NonStop Systems Introduction for H-Series RVUs

The NonStop Operating System
NonStop Systems Introduction for H-Series RVUs—540083-001
6-9
Distribution of Control
one processor might need to communicate with a workstation attached to another
processor and with a disk drive controlled by a disk process in yet another processor.
Figure 6-5 illustrates the requirements of the situation. The user process in Processor
1 needs to communicate with a terminal process in Processor 2 and a disk process in
Processor 0. How is this interprocess communication across processor boundaries to
be accomplished?
To resolve the problem, the original designers decided that the operating system
should be a message-based system. With such a system, one process could request
the services of other processes (such as I/O processes) anywhere in the system.
Figure 6-5. Multiple Processes in Multiple Processors
Dual ServerNet
Fabrics
Disk
process
Processor 0
User
process
Processor 1
Terminal
process
Processor 2
ServerNet
adapter
VST075.vsd
ServerNet
adapter
ServerNet
adapter