9.3. Managing High-Availability Services
You can manage high-availability services using the Cluster Status Utility,
clustat, and the Cluster User Service Administration Utility, clusvcadm. clustat displays the status of a cluster and clusvcadm provides the means to manage high-availability services.
This section provides basic information about managing HA services using the
clustat and clusvcadm commands. It consists of the following subsections:
9.3.1. Displaying HA Service Status with clustat
clustat displays cluster-wide status. It shows membership information, quorum view, the state of all high-availability services, and indicates which node the clustat command is being run at (Local). Table 9.1, “Services Status” describes the states that services can be in and are displayed when running clustat. Example 9.3, “clustat Display” shows an example of a clustat display. For more detailed information about running the clustat command see the clustat man page.
| Services Status | Description |
|---|---|
| The service resources are configured and available on the cluster system that owns the service. | |
| The service is pending start on another node. | |
| The service has been disabled, and does not have an assigned owner. A disabled service is never restarted automatically by the cluster. | |
| In the stopped state, the service will be evaluated for starting after the next service or node transition. This is a temporary state. You may disable or enable the service from this state. | |
The service is presumed dead. A service is placed into this state whenever a resource's stop operation fails. After a service is placed into this state, you must verify that there are no resources allocated (mounted file systems, for example) prior to issuing a disable request. The only operation that can take place when a service has entered this state is disable. | |
This state can appear in certain cases during startup and running clustat -f. |
Example 9.3. clustat Display
[root@example-01 ~]#clustat
Cluster Status for mycluster @ Wed Nov 17 05:40:15 2010
Member Status: Quorate
Member Name ID Status
------ ---- ---- ------
node-03.example.com 3 Online, rgmanager
node-02.example.com 2 Online, rgmanager
node-01.example.com 1 Online, Local, rgmanager
Service Name Owner (Last) State
------- ---- ----- ------ -----
service:example_apache node-01.example.com started
service:example_apache2 (none) disabled
