NonStop Systems Introduction

NonStop Server Architecture
NonStop Systems Introduction—527825-001
7-2
Fault Tolerance of NonStop Servers
As shown in Figure 7-2, input/output components also tap into the ServerNet fabrics.
Quite commonly, this tapping into the ServerNet fabrics occurs through ServerNet
adapters. (A special kind of ServerNet adapter, called the multifunction I/O board,
provides convenient ServerNet interfacing for the most commonly used peripherals.)
The ServerNet adapters handle all I/O devices such as disk drives, tape drives, and
workstations.
The entire system is easily networked with other NonStop systems because all
systems use the same message system and the same network software—even
though the internal hardware architecture might differ from one series of servers to
another.
Fault Tolerance of NonStop Servers
The hardware, operating system, and application environment of NonStop servers
work together to meet all the demanding requirements of a zero latency enterprise,
such as fault tolerance, system expandability, and high performance.
None of these requirements is more important than fault tolerance, and the hardware
architecture is especially designed to achieve fault tolerance for applications.
Figure 7-2. Hardware Architecture of NonStop Servers
Processor 0 Processor 1 Processor 2 Processor 3
ServerNet
adapter
Dual ServerNet fabrics
Disks
ServerNet
adapter
ServerNet
adapter
VST091.vsd