HP Instant Capacity User's Guide for versions B.07.x

Using Instant Capacity to Manage Processing Capacity
Replacement of Failed Processors
Chapter 4 71
Replacement of Failed Processors
LPMC and HPMC
If an active processor fails with a Low Priority Machine Check (LPMC),
in a partition with Instant Capacity, its processor capacity is replaced
instantly by an inactive processor, if any are available in the partition.
The failed processor is marked for deconfiguration during the next
system reboot.
See “LPMC Deactivations in Virtual Partitions” on page 140 for
additional considerations in a virtual partition environment.
If an active processor fails with a High Priority Machine Check (HPMC),
then upon reboot, the failed processor is deconfigured and its processor
capacity is instantly replaced by an inactive processor, if any are
available in the partition.
NOTE In both of the above scenarios, you should replace the failed processor in
a timely manner using your normal hardware support process.
Failed Monarch Processors
Monarch processors (see page 157 for a definition) 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, Instant Capacity 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.