NonStop Operations Guide for H-Series and J-Series RVUs

the system continues to run. A single NonStop system can have up to four NonStop Blade Complexes
for a total of 16 processors. Processors communicate with each other and with the system I/O over
dual ServerNet fabrics.
A ServerNet fabric is a complex web of links that provide a large number of possible paths from
one point to another. Two communications fabrics, the X and Y ServerNet fabrics, provide
redundant, fault-tolerant communications pathways. If a hardware fault occurs on one of the
ServerNet fabrics, communications continues on the other with hardware fault recovery transparent
to all but the lowest level of the OS.
Figure 4 shows one NonStop Blade Complex with four processors, the I/O hardware and the
ServerNet fabrics.
Figure 4 One NonStop Blade Complex and Four Processors
For NonStop NS16000 series systems, ServerNet communications are controlled by processor
switch (or p-switch) modules; one for each of the ServerNet fabrics (represented by X and Y
ServerNet switching blocks in Figure 4). P-switches connect input/output components to the NS-series
processors. I/O components usually tap into the ServerNet fabrics through ServerNet adapters in
IOAMs (represented by Modular I/O blocks in the diagram). These adapters provide the system
I/O to fibre channel storage devices and gigabyte Ethernet communications networks. However,
P-switches also provide connectivity for legacy I/O through I/O enclosures equipped with IOMF2s
(represented by S-Series I/O blocks in the diagram).
NonStop NS14000 series systems do not have p-switches and cannot be connected to legacy
NonStop S-series I/O enclosures. For more information, see “ServerNet Connectivity” (page 100).
In summary, these terms describe NonStop NS16000 series and NS14000 series processors:
DescriptionTermSystems and Planning Guides
Consists of two Blade Elements (in a duplex
system) or three Blade Elements (in a triplex
Blade ComplexNonStop NS16000 series systems
(2 to 16 processors per system)
system) and up to four logical processors and
NonStop NS16000 Series Planning
Guide;
Overview of Processors 123