Ensure that all prerequisites are complete before using
the wizard to create a resource group to make resources available
to a cluster.
After the resources are ready for use by PowerHA® SystemMirror, you can assign
related resources to resource groups for easier management as single
entities. For example, if an application depends on one or more volume
groups and service IP addresses, you can place these resources in
a single resource group. You then can manage them as one unit.
The following general rules and restrictions apply to resources
and resource groups:
- You add a resource group to a cluster. Therefore at least one
cluster must be configured before you can configure and add a resource
group.
- Cluster resources must be part of a resource group in order for PowerHA SystemMirror to keep the
resources highly available. If you want a resource to be kept separate,
define a group for that resource alone. A resource group can have
one or more resources defined.
- Components of a resource group must be unique. Put the application,
along with the resources it requires, in the same resource group.
- The service IP labels, volume group names, and resource group
names must be unique within the cluster and must be distinct from
each other. Provide names that make it easy to determine that the
resource is associated with the application that uses it, and to any
corresponding device. For example, you might specify a name of appX_service_address for
a service IP label to assign to application X.
- If a node participates in more than one resource group, ensure
that the node has the memory, network interfaces, and other items,
that the node requires to manage all resource groups simultaneously.