Instant Capacity on Demand (iCOD) User's Guide for versions B.05.x

Using iCOD to Manage your Processors
Replacement of Failed Processors
Chapter 470
Replacement of Failed Processors
In Online Activation Mode
If an active processor fails with a Low Priority Machine Check (LPMC),
in your iCOD system, its processor capacity is replaced instantly by an
inactive processor, if any are available on the system/partition. The
failing processor is marked for deconfiguration during the next system
reboot.
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 on the system/partition.
NOTE In both of the above scenarios the failed processor should be replaced in a
timely manner using your normal hardware support process.
Failed Monarch Processors
Monarch processors (see “monarch processor” on page 140 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 is
not be able to deactivate the processor, unless the system is re-booted.
Deactivation of a monarch processor is not possible because it is the
controlling processor of the operating system (CPU 0). Therefore, an
iCOD processor cannot replace a (failing) monarch processor.
If your iCOD 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 iCOD 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.