NonStop S-Series Operations Guide (G06.27+)

Processors: Monitoring and Recovery
HP NonStop S-Series Operations Guide—522459-008
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Identifying Processor Problems
Identifying Processor Problems
Abnormal processor states include hardware error freezes, system hangs, and
processor halts.
Hardware Error Freezes
A hardware error freeze occurs when a processor cannot continue processing due to
the risk of using corrupt data from a hardware error. Contact your service provider
before dumping a frozen processor. The PMF CRU containing the frozen processor,
including its memory units, might need to be replaced.
Processor Hangs
A processor hang occurs when system components wait for an event that is not going
to happen. An unexpected event such as a deadlock (two or more processors waiting
for each other) might have occurred.
Processor Halts
When certain errors occur (such as when data integrity is at risk), the operating system
cannot correct the problem and must halt all application and system processes running
in the associated processor. The remaining running processors in the system each
send a message, reporting the halted processor as down. The other processors in the
system, including the backup to the halted processor, are not affected by the errors
that caused the processor to halt unless they are freeze-enabled.
Two types of processor halts display a processor halt code in the Processor Status
dialog box:
•
A halt instruction results in a processor halt.
When the operating system detects a millicode or software error that it cannot
correct, it can execute a halt instruction to suspend all application and system
processes running in the associated processor. The status of the halted processor
becomes:
Halt code = %nnnnnn
Unlike a freeze instruction, a halt instruction affects only one processor.
•
A processor can be halted by a freeze instruction.
A freeze-enabled processor can be frozen by another frozen processor. When a
freeze instruction is executed, any processors that are freeze-enabled also freeze
immediately. When the operating system detects a software error that it cannot
correct, it can execute a freeze instruction to suspend all application and system
processes running in the associated processor. The status of the frozen processor
becomes:
Freeze code = %nnnnnn