4.3.2.2 CPU Module and Memory
When memory is deconfigured from the system, it is done by removing the CPU
module on which the memory resides.
Table 4–8 describes the OpenVMS operating system actions taken when a CPU
module or memory is identified as the FRU and is deconfigured by the EHS.
These actions are identical for CPU and memory failures. Some actions are
dependent on the system operating mode.
Table 4–8 CPU Deconfiguration Actions
Action Taken
Description
Comments
Cross-link mode =
Degraded Duplex
The cross-link mode is set to master
on the zone with the surviving CPU
and slave on the zone with the failed
CPU. The action may be taken by the
hardware when the error occurs or by
software while handling the error.
Done in Duplex mode
only.
CPU/MEM fault
A CPU/MEM fault is forced on the failed
CPU module. This results in an entry
into system console.
Set CPU LED
indicator
The module I2C bus is used to turn on
the LED indicator for the failed CPU
module.
Set module status
in CPU NVRAM
and DCB
The status_os and status_sum fields
in the module ID NVRAM and DCB
are updated to indicate the module has
experienced a failure. The code written
depends on the failure type.
When one CPU is in use (Degraded Duplex, Simplex, or Resynch mode), excessive
transient failures will result in the EHS calling out the failed module, but not
removing it from service. Removing it from service would cause termination of
the OpenVMS operating system. In this case, the CPU module LED is turned
on, and the module status is written to the CPU module NVRAM and DCB. The
OpenVMS operating system continues to run. The CPU will not be configured
when the system is booted or when the failed zone is synchronized unless the
CPU is repaired.
4.3.2.3 I/O Expansion Module
Table 4–9 describes the actions taken by the OpenVMS operating system when
an I/O expansion module is identified as the FRU and is deconfigured by the
OpenVMS operating system.
4–14 Error Handling and Analysis