) and ip:10.1.1.2 (<ip address="10.1.1.2 .../>) are siblings.

• fs:myfs (<fs name="myfs" ...>) is the parent of script:script_child (<script

name="script_child"/>).

• script:script_child (<script name="script_child"/>) is the child of fs:myfs (<fs

name="myfs" ...>).

</fs>

</service>

Example D.1. Resource Hierarchy of Service foo

The following rules apply to parent/child relationships in a resource tree:

• Parents are started before children.

Appendix D. HA Resource Behavior

108

1 2 ... 113 114 115 116 117 118 119 120 121 122 123 ... 133 134

Pas de commentaire

Red Hat ENTERPRISE LINUX 5 - GLOBAL NETWORK BLOCK DEVICE Guide d'installation Page 118