Fault-Tolerant Hardware - NEC Express5800 320La User Manual

As application requirements increase, you can expand your server system with
additional processors, additional memory, add-in boards and peripheral devices.
Your server system features the following major components:
Up to two high-performance 800 MHz Pentium III processors in a CPU module.
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Up to 2 GB of Synchronous Dynamic Random-Access (SDRAM) system memory in
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a CPU module.
Four PCI expansion slots, which support 32 bit PCI adapter cards in a PCI module.
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Fault-Tolerant Hardware

The hardware architecture of the system provides fault tolerance transparency. If a
hardware component fails, the application program continues processing and is never
aware that a failure occurred.
To provide system redundancy this system uses dual hardware technology. That means
that all major components are mirrored within a single hardware chassis. Group #1 is on
the left-hand side of the chassis and Group #2 is on the right-hand side of the chassis, as
viewed from the front of the chassis, see Figure 1-3. There are two CPU modules and
each CPU module is operating in lockstep (performing the same instructions at the
same time) with the other as a single system. Thus, if a failure occurs in one CPU
module the other CPU module will continue to operate with no interruption, no loss of
data, and system performance is not affected. Note that the PCI module, PCI adapters,
and power supplies are also paired for system redundancy.
Figure 1-3. Dual Hardware Fault-Tolerant Tower-Based System
1-4 System Overview
Group #2
Group #1