Skip to main content

Operating system and it's functions

"An Operating System is an interface between the computer user and the computer hardware".

An operating system is an program that manages the computer hardware.Basically, a computer system can be divided roughly into four components the hardware the operating system the application programs and the users. It controls and coordinate the use of hardware among the various application programs for various users.
We have various operating systems available. Some popular operating system are: Linux, Unix, windows operating system which is mostly used these days, MAC operating system (specifically used by "apple").

Main Functions of Operating System:
1. Process management
2. Main Memory management
3. File management
4. Input/Output management
5. Secondary storage management

Process Management:
A program is a passive entity such as content of a file stored in disk, whereas a process is an active entity, with a program counter specifying the next instruction to execute. A process is a unit of work in a system.
The operating system is responsible for the following activities in connection with the process management:
  • Creating and deleting both user and system processes
  • Suspending and resuming the processes
  • Providing mechanism for process synchronism
  • Providing mechanism for deadlock handling and process communication
Main memory management: As we know the main memory is Central to the operation of a modern computer system. Main memory is a large array of words or bytes, ranging in size from hundreds of thousands to billions.
The operating system is responsible for the following activities in connection with memory management:
  • Keeping track of which parts of memory are currently being used and by whom.
  • deciding which processes are to be loaded into memory and when memory space is become available.
  • Allocating and deallocating memory space as needed.

File Management: A file is a collection of related information defined by its creator.
The operating system is responsible for the following activities in connection with the file management:
  • Creating and deleting files
  • Creating and deleting directories
  • Supporting primitives for manipulating files and directories
  • Mapping files onto secondary storage
  • Backing up files on stable storage media

Input/Output Management: One of the purposes of an operating system is to hide the peculiarities of specific hardware devices from the user. For example in Unix the peculiarities of input/output devices are hidden from the bulk of the operating system itself by the input/output subsystem.
The input/output subsystem consist of:
  • General device driver interface
  • Driver for specific hardware devices

Secondary storage management: The main purpose of a computer system is to execute programs. These programs with the data access must be in main memory or primary memory during execution. Because main memory is too small to accommodate all data and because the data that it holds are lost when power is lost so the computer system must provide to backup main memory.

So, the operating system is responsible for the following activities in connection with the disk management:
  • Free space management
  • Storage allocation
  • Disk scheduling

Also operating system provides services to programs and two uses of those programs, such as program execution. Error detection and resource allocation.

Labels

Labels:

Comments

Post a Comment

If you find something wrong about this post please let us know. No Abusive Messages please.

Popular posts from this blog

Data Warehousing

  Data Warehouse is open to an almost limitless range of definitions. Simply put, data warehouses store and aggregation of a company's data. Data warehouses are an important asset for organisations to maintain efficiency, profitability and competitive advantages, organisations collect data through many sources- online, call centre, sales needs, inventory management. The data collected have degrees values and business relevance. Figure shown below shows the architecture of a typical data warehouse and illustrate the gathering of data, the storage of data, and the quaring and data analysis support. Different steps involved in getting data into a warehouse are called as extract, transform and lode or ELT tasks; extraction refers to getting data from the sources, while loaders reference to loading the data into data warehouse. Characteristics of data warehouse: Multidimensional conceptual view Generic dimensionality Unlimited dimensions and aggregation le...
3 comments
Read more

DBMS: Normalization

Normalization : Normalization is the process of transformation of the conceptual schema of the database into a computer represent table form. Normalization is the process of removing the redundancies from incoming data.  Normalization is a technique to which helps the user to group the data and place the data in a table.  Normalization is a process which ensure the inconsistencies are not introduced into the database. Need of Normalization : we know with the time, most of databases grow time to time by adding new relations and relationships, the data may be used in different ways. Regularly the information may undergo series of updations in such situations, the performance of a database is entirely dependent upon its design.      A bad  database design  may lead to certain undesirable things: Repetition of information Inability to represent certain information  Loss of information Uses of Normalization: When data is large a...
1 comment
Read more

Hub, repeater, switch, router, gateway, bridge

HUB Hub is a controller that controls the traffic on the network.  The following important properties of hub are:  1) It amplify signals. 2) It propagates signals through the network. 3) It does not require filtering. 4) It does not require path determination for switching. 5) It is used as network concentration points. Hubs are basically two types: 1) Active hub 2) Passive hub Active hub: A ctive hub works as repeater which is a hardware device that regenerates the received bit pattern before sending them out . Passive hub : A passive hub is a simple hardware device which provide a simple physical connection between the attached devices. Advantages of hub: It cannot filter the traffic full stop feeling generally refers to a process or device that screens network traffic for certain characteristics such as source address and destination address and protocol. Disadvantages of hub: On a hub, more than one user may try to send data on the netwo...
1 comment
Read more