Layered Architecture of Operating System




Layered Architecture of Operating System

Operating systems using this architecture are intended to overcome the disadvantages of monolithic systems. As a result, the OS is divided into various layers, each of which performs a different function.

It is possible for each layer to interact with both the one above it and the one below it. In general, the lowermost layer which deals directly with the bare hardware is intended to perform I/O communications, while the uppermost layer, which is directly connected to the application program, serves as an interface between the user and the operating system.

As a result of the fact that all the functionalities are on different layers, each layer can be tested and debugged independently.

The Microsoft Windows NT Operating System is a good example of the layered structure.


 

Layered Architecture of Operating System

Fig. Layered Architecture of Operating System

Advantages of Layered architecture:

  1. A malfunction in one layer will not affect the entire operating system

  2. Testing and debugging are easier due to layer isolation.

  3. The process of adding new functionalities or removing obsolete ones is very simple.

Disadvantages of Layered architecture:

  1. There are times when it is not possible to separate the functionalities, because they are often inter-related and cannot be separated.

  2. In some cases, there are a large number of functionalities and the number of layers increases significantly. The performance of the system may be affected as a result.

  3. There is no communication between layers that are not adjacent.



Frequently Asked Questions

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Ans: It is the oldest architecture of the operating system. We know that all the core software components of the operating system are collectively known as the kernel. view more..
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Ans: there are 4 types of architectures of operating system: 1. Monolithic architecture 2. Layered architecture 3. Microkernel architecture 4. Hybrid architecture view more..
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Ans: Process Implementation view more..
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Ans: This is an important architecture of operating system which is meant to overcome the disadvantages of early monolithic systems. view more..
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Ans: The basic ideology in this architecture is to keep the kernel as small as possible. We know that kernel is the core part of the operating system and hence it should be meant for handling the most important services only. view more..
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Ans: the idea was to combine the best functionalities of all old approaches and hence this design is termed as the hybrid structured operating system. view more..
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Ans: System Calls and Programs All the present-day operating systems support the following two modes of operation for the CPU: User mode Kernel mode view more..
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Ans: A batch system executes jobs, whereas a time-shared system has user programs, or tasks. Even on a single-user system such as Microsoft Windows, a user may be able to run several programs at one time: a word processor, a web browser, and an e-mail package. Even if the user can execute only one program at a time, the operating system may need to suppoft its own internal programmed activities, such as memory management. view more..
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Ans: Process scheduling selects processes from the queue and loads them into memory for execution. Process loads into the memory for CPU scheduling. The primary objective of the job scheduler is to provide a balanced mix of jobs, such as I/O bound and processor bound. ... Time-sharing operating systems have no long term scheduler. view more..




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