What is the role of NOS and DO/S in network operating systems?

[rtareen]

TL;DR Summary

Trying to understand the concept of a DO/S and how it is implemented.

I'm attaching a picture for reference. The full reference is Chapter 10 of "Understanding Operating Systems" by McHoes and Flynn., seventh edition.

I'm understanding a network operating system (NOS) to be a separate entity from the local operating system that gets the data and gives it to the local operating system to process locally on your own computer. The local operating system cannot tell the difference between local data and data obtained by the NOS. It's like a little fetch function that returns data from another node by doing the dirty work and going through the network and all its protocols. The local operating system doesn't care how the NOS got it, but just sees the data it returns. At least that's how I understood it.

But I don't understand DO/S at all. They're making it appear to be this ethereal operating system that controls all the computers in the network. I can't understand this in terms of networks such as the internet. Do all computers on the internet share an omnipresent operating system that exists throughout space in the ether? I think not and I don't know how to properly comprehend it.

Wikipedia said that a DO/S is "system software over a collection of independent software, networked, communicating, and physically separate computational nodes". They way I understand this is that it is part of the local operating system and all computers have it, and that its synchronized. But how can all computers have the exact software needed to synchronize everything when there are several manufacturers who design their operating systems differently. I don't have all the information I need for this to make sense.

 

[jedishrfu]

What may be confusing here is that DOS can mean either DISK Operating System (like PC DOS) or Distributed Operating System. They are different concepts.

A Raspberry PI with an SD card with a full image of LINUX on it is a simple standalone computer. It doesn't need a network to boot or to run.

This may help:

https://ipwithease.com/nos-vs-dos/

Basically in a NOS the computers on the network have local files and folders and have shared access to files and folders on other computers. Software development teams use networked computers to share source code e.g. GIT or SVN and software tools.

In contrast, a DOS treats the computers on the network as extensions of itself, and each computer must request access to shared resources like printers, files, and folders. When you run programs from a distributed computer, it will utilize other computers on the network to help it get the job done.

https://lemp.io/what-are-the-examples-of-distributed-operating-system/

A distributed operating system is a computer system that uses multiple computers to provide resources and services to users. This type of system is often used in large organizations where many users need access to shared resources, such as files, printers, and email servers.

There are several benefits to using a distributed operating system.

First, it can provide a higher level of availability than a single-computer system. If one computer in the system goes down, the others can still provide services to users.

Second, it can offer better performance than a single-computer system. When multiple computers are used, each can be dedicated to a specific task, such as handling email requests or serving web pages. This can lead to faster response times for users.

 

[rtareen]

Thank you for your answer and the resources.