17.1.1 HA terms

The following table lists and defines some common HA terms.

Table 17‒2: Common HA terms
Term	Description
HA resource group	A group of resources running in a cluster environment (under an HA product).
Volume group	One or more disk drives that are configured to form a single large storage area.
Logical volume	An arbitrary-size space in a volume group that can be used as a separate file system or as a device swap space.
Primary cluster node	The first system on which the software product is installed, and the first system on which HA is configured. The shared disk is mounted on the primary cluster node for initial setup. The primary cluster node generally becomes the first active cluster node, but you do not need to maintain the primary designation after HA configuration is complete. The next time you update the HA configuration, another node might become the primary cluster node.
Secondary cluster node	Any system that is added to the HA configuration after the primary cluster node has been fully configured for HA.
Active cluster node	The system that is currently running the HA resource group.
Passive cluster node	Any system that is configured for HA but is not currently running the HA resource group. If the active cluster node fails, the HA resource group fails over to one of the available passive cluster nodes, which then becomes the active cluster node for that HA resource group.