Device Management in Operating System


An essential part of an operating system is device management, which controls how software applications interact with the hardware attached to the computer system. It entails the process of locating, setting up, allocating, and managing access to devices like printers, scanners, storage units, and network interfaces. The device management system guarantees that the hardware devices are used effectively by the system software and applications by providing a consistent and dependable interface to the hardware devices. It also covers input/output control, error handling, and interrupt management. The operating system may more effectively utilize the resources at its disposal thanks to the device management system, which also enhances the computer system's overall performance.

Device Drivers

Device drivers are software programs that enable the operating system to communicate with the hardware devices attached to the computer system. A device driver acts as a translator between the operating system and the hardware device, providing a standard interface for the operating system to interact with the device.

The function of a device driver is to facilitate communication between the operating system and the device hardware, and to enable the operating system to control and manage the device. There are different types of device drivers that are designed to handle different types of hardware devices. Here are three common types of device drivers −

  • Character device driver − Devices that send data character by character are controlled by character device drivers. Keyboards, mice, printers, and terminals are some of these gadgets. Character device drivers function by buffering the data that is received from the hardware device until the operating system is prepared to process it.

  • Block device driver − Hard disc drives and solid-state drives are examples of devices that transfer data in fixed-size blocks and are managed by block device drivers. Block devices offer random access to data, which allows data to be retrieved in any sequence as opposed to sequential reading. A standard interface for file systems to access the data on the device is provided by block device drivers, which also control the data flow between the operating system and the block device.

  • Network device driver − Network device drivers are used to manage network interface devices such as Ethernet cards and Wi-Fi adapters. Network device drivers provide the operating system with the ability to communicate with other devices on a network. These drivers are responsible for handling data packets received from the network, as well as sending packets to other devices.

Device Management Architecture

Device management can be performed at both the kernel level and the user level of an operating system.

  • Kernel level − The administration of hardware components at the lowest level of the operating system, the kernel, is known as kernel-level device management. Device drivers are managed by the kernel-level device management, which also acts as a low-level interface between the hardware and the operating system. The control of hardware devices at the kernel level is very effective and gives users direct access to the hardware. Yet, because it has the highest degree of privileges and can impact the stability of the entire operating system, kernel-level device management can be dangerous.

  • User level − User-level device management involves managing the hardware devices at the user level, outside the kernel. In user-level device management, the device drivers run in user space, providing a layer of protection to the kernel. User-level device management is less efficient than kernel-level device management, as it requires more processing time and resources. However, user-level device management is safer than kernel-level device management, as it provides a layer of protection to the operating system.

Device Allocation Techniques

Device allocation techniques are used to manage the allocation of hardware resources, such as input/output (I/O) devices, to different processes or users in an operating system. There are two main techniques for device allocation: static allocation and dynamic allocation.

  • Static allocation − Static allocation is a technique in which devices are assigned to processes or users at system startup and remain assigned until the system is shut down. In static allocation, the operating system allocates specific devices to specific processes or users based on predetermined criteria, such as priority, device type, or user ID. Static allocation is simple and efficient, but it can lead to inefficient use of resources if a device is not being fully utilized by the process or user it is assigned to.

  • Dynamic allocation − Devices are temporarily allocated to processes or users using a technique called dynamic allocation. When devices are allocated dynamically, the operating system assigns them to users or processes depending on their current requirements and releases them when no longer required. Resources can be used more effectively thanks to dynamic allocation because devices can be assigned to various processes or users according to demand. Dynamic allocation, on the other hand, necessitates more intricate management algorithms, increases complexity, and raises the possibility of conflicts between processes or users.

Input/Output Control

I/O control refers to the process of managing input/output (I/O) operations in an operating system. The primary function of I/O control is to coordinate the flow of data between the central processing unit (CPU) and the I/O devices, such as keyboards, mice, printers, and disk drives. I/O control is responsible for controlling the access to these devices and for providing a unified interface for different types of devices. There are two main types of I/O control: programmed I/O and direct memory access (DMA).

  • Programmed I/O − Programmed I/O is the most basic type of I/O control, where the CPU is responsible for managing all aspects of the I/O operation. In programmed I/O, the CPU sends a command to the device to initiate an I/O operation, waits for the device to complete the operation, and then retrieves the data from the device. This process requires a significant amount of CPU overhead and can be slow and inefficient.

  • Direct Memory Access (DMA) − Direct Memory Access (DMA) is a more advanced type of I/O control that allows data to be transferred directly between memory and I/O devices without requiring CPU intervention. In DMA, a DMA controller is used to manage the transfer of data between the I/O device and memory. The CPU sets up the DMA controller with the appropriate parameters for the transfer and then releases control of the system while the DMA controller performs the transfer. Once the transfer is complete, the DMA controller generates an interrupt to signal the CPU to retrieve the data.

There are also various kinds of techniques to improve the performance of the I/O operations. Buffering and caching are one of them.

  • Buffering − It is the process of temporarily storing data that is being transferred between an I/O device and memory in a buffer. Buffers are used to improve performance by allowing I/O operations to continue while the CPU is performing other tasks. When an I/O operation is initiated, data is transferred to the buffer, and the CPU can continue executing other instructions while the data is being transferred. Once the data transfer is complete, the CPU can retrieve the data from the buffer at its convenience. Buffering can be implemented in hardware or software and is commonly used in file systems and network protocols.

  • Caching − It is the process of storing frequently accessed data in a cache to improve performance. A cache is a small amount of memory that is used to store recently accessed data. When an I/O operation is initiated, the data is retrieved from the cache instead of from the disk or other I/O device. This can significantly improve the performance of I/O operations, as accessing data from memory is much faster than accessing data from an I/O device. Caching is commonly used in file systems, web browsers, and database systems.


As a result of regulating the interface between computer hardware and software, device management is a crucial component of operating system architecture. Operating systems allocate and manage hardware devices using a variety of strategies and use device drivers to connect with these devices. Character and block drivers are the two main categories of device drivers, whereas network drivers are used to control network interfaces.

Updated on: 04-Apr-2023

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