by Dinesh Thakur Category: Operating System

A time sharing system allows many users to share the computer resources simultaneously. In other words, time sharing refers to the allocation of computer resources in time slots to several programs simultaneously. For example a mainframe computer that has many users logged on to it. Each user uses the resources of the mainframe -i.e. memory, CPU etc. The users feel that they are exclusive user of the CPU, even though this is not possible with one CPU i.e. shared among different users.



 
by Dinesh Thakur Category: Operating System

To overcome the problem of underutilization of CPU and main memory, the multiprogramming was introduced. The multiprogramming is interleaved execution of multiple jobs by the same computer.



 
by Dinesh Thakur Category: Operating System

To avoid the problems of early systems the batch processing systems were introduced. The problem of early systems was more setup time. So the problem of more set up time was reduced by processing the jobs in batches, known as batch processing system. In this approach similar jobs were submitted to the CPU for processing and were run together.

 
by Dinesh Thakur Category: Operating System

Following are the services provided by an operating system for the convenience of users:

  1. Program Execution

The purpose of computer system is to allow the users to execute programs in an efficient manner. The operating system provides an environment where the user can conveniently run these programs. The user does not have to worry about the memory allocation or de-allocation or any other thing because these things are taken care of by the operating system.



 
by Dinesh Thakur Category: Operating System

A computer system can be divided into five components; the hardware, the operating system, the utilities, the application programs and the end users. Following diagram shows the actual position of an operating system among these components.



 
by Dinesh Thakur Category: Operating System

Spooling - simultaneous peripheral operations on-line, spooling refers to as a process that putting jobs in a buffer or say spool, or temporary storage area, a special area in memory or on a disk where a device can access them when it is ready. Spooling is useful because devices access data at different rates.

 
by Dinesh Thakur Category: Operating System

Operating System is the System Software that makes the Computer work. We can say that an Operating System (OS) is Software that acts as an interface between you and the hardware. It not only contains drivers used to speak the hardware's language, but also offers you a very specific graphical user interface (GUI) to control the computer.



 
by Dinesh Thakur Category: Operating System

Real Time System : There is also a Operating System which is known as Real Time Processing System. In this Response Time is already fixed. Means time to Display the Results after Possessing has fixed by the Processor or CPU.

 
by Dinesh Thakur Category: Operating System

Marshalling is the process of gathering data and transforming it into a standard format before it is transmitted over a network so that the data can transcend network boundaries.

 
by Dinesh Thakur Category: Operating System

Memory partitioning is the way to distribute the Kernel and User Space Area in Memory.

Paging is actually a minimum memory, which can be swap in and swap out from Memory. In modern Server operating systems, we can use Multiple Page Size Support. That actually helps to tune OS performance, depending on type of applications.



 
by Dinesh Thakur Category: Operating System

The Demand Paging is also same with the Simple Paging. But the Main Difference is that in the Demand Paging Swapping is used. Means all the Pages will be in and out from the Memory when they are required. When we specify a Process for the Execution then the Processes is stored firstly on the Secondary Memory which is also known as the Hard Disk.

 
by Dinesh Thakur Category: Operating System

Definition: Virtual memory is the feature of an operating system (OS). It is responsible for memory management.In the Virtual Memory the Physical Memory (Hard Disk) will be treated as the Logical Memory (random access memory (RAM)). Means with the help of virtual Memory we can also temporarily increase the size of Logical Memory as from the Physical Memory. A user will see or feels that all the Programs are running into the Logical Memory of the Computer. With the help of virtual Memory all the Space of Hard Disk can be used as the Logical Memory So that a user can execute any Number of programs.



 
by Dinesh Thakur Category: Operating System

As we know that operating system is that which executes the system and the operating system is the software which is responsible for running all the user programs so that generally memory is divided in to the two parts, first part is used by the operating system and the second part is used by the user programs and there may be some situations that the memory size of the operating system may be higher from the user memory and also vice versa.



 
by Dinesh Thakur Category: Operating System

As we know that there are many problems arise in the continues memory allocation so that we uses the concept of the dynamic memory allocation. In the dynamic memory allocation memory is divided into the various partitions at the run time.

 
by Dinesh Thakur Category: Operating System

For improving the performance of the system we use the concept of swapping. In the swapping the processes those are on waiting state and those are on suspend or temporary suspend will be stored from out side the memory locations so that the speed of process will be high.

 
by Dinesh Thakur Category: Operating System

As we know that memory is that which stores the programs and these programs are used by the CPU for processing.  Moreover, there are two types of memories first is the logical memory and second is the physical memory. The memory which is temporary such as ram is also known as the temporary memory, and the memory which is permanent such as the hard disk is also known as the physical memory of the system.

 
by Dinesh Thakur Category: Operating System

Process Control block is used for storing the collection of information about the Processes and this is also called as the Data Structure which Stores the information about the process. The information of the Process is used by the CPU at the Run time. The various information which is Stored into the PCB as followings:



 
by Dinesh Thakur Category: Operating System

Files are used for storing the Information of the user. Generally for arranging all the Files directories or Folders are used. A Folder or Directory is also called as the Container of the Files in which many Sub directors and Files are Stored. So that Files System Specifies the Arrangement of the Files in the System. There are following Directory Structures Available for organizing all the Files.

 
by Dinesh Thakur Category: Operating System

File System: Files are used for storing the Information of the user; But Files are organized into the System by using a Specific Manner. Generally for arranging all the Files, directories or Folders are used.

 
by Dinesh Thakur Category: Operating System

The Concept of File Sharing and Locking is used in the Multi-users Environment, or in which there are many users those are Requesting for a Single File, to Perform Some Operations.

 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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