Difference between Monolithic and layered Operating System

In this article, you will learn the difference between monolithic and layered operating systems. But before discussing this, you must know about monolithic and layered operating systems with their advantages and disadvantages.

What is the Monolithic Operating System?

It is a very simple operating system in which file management, device management, process management, and memory management are all controlled directly from the kernel. All of these components, including file management and memory management, are located within the kernel.

It is also known as the monolithic kernel. It is an old type of operating system. They were used in banks to do small tasks such as batch processing and time-sharing. The monolithic kernel serves as a virtual machine that manages all hardware components. It is not the same as a microkernel, which has limited tasks. There are two parts to a microkernel: kernel space and userspace. Both of these components communicate with others via IPC (Inter-process communication). The benefit of using a microkernel is that if one server fails, the other takes control. Monolithic architecture operating systems were first used in the 1970s.

Monolithic operating systems have three major layers: the application layer, the monolithic kernel, and the hardware layer. Every application in these operating systems has its own address space. As a result, the applications are safer. The kernel manages the operating system services, including the file system, memory manager, and CPU scheduler.

Advantages and disadvantages of Monolithic operating system

There are various advantages and disadvantages of a monolithic operating system. Some of them are as follows:

Advantages

1. The monolithic kernel runs quickly because of memory management, file management, process scheduling, etc. These are all implemented in the same address space.
2. Its structures are easy and simple. The kernel contains all of the components required for processing.
3. All of the components may interact directly with each other's and also with the kernel.
4. It works better for performing smaller tasks because it may handle limited resources.

Disadvantages

1. Monolithic OS has more tendency to generate errors and bugs. It's because user programs use the same address spaces as the kernel.
2. It isn't easy to port code written in the monolithic operating system.
3. It is very difficult to add and remove features from a monolithic operating system. All of the code must be modified and recompiled to add or remove a feature.

What is a Layered Operating System?

An operating system with different layers for handling system software and user software is known as a layered operating system. The lower layers are the responsibility of core system software, while the above layers are responsible for handling application software.

A layered operating system that has divided into multiple layers, and each layer serves as a certain task. The goal of developing layered operating systems is to get around monolithic operating systems' limitations. It was created to improve existing structures such as UNIX's Monolithic and Simple structures (MS-DOS).

There are mainly six layers in the layered operating system. These layers are as follows:

1. Hardware

The OS architecture's the lowest layer, and it is where the hardware devices are handled.

2. CPU Scheduling

It manages the scheduling tasks and schedules the processes for the CPU.

3. Memory Management

It manages the memory. It moves processes from disk to the primary memory for execution and returns the executed programs to disk.

4. Process Management

It handles the processes, and it also assigns the CPU to execute processes.

5. Input-Output Buffer

It allows the users to interface with the system and controls IO device buffers, and ensure that IO devices work properly.

5. User Programs

It is associated with the user programs like word processors, browsers, etc. All the programs are handled in this layer.

Advantages and disadvantages of layered operating system

There are various advantages and disadvantages of a layered operating system. Some of the advantages and disadvantages are as follows:

Advantages

1. Easy Debugging

It is very simple to debug because the layers are discrete. If an error happens in the CPU scheduling layer, the developer may only debug that layer.

2. Modularity

This design supports modularity because each layer only executes tasks it is scheduled to perform.

3. Abstraction

Each layer is concerned with its own set of functions. As a result, the functions and implementations of the other layer are abstract to it.

4. Easy update

A modification in one layer does not affect the other layers.

Disadvantages

1. Complex and better implementation

Layer layout is important because a layer can utilize the services of the layers below it. For example, the backup storage layer uses the memory management layer's services, so it must be stored beneath the memory management layer.

2. Slower in execution

When one layer wishes to interact with another, it sends a request that must traverse all layers between the two layers to be fulfilled. It enhances response time, which is faster than the Monolithic system. As a result, increasing the number of layers may lead to a very inefficient design.

Main differences between the monolithic and layered operating system

Here, you will learn the main differences between the monolithic and the layered operating system. There are various main differences between the monolithic and the layered operating system. Some of the differences are as follows:

1. A monolithic operating system is one in which the complete operating system operates in the kernel space. On the other hand, A layered operating system that has divided into multiple layers, and each layer serves as a specific task.
2. There are mainly three layers in the monolithic operating system. In contrast, a layered operating system has multiple layers.

Head-to-head comparison between the monolithic and layered operating system

Here, you will learn the head-to-head comparison between the monolithic and the layered operating system. There are various comparisons between the monolithic and the layered operating system. Some of them are as follows:

Conclusion

There are two types of operating systems: monolithic and layered. The monolithic operating systems run in kernel space. In contrast, a layered operating system that has divided into multiple layers, and each of these layers serve as a specific task.