Service Processor Reboot/Restart Policy ControlsThe operating system’s automatic restart policy (see operating system documentation)defines the operating system’s response to a system crash. The service processor canbe instructed to refer to that policy by the Use OS-Defined Restart Policy setup menu.Processor Boot-Time Deconfiguration (CPU Repeat Gard)Processor boot time deconfiguration allows for the removal of processors from thesystem configuration at boot time. The objective is to minimize system failure or dataintegrity exposure due to a faulty processor.This function uses processor hardware built-in self-test (BIST) and firmware power-onself-test (POST) to discover and isolate processor hardware failures during boot time. Italso uses the hardware error detection logic in the processor to capture run-timerecoverable and irrecoverable errors. The firmware uses the error signatures in thehardware to analyze and isolate the error to a specific processor.The processors that are deconfigured remain off-line for subsequent reboots until thefaulty processor hardware is replaced.This function allows users to manually deconfigure or re-enable a previouslydeconfigured processor through the service processor menu. The user can also enableor disable this function through the service processor.Processor Run-Time Deconfiguration (CPU-Gard)Processor run-time deconfiguration allows for the dynamic removal of CPUs from thesystem configuration. The objective is to minimize system failures or data integrityexposures due to a faulty processor. The processor to be removed is the one that hasexperienced repeated run-time recoverable internal errors (over a predefined threshold).The function uses the hardware error detection logic in the processor to capturerun-time recoverable errors. The firmware uses the error signatures in the hardware toanalyze and isolate the error to a specific CPU. The firmware also maintainserror-threshold information.When the number of internal recoverable errors for a processor reaches a predefinedthreshold, the firmware notifies the AIX operating system. The AIX operating systemmigrates all software processes and interrupts to another processor and puts the faultyprocessor in stop state.CPUs that are deconfigured at run time remain off-line for subsequent reboots throughthe CPU Boot Time Deconfiguration function, until the faulty CPU hardware is replaced.The user can also enable or disable this function via the AIX system managementfunction.Chapter 7. Using the Service Processor 177
