NonStop Systems Introduction for H-Series RVUs

Integrity NonStop NS-Series Server Architecture
NonStop Systems Introduction for H-Series RVUs—540083-001
7-7
Interconnected Multiple Processors
The two fabrics are identified as the X fabric and the Y fabric, and no router connects
to both the X fabric and the Y fabric. Each processor connects to a single router in
each fabric. For example, Processor 0 connects to router 5 in the X fabric and to router
1 in the Y fabric.
The use of two fabrics ensures that two paths exist between all the processors in the
system. If a path through one fabric fails, there is always another path through the
other fabric. Thus, in conjunction with the file system and message system, the
duplication of ServerNet fabrics enables processes to carry out their work by means of
a continuous exchange of messages with other processes in the system.
Figure 7-5. Dual Data Paths Between Processors
VST093.vsd
31 2
876
ServerNet Y fabric
ServerNet X fabric
Logical
Processor 1
LSU 1
PE 1
PE 1
PE 1
Logical
Processor 0
LSU 3
PE 3
PE 3
PE 3
Logical
Processor 2
LSU 2
PE 2
PE 2
PE 2
PE = Processor element
4
5
8
1
4
Logical
Processor 0
LSU 0
PE 0
PE 0
PE 0