Layered structure
An OS can be broken into pieces and retain much more control over the system. In this structure, the OS is broken into a number of layers (levels). The bottom layer (layer 0) is the hardware, and the topmost layer (layer N) is the user interface. These layers are so designed that each layer uses the functions of the lower-level layers. This simplifies the debugging process, if lower-level layers are debugged and an error occurs during debugging, then the error must be on that layer only, as the lower-level layers have already been debugged.
The main disadvantage of this structure is that at each layer, the data needs to be modified and passed on which adds overhead to the system. Moreover, careful planning of the layers is necessary, as a layer can use only lower-level layers. UNIX is an example of this structure.
Advantages of Layered Structure
- Layering makes it easier to enhance the operating system, as the implementation of a layer can be changed easily without affecting the other layers.
- It is very easy to perform debugging and system verification.
Disadvantages of Layered structure
- In this structure, the application’s performance is degraded as compared to simple structure.
- It requires careful planning for designing the layers, as the higher layers use the functionalities of only the lower layers.
Operating Systems Structures
The operating system can be implemented with the help of various structures. The structure of the OS depends mainly on how the various standard components of the operating system are interconnected and melded into the kernel.
A design known as an operating system enables user application programs to communicate with the machine’s hardware. Given its complex design and need to be easy to use and modify, the operating system should be constructed with the utmost care. A straightforward way to do this is to supernaturally develop the operating system. These parts must each have unique inputs, outputs, and functionalities.
This article discusses a variety of operating system implementation structures, including those listed below, as well as how and why they function. Additionally, the operating system structure is defined.
Depending on this, we have the following structures in the operating system:
- Simple/Monolithic Structure
- Micro-Kernel Structure
- Hybrid-Kernel Structure
- Exo-Kernel Structure
- Layered Structure
- Modular Structure
- Virtual Machines