HP Serviceguard Cluster Configuration for HP-UX 11i or Linux Partitioned Systems, April 2009

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the possibility of a complete cluster failure. This configuration is discussed in the section “Cluster in a
box.”
Figure 3. Unsupported configuration
Rule 2. Configurations containing the potential for a loss of exactly 50% of the membership resulting
from a single failure require the use of quorum arbitration. This includes:
• Cluster configurations where the nodes are running in partitions or virtual machines that are wholly
contained within and equally divided between two hardware cabinets
• Cluster configurations where the nodes are running as vPars partitions or virtual machines that are
wholly contained within and equally divided between two nPartitions.
• Cluster configurations where the half the nodes are running in a single hardware cabinet.
For example, to be supported, a four-node cluster consisting of two nPartitions in each of two
Superdome cabinets would require a quorum arbitration device. In figure 4, there are two
Superdomes, each with two partitions. Each partition is running one package. In this example the
quorum arbitration is provided by a quorum server.