Device Management in Operating System

What is Device Management in an Operating System?

We have many input devices for computers like keyboard, mouse, scanner, microphone, etc and there are output devices like printer, speakers, etc. Other than these, there are other hardware devices such as Disk, USB, etc. Also, there are some virtual devices that are not associated with the hardware but work similarly to hardware devices. As all the processes of a PC are controlled or handled by the operating system, the hardware devices, and virtual devices are handled by the Device Management system of the Operating system.

A process can demand many resources and if the resources are not available then the process is halted until the required resources are free, and if the resources are available they are allocated to the process. The operating system and hardware or the devices of the computer are not connected directly to each other they are connected to each other through special programs known as drivers.

The main function of the drivers is to act as the translator between the high-level programming language of the operating system and the electric signals of the hardware devices. Drivers add one more advantage as performing translator between the Operating system and the Hardware that, it's easy to update drives as compared to updating the operating system. So after updating hardware or for different sets of hardware same operating system can work.

Functions of the Device Management in the Operating System

As we have seen above, the operating system manages devices with the help of drivers and makes sure to use the particular device in the way it is supposed to work. There are various functions of the device management system in the operating system, let’s look into them:

• The device management system works as the Input/Output controller which means it keeps track of all the device's data, location, status, etc.
• The device management system in the Operating system creates schedules and decides on the basis of priority which process will hold a particular device and for how long it will hold it.
• The device management system helps in the improvement of the drivers.
• The device management system in the Operating system allocates and deallocates the devices. The deallocation process has been done two times, first when the process release device temporarily due to the Input/Output command, and second when the job is finished and the device is released permanently.
• It looks for every single hardware or virtual device and keeps the status of each of them.

Types of Device Management in Operating System

Before moving to the type of device management in the operating system let's look into the fundamental type of Input/Output devices, which are divided into three categories:

• Boot Device
• Character Device
• Network Device

Let's discuss above mentioned three types of devices in detail:

1. Boot Device: Boot devices are the part of the hardware which consists of the data or files necessary to start the computer or PC. Hard disk, CD-ROM drive, floppy disk drive, DVD drive, and USB jump drive come under the Boot Device category.

2. Character Device: Any device in which to give input or take the output the stream of characters is passed as they don’t have their own memory are known as character devices.

3. Network Device: The devices help to connect the computer to a network by transmitting the data packs known as network devices.

With respect to the operating system the hardware or virtual devices are divided into three parts:

• Dedicated Devices
• Shared Devices
• Virtual Device

Let's discuss above mentioned three types of devices in detail:

1. Dedicated Devices There are many devices when they are allocated to a process, they are not released until the job is completed. The reason for this is it is not efficient to switch them between two or more devices and sometimes not allocating devices until the job is done becomes a disadvantage because, if the current process is not taking 100% use of it then also we cannot deallocate it. Printers, plotters, tape drivers, etc are examples of such devices.

2. Shared Devices Devices that can be shared or allocated between two or more processes at the same time are known as shared devices. For sharing the same device between two or more processes device manager must carefully control the interleaving, and all the pre-determined policies are resolved. HDDs or SDDs, tape silos, optical jukeboxes, etc. are some examples of shared devices.

3. Virtual Devices The third type of device or virtual device is the combination of the above two discussed devices means when the dedicated devices are converted into shared devices then they are known as virtual devices. The best example of a virtual device is the printer. A printer can be transformed into a shared device from the dedicated device by using the spooling program, in which all the requests to the printer are redirected to a disk. By converting a dedicated device to a shared device we can create many virtual instances of the current device and can increase its efficiency.

Features of Device Management in Operating System

We have seen the functions of the Device management system in the Operating system in the above article now let’s look at the features it provides:

1. To communicates with the device controllers to allocate the device to the various processes running on the computer the device management operating system takes the help of the device drivers.
2. Device drivers are the software programs that work as the translator between the hardware signals and the high-level programming language of the operating system and are used to control the functioning of devices in the proper or expected manner.
3. Command, status, and data registers are mainly used by the device controller in the device management operating system.
4. As we have discussed above the device drivers are mediators between the software and hardware.
5. Application Programming Interface or API is the set of programs or functions that allows the application to interact with the software and the data is handled by the device management operating system.