28 IBM Certification Study Guide AIX HACMP
withdraw the 7135 RAIDiant Systems from marketing because it is equally
possible to configure RAID on the SSA Subsystems.
2.4 Resource Planning
HACMP provides a highly available environment by identifying a set of
cluster-wide resources essential to uninterrupted processing, and then
defining relationships among nodes that ensure these resources are
available to client processes.
When a cluster node fails or detaches from the cluster for a scheduled
outage, the Cluster Manager redistributes its resources among any number of
the surviving nodes.
HACMP considers the following as resource types:
• Volume Groups
• Disks
• File Systems
• File Systems to be NFS mounted
• File Systems to be NFS exported
• Service IP addresses
• Applications
The following paragraphs will tell you what to consider when configuring
resources to accomplish the following:
• IP Address Takeover
• Shared LVM Components
• NFS Exports
and the options you have when combining these resources to a resource
group.
2.4.1 Resource Group Options
Each resource in a cluster is defined as part of a resource group. This allows
you to combine related resources that need to be together to provide a
particular service. A resource group also includes the list of nodes that can
acquire those resources and serve them to clients.
A resource group is defined as one of three types: