HP Instant Capacity User's Guide for versions 8.x > Chapter 4 Using
Instant Capacity to Manage Processing CapacityReplacement of Failed Cores
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” 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.
Monarch processors (see Title not available 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. 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. 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. 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. |