Hardware Failure 
Description 
Failure Behavior If 
HACMP Is Not 
Configured
 
Extra Work Required 
To Provide Recovery 
Action (in addition to 
normal HACMP 
configuration)
 
Recovery Action and Behavior If 
HACMP Is Configured 
Node Outage or AIX 
crash
 
Node unavailable  None  HACMP fallover. Application(s) 
unavailable for brief time during 
fallover.
 
Ethernet adapter failure  Access to node through 
Ethernet lost, error log 
entry.
 
None  HACMP swap adapter event moves 
IP address to spare adapter. Node 
Ethernet IP address unavailable for 
an extremely brief period as address 
is swapped.
 
SSA Drawer Power 
Supply Failure 
None seen, error log 
entry 
None  N/A (no fallover) 
SSA adapter failure¹  None seen, error log 
entry 
None  N/A (no fallover) 
CPU power supply or 
cooling subsystem 
failure
 
Node available, N+1 
redundancy 
None  N/A (no fallover) 
CPU power cord or 
power supply circuit 
failure
 
Node unavailable  None  HACMP fallover, application(s) 
unavailable for a brief time during 
fallover.
 
I/O drawer power supply 
or cooling subsystem 
failure
 
Node available, N+1 
redundancy 
None  N/A (no fallover) 
I/O drawer power cord 
failure 
Fallover does not 
happen if the redundant 
power supplies are 
cabled to separate I/O 
rack power distribution 
units that are powered 
by different supply 
circuits.
 
None  N/A (no fallover). 
I/O power distribution 
unit power cord failure. 
None  None  N/A (no fallover). 
  
 ¹ Assumes “Quorum off” for volume group. 
High Availability Cluster Server System Cabling 
This section provides cabling information for the base HA cluster server. Ensure that the two systems are 
installed before cabling the HA cluster server. Consider the following cable areas to ensure the redundancy 
required for no single points of failure: 
v   Cabling for server system consoles and cluster administration workstations 
v   Heartbeat connections between HA cluster servers 
v   SSA cable connections between HA cluster servers and 7133 Serial Disk Subsystems 
v   Power cable connections
Cabling For System Consoles and Cluster Administration Workstations 
The system console for a High Availability Cluster Server can be either of the following: 
v   an ASCII terminal connection to the S1 serial port 
 
 
368  Site and Hardware Planning Information