Specifications

Chapter 4. Continuous availability and manageability 117
Draft Document for Review May 12, 2014 12:46 pm 5102ch04.fm
mechanisms, extending from processor cores and memory to power supplies and hard
drives.
Service processor
The service processor is a microprocessor that is powered separately from the main
instruction processing complex. The service processor provides the capabilities for the
following items:
򐂰 POWER Hypervisor (system firmware) and Hardware Management Console connection
surveillance
򐂰 Several remote power control options
򐂰 Reset and boot features
򐂰 Environmental monitoring
The service processor monitors the server’s built-in temperature sensors, sending
instructions to the system fans to increase rotational speed when the ambient temperature is
above the normal operating range. By using an architected operating system interface, the
service processor notifies the operating system of potential environmentally related problems
so that the system administrator can take appropriate corrective actions before a critical
failure threshold is reached. The service processor can also post a warning and initiate an
orderly system shutdown in the following circumstances:
򐂰 The operating temperature exceeds the critical level (for example, failure of air
conditioning or air circulation around the system).
򐂰 The system fan speed is out of operational specification (for example, because of multiple
fan failures).
򐂰 The server input voltages are out of operational specification.
The service processor can immediately shut down a system in the following circumstances:
򐂰 Temperature exceeds the critical level or remains above the warning level for too long.
򐂰 Internal component temperatures reach critical levels.
򐂰 Non-redundant fan failures occur.
The service processor provides the following features:
򐂰 Placing calls
On systems without a Hardware Management Console, the service processor can place
calls to report surveillance failures with the POWER Hypervisor, critical environmental
faults, and critical processing faults even when the main processing unit is inoperable.
򐂰 Mutual surveillance
The service processor monitors the operation of the firmware during the boot process, and
also monitors the hypervisor for termination. The hypervisor monitors the service
processor and can perform a reset and reload if it detects the loss of the service
processor. If the reset/reload operation does not correct the problem with the service
processor, the hypervisor notifies the operating system; the operating system can then
take appropriate action, including calling for service.
򐂰 Availability
The POWER8 family of systems continues to offer and introduce significant
enhancements designed to increase system availability.
As in POWER6, POWER6+, POWER7, POWER7+, and the POWER8 processor has the
ability to do processor instruction retry and alternate processor recovery for several
core-related faults. This ability significantly reduces exposure to both hard (logic) and soft