HP Instant Capacity User's Guide for Versions 8.x

Replacement of Failed Cores
HP-UX LPMC and HPMC
If an active core fails with a Low Priority Machine Check (LPMC) in a partition with Instant
Capacity, its processing capacity is replaced instantly by an inactive core, if any are available in
the partition. The failed core is marked for deconfiguration during the next system reboot.
See “LPMC Deactivations in Virtual Partitions” (page 183) for additional considerations in a
virtual partition environment.
If an active core fails with a High Priority Machine Check (HPMC), then upon reboot, the failed
core is deconfigured and its processing capacity is instantly replaced by an inactive core, if any
are available in the partition.
NOTE: In both of the above scenarios, you should replace the failed core in a timely manner
using your normal hardware support process.
Failed Monarch Processors (HP-UX only)
Monarch processors that are failing with a LPMC are not instantly replaced. When a monarch
processor experiences a LPMC, the LPMC monitor marks the processor for deconfiguration;
however, the LPMC monitor cannot deactivate the processor, unless the system is rebooted.
Deactivation of a monarch processor is not possible because it is the controlling processor of the
operating system (CPU 0). Therefore, the system cannot replace a (failing) monarch processor.
If your system has only one active processor, it is considered a monarch processor, and it cannot
be replaced online. A reboot of the system is required to replace the failing monarch processor.
If there are multiple active processors in your system, one of them is designated as the monarch
processor, and the other (non-monarch) processors can be replaced online. If the monarch
processor fails, it cannot be replaced without a reboot.
Replacement of Failed Cores on OpenVMS
If a core is experiencing correctable errors, it should be shut down and another iCAP core started
up, thereby keeping the active core count constant.
If a core experiences a fatal problem leading to a system crash, upon reboot another iCAP core
can be started thereby replacing the failed core and keeping the active core count constant.
Failed OpenVMS Primary Processors
An OpenVMS primary processor that is failing cannot be instantly replaced.
If your system has only one active processor, it is considered a primary processor and it cannot
be replaced online. A reboot of the system is required to replace the failing primary processor.
If there are multiple active processors in your system, one of them is designated as the primary
processor and the other (non-primary) processors can be replaced online. If the primary processor
fails, it cannot be replaced without a reboot.
Replacement of Failed Cores 71