IBM RS/6000 44P - Manual (Page 83)

The memory segment or DIMM that is deconfigured remains off-line for subsequent
reboots until the faulty memory hardware is replaced.
The function allows users to manually deconfigure or re-enable a previously
deconfigured memory segment/DIMM through the Service Processor menu. The user
can also enable or disable this function through the Service Processor menu.
Service Processor System Monitoring - Surveillance
Surveillance is a function in which the service processor monitors the system, and the
system monitors the service processor. This monitoring is accomplished by periodic
samplings called
heartbeats
Surveillance is available during two phases:
v System firmware bring-up (automatic)
v Operating system run time (optional)
System Firmware Surveillance
System firmware surveillance provides the service processor with a means to detect
boot failures while the system firmware is running.
System firmware surveillance is automatically enabled during system power-on. It
cannot be disabled by the user.
If the service processor detects no heartbeats during system boot (for 7 minutes), it
cycles the system power to attempt a reboot. The maximum number of retries is set
from the service processor menus. If the fail condition repeats, the service processor
leaves the machine powered on, logs an error, and displays menus to the user. If
Call-out is enabled, the service processor calls to report the failure and displays the
operating-system surveillance failure code on the operator panel.
Operating System Surveillance
The operating system surveillance provides the service processor with a means to
detect hang conditions, as well as hardware or software failures, while the operating
system is running. It also provides the operating system with a means to detect service
processor failure caused by the lack of a return heartbeat.
Operating system surveillance is enabled by default, allowing the user to run operating
systems that do not support this service processor option.
You can also use Service Processor Menus and Service Processor Service Aid to
enable or disable operating system surveillance.
For operating system surveillance to work correctly, you must set the following
parameters:
v Surveillance enable/disable
v Surveillance interval
Chapter 3. Using the Service Processor 65