Installing and Managing HP-UX Virtual Partitions (includes A.04.01)

CPU, Memory, and IO Resources
CPU: CPU Monitor (formerly known as LPMC Monitor) (vPars A.04, A.03 and earlier)
Chapter 6
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CPU: CPU Monitor (formerly known as LPMC Monitor)
(vPars A.04, A.03 and earlier)
The CPU Monitor (a part of the diagnostic tool Event Monitor Services (EMS) and not a part of the vPars
Monitor) is designed to Monitor cache parity errors within the processors on the system. With its Dynamic
Processor Resilience (DPR), If the CPU Monitor detects a pre-determined number of errors, the CPU Monitor
will deactivate a processor for the current boot session. If the problems are severe enough, the CPU Monitor
will deconfigure the socket for the next boot of the system.
Deactivation of a processor means that the OS will attempt to no longer use the processor by migrating all
threads off the processor. Deactivation of a processor is not persistent across an OS or system reboot; CPU
Monitor will deactivate the processor if it continues to detect problems.
Deconfiguration of a socket means that the EMS issues a firmware call, marking the socket for
deconfiguration on the next system boot. On the next system boot, the processors on the target socket are not
visible to either the OS in standalone mode or the OS instances of the virtual partitions. The deconfiguration
is persistent across system boots.
Note here two items:
• a deactivation of a processor does not mean a deconfiguration of its socket. The CPU Monitor is able to
determine whether the processor needs to be deactivated or whether it needs to take further action and
deconfigures the socket.
• reboot of a virtual partition is not the same as a reboot of the system (the entire box or nPartition).
The exceptions to the deactivation of processors is the boot processor of each OS instance (the boot processor
has a logical instance of zero; otherwise, the OS would crash) and the last CPU in a cell or nPartition. The
exception to the deconfiguration of sockets is that the last remaining socket will not be deconfigured
(otherwise, the system could not boot).
If any spare iCAP (formerly known as iCOD) or PPU processors are available, the necessary number of
processors will be activated to replace the processors deactivated.
NOTE (A.04) On a vPars system, when a virtual partition goes down and contains deconfigured or
deactivated CPUs, the Monitor will try to decommission the CPU from use and replace it with
another good CPU if possible. If this is not possible, the Monitor will not allow the partition to
boot until the deconfigured or deactivated CPU can be taken out of use. Following are some
cases where the Monitor may not allow the virtual partition to boot:
• There is a deconfigured or deactivated CPU which has been reserved for the partition as
part of the total (cpu::num) request and Monitor does not have any free CPUs with which
to replace it. To correct this, you can delete CPUs from other partitions or from this
partition.
• There is a deconfigured or deactivated CPU which has been bound to the partition due to
specifying the hardware path (cpu:hw_path) of which the Monitor is not able to replace
with another available CPU. To correct this, you can remove the CPU specified by hardware
path using -d cpu:hw_path to allow the deconfigured or deactivated CPU to be
decommissioned and replaced with another (working) CPU.