8.5. Configuring HA Services Configuring HA (High Availability) services consists of configuring resources and assigning them to services. The following sections describe how to edit /etc/cluster/cluster.conf to add resources and services. Section 8.5.1, "Adding Cluster Resources" Section 8.5.2, "Adding a Cluster Service to the Cluster" Important There can be a wide range of configurations possible with High Availability resources and services. For a better understanding about resource parameters and resource behavior, see Appendix B, HA Resource Parameters and Appendix C, HA Resource Behavior . For optimal performance and to ensure that your configuration can be supported, contact an authorized Red Hat support representative. 8.5.1. Adding Cluster Resources You can configure two types of resources: Global - Resources that are available to any service in the cluster. These are configured in the resources section of the configuration file (within the rm element). Service-specific - Resources that are available to only one service. These are configured in each service section of the configuration file (within the rm element). This section describes how to add a global resource. For procedures about configuring service-specific resources, refer to Section 8.5.2, "Adding a Cluster Service to the Cluster" . To add a global cluster resource, follow the steps in this section. Open /etc/cluster/cluster.conf at any node in the cluster. Add a resources section within the rm element. For example: Populate it with resources according to the services you want to create. For example, here are resources that are to be used in an Apache service. They consist of a file system ( fs ) resource, an IP ( ip ) resource, and an Apache ( apache ) resource. Example 8.9, " cluster.conf File with Resources Added " shows an example of a cluster.conf file with the resources section added. Update the config_version attribute by incrementing its value (for example, changing from config_version="2" to config_version="3" ). Save /etc/cluster/cluster.conf . (Optional) Validate the file against the cluster schema ( cluster.rng ) by running the ccs_config_validate command. For example: Run the cman_tool version -r command to propagate the configuration to the rest of the cluster nodes. Verify that the updated configuration file has been propagated. Proceed to Section 8.5.2, "Adding a Cluster Service to the Cluster" . Example 8.9. cluster.conf File with Resources Added

Commands:
<rm> <resources> </resources> </rm>
<rm> <resources> <fs name="web_fs" device="/dev/sdd2" mountpoint="/var/www" fstype="ext3"/> <ip address="127.143.131.100" monitor_link="yes" sleeptime="10"/> <apache config_file="conf/httpd.conf" name="example_server" server_root="/etc/httpd" shutdown_wait="0"/> </resources> </rm>
ccs_config_validate Configuration validates
<cluster name="mycluster" config_version="3"> <clusternodes> <clusternode name="node-01.example.com" nodeid="1"> <fence> <method name="APC"> <device name="apc" port="1"/> </method> </fence> </clusternode> <clusternode name="node-02.example.com" nodeid="2"> <fence> <method name="APC"> <device name="apc" port="2"/> </method> </fence> </clusternode> <clusternode name="node-03.example.com" nodeid="3"> <fence> <method name="APC"> <device name="apc" port="3"/> </method> </fence> </clusternode> </clusternodes> <fencedevices> <fencedevice agent="fence_apc" ipaddr="apc_ip_example" login="login_example" name="apc" passwd="password_example"/> </fencedevices> <rm> <failoverdomains> <failoverdomain name="example_pri" nofailback="0" ordered="1" restricted="0"> <failoverdomainnode name="node-01.example.com" priority="1"/> <failoverdomainnode name="node-02.example.com" priority="2"/> <failoverdomainnode name="node-03.example.com" priority="3"/> </failoverdomain> </failoverdomains> <resources> <fs name="web_fs" device="/dev/sdd2" mountpoint="/var/www" fstype="ext3"/> <ip address="127.143.131.100" monitor_link="yes" sleeptime="10"/> <apache config_file="conf/httpd.conf" name="example_server" server_root="/etc/httpd" shutdown_wait="0"/> </resources> </rm> </cluster>