Managing Serviceguard 12th Edition, March 2006

Serviceguard at a Glance
What is Serviceguard?
Chapter 124
Figure 1-2 Typical Cluster After Failover
After this transfer, the failover package typically remains on the
adoptive node as long the adoptive node continues running. If you wish,
however, you can configure the package to return to its primary node as
soon as the primary node comes back online. Alternatively, you may
manually transfer control of the package back to the primary node at the
appropriate time.
Figure 1-2 does not show the power connections to the cluster, but these
are important as well. In order to remove all single points of failure from
the cluster, you should provide as many separate power circuits as
needed to prevent a single point of failure of your nodes, disks and disk
mirrors. Each power circuit should be protected by an uninterruptible
power source. For more details, refer to the section on “Power Supply
Planning” in Chapter 4, “Planning and Documenting an HA Cluster.”
Serviceguard is designed to work in conjunction with other high
availability products, such as Mirrordisk/UX or VERITAS Volume
Manager, which provide disk redundancy to eliminate single points of
failure in the disk subsystem; Event Monitoring Service (EMS), which
lets you monitor and detect failures that are not directly handled by