Disabling Resources

Disabling a resource means that the resource is no longer monitored by a VCS agent, and that the resource cannot be brought online or taken offline. The agent starts monitoring the resource after the resource is enabled. The resource attribute Enabled determines whether a resource is enabled or disabled. (See Resource Attributes for details.) A persistent resource can be disabled when all its parents are offline. A non-persistent resource can be disabled when the resource is in an OFFLINE state.

When to Disable a Resource

Typically, resources are disabled when one or more resources in the service group encounter problems and disabling the resource is required to keep the service group online or to bring it online.

  To disable a resource

To disable the resource when VCS is running:

To have the resource disabled initially when VCS is started, set the resource's Enabled attribute to 0 in main.cf.

Limitations

When VCS is running, there are certain prerequisites to be met before the resource is disabled successfully.

  An online non-persistent resource cannot be disabled. It must be in a clean OFFLINE state. (The state must be OFFLINE and IState must be NOT WAITING.)

  If it is a persistent resource and the state is ONLINE on some of the systems, all dependent resources (parents) must be in clean OFFLINE state. (The state must be OFFLINE and IState must be NOT WAITING)

Therefore, before disabling the resource you may be required to take it offline (if it is non-persistent) and take other resources offline in the service group.

Additional Considerations

• When a group containing disabled resources is brought online, the online transaction is not propagated to the disabled resources. Children of the disabled resource are brought online by VCS only if they are required by another enabled resource.
• You can bring children of disabled resources online if necessary.
• When a group containing disabled resources is taken offline, the offline transaction is propagated to the disabled resources.

The following figures show how a service group containing disabled resources is brought online.

Click the thumbnail above to view full-sized image.

In the figure above, Resource_3 is disabled. When the service group is brought online, the only resources brought online by VCS are Resource_1 and Resource_2 (Resource_2 is brought online first) because VCS recognizes Resource_3 is disabled. In accordance with online logic, the transaction is not propagated to the disabled resource.

In the figure below, Resource_2 is disabled. When the service group is brought online, resources 1, 3, 4 are also brought online (Resource_4 is brought online first). Note Resource_3, the child of the disabled resource, is brought online because Resource_1 is enabled and is dependent on it.

Click the thumbnail above to view full-sized image.

How Disabled Resources Affect Group States

When a service group is brought online containing non-persistent, disabled resources whose AutoStart attributes are set to 1, the group state is PARTIAL, even though enabled resources with Autostart=1 are online. This is because the disabled resource is considered for the group state.

To have the group in the ONLINE state when enabled resources with AutoStart set to 1 are in ONLINE state, set the AutoStart attribute to 0 for the disabled, non-persistent resources.