Compaq ProLiant DL380 Quick Install Manual page 14

1-4 Compaq ProLiant Clusters for SCO UnixWare 7 U/300 Quick Install Guide for the Compaq ProLiant DL380
Cluster Integrity Serial Cable
The Cluster Integrity (CI) serial cable listed with the server components is
required for the U/300 Quick Install cluster for the ProLiant DL380 server.
This cable prevents the condition in which more than one node in a cluster acts
as the root node and operates as the root node. Because the active root node
mounts the root file system and runs several critical cluster-wide functions,
more than one node trying to behave as the root node is undesirable.
NOTE: The CI serial cable may be referred to as the split-brain avoidance (SBA) serial
cable in UnixWare software and documentation.
Hardware Configuration
The U/300 kit for the ProLiant DL380 server supports the server and storage
hardware in specific configurations based on the type of cluster interconnect.
The CI serial cable is required for all configurations.
A ServerNet I cluster interconnect uses the two ServerNet I PCI adapters and
two cables as shown in Figure 1-1.
Figure 1-1. Example of hardware components of the ServerNet I cluster
interconnect configuration
Node 1
CI Serial Cable
Dedicated
ServerNet Cables
Node 2
RA4100